Weimar, W.

Tacrolimus Inhibits NF-κB Activation in Peripheral Human T Cells (Article)

2013-04-01T00:00:00Z

The calcineurin inhibitor, tacrolimus (TAC), inhibits the protein phosphatase activity of calcineurin, leading to suppression of the nuclear translocation of NFAT and inhibition of T cell activation. Apart from NFAT also the transcription factor NF-κB plays a key functional role in T cell activation. Therefore, blockade of the NF-κB activation cascade by immunosuppressive drugs prevents immune activation. Here we studied whether TAC blocks NF-κB activation in peripheral human T cells. After anti-CD3/CD28-activation of T cells from healthy volunteers, NF-κB (p65) phosphorylation was measured by flow cytometry in CD3+ T cells, CD4+ helper T cells and CD8+ cytotoxic T cells in the absence and presence of TAC 10 ng/mL, sotrastaurin 500 nM (positive control) and mycophenolic acid 10 μg/mL (negative control; n = 6). NF-κB transcriptional activity was measured by ELISA and intracellular TNFα protein, a downstream target, was measured by flow cytometry to assess the functional consequences of NF-κB blockade. Anti-CD3/28-activation induced NF-κB phosphorylation in CD3+ T cells, CD4+ T cells and CD8+ T cells by 34% (mean), 38% and 30% resp. (p<0.01). Sotrastaurin inhibited NF-κB activation in the respective T cell subsets by 93%, 95% and 86% (p<0.01 vs. no drug), while mycophenolic acid did not affect this activation pathway. Surprisingly, TAC also inhibited NF-κB phosphorylation, by 55% (p<0.01) in CD3+ T cells, by 56% (p<0.01) in CD4+ T cells and by 51% in CD8+ T cells (p<0.01). In addition, TAC suppressed NF-κB DNA binding capacity by 55% (p<0.05) in CD3+ T cells and TNFα protein expression was inhibited in CD3+ T cells, CD4+ T cells and CD8+ T cells by 76%, 71% and 93% resp. (p<0.01 vs. no drug), confirming impaired NF-κB signaling. This study shows the suppressive effect of TAC on NF-κB signaling in peripheral human T cell subsets, measured at three specific positions in the NF-κB activation cascade.

Genetic variants of FOXP3 influence graft survival in kidney transplant patients (Article)

2013-03-25T00:00:00Z

FOXP3+regulatory T cells (Treg) play a role in controlling alloreactivity. It has been shown that short (GT)ndinucleotide repeats (≤(GT)15; S) in the promoter region of the FOXP3 gene enhance the promoter activity when compared to long (GT)nrepeats (≥(GT)16; L). The present study retrospectively investigated the influence of this (GT)nFOXP3 gene polymorphism on renal allograft survival. A total of 599 consecutive first-time kidney transplant patients (median follow-up time 7.7 years) were subdivided according to their FOXP3 genotype into the S-genotype group (SG) and the L-genotype group (LG). The SG was superior to the LG in both general graft survival censored for death (logrank test, p = 0.013) and graft survival following acute rejection (p = 0.021). Multivariate analysis defined the (GT)nFOXP3 dinucleotide repeat polymorphism as an independent factor and confirmed an advantage for the SG in renal allograft survival (HR = 0.67, 95% CI 0.48-0.94, p = 0.02). This gene association study identified a beneficial effect of FOXP3 genetic variants on graft survival in kidney transplant patients.

Systematic review and meta-analysis of the relation between body mass index and short-term donor outcome of laparoscopic donor nephrectomy (Article)

2013-01-23T00:00:00Z

In this era of organ donor shortage, live kidney donation has been proven to increase the donor pool; however, it is extremely important to make careful decisions in the selection of possible live donors. A body mass index (BMI) above 35 is generally considered as a relative contraindication for donation. To determine whether this is justified, a systematic review and meta-analysis were carried out to compare perioperative outcome of live donor nephrectomy between donors with high and low BMI. A comprehensive literature search was performed in MEDLINE, Embase, and CENTRAL (the Cochrane Library). All aspects of the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement were followed. Of 14 studies reviewed, eight perioperative donor outcome measures were meta-analyzed, and, of these, five were not different between BMI categories. Three found significant differences in favor of low BMI (29.9 and less) donors with significant mean differences in operation duration (16.9 min (confidence interval (CI) 9.1-24.8)), mean difference in rise in serum creatinine (0.05 mg/dl (CI 0.01-0.09)), and risk ratio for conversion (1.69 (CI 1.12-2.56)). Thus, a high body mass index (BMI) alone is no contraindication for live kidney donation regarding short-term outcome.Kidney International advance online publication, 23 January 2013; doi:10.1038/ki.2012.485.

Living organ donation practices in Europe - results from an online survey (Article)

2012-12-04T00:00:00Z

In Europe, living organ donation (LOD) is increasingly accepted as a valuable solution to overcome the organ shortage. However, considerable differences exist between European countries regarding frequency, practices and acceptance of donor-recipient relations. As a response, the Coordination Action project 'Living Organ Donation in Europe' (www.eulod.eu), funded by the Seventh Framework Programme of the European Commission, was initiated. Transplant professionals from 331 European kidney and liver transplant centres were invited to complete an online survey on living kidney donation (LKD) and living liver donation (LLD). In total, 113 kidney transplant centres from 40 countries and 39 liver transplant centres from 24 countries responded. 96.5% and 71.8% performed LKD and LLD respectively. The content of the medical screening of donors was similar, but criteria for donor acceptance varied. Few absolute contraindications for donation existed. The reimbursement policies diverged and the majority of the donors did not get reimbursed for their income loss during recovery. Large discrepancies were found between geographical European regions (the Eastern, the Mediterranean and the North-Western). As a result of this survey we suggest several recommendations to improve quality and safety of LOD in Europe.

Unspecified donation in kidney exchange: when to end the chain (Research Paper)

2012-12-01T00:00:00Z

This paper studies participation of unspecified donors in kidney exchange through simultaneous domino paired donation (DPD) and non-simultaneous extended altruistic donor (NEAD) chains. It extends existing research by investigating the termination of chains, the possibility of transplantation across the blood type barrier, and the impact of incentives in multi-center exchanges. Furthermore, it looks into the effect of various configuration parameters such as the time interval between exchanges. Our analysis is based on a simulation study that uses data of all 438 patient-donor pairs and 109 unspecified donors who were screened at Dutch transplant centers between 2003 and 2011. Because multi-center coordination may raise incentive issues, special attention is paid to individually rational implementation. We find that chains are best terminated when no further segment is part of an optimal exchange within 3 months. Transplantation across the blood type barrier allows for longer continuation of chains, more transplants and more equity among patient groups. NEAD chains perform slightly better than DPD chains, provided that the renege rate is sufficiently low. Additional substantial gains are due to national individually rational coordination. Particularly highly sensitized and blood type O patients benefit. Appropriate timing of ex-changes can further improve these results.

Systemic varicella zoster virus reactive effector memory T-cells impaired in the elderly and in kidney transplant recipients (Article)

2012-12-01T00:00:00Z

Varicella zoster virus (VZV) infections cause varicella and subsequently herpes zoster upon reactivation. Immune-compromised individuals and the elderly are at high risk of developing herpes zoster due to waning of VZV-specific T-cell immunity. In the present study, a novel functional T-cell assay was developed to test the correlation between age and VZV-specific T-cell responses in peripheral blood from healthy individuals. Secondly, VZV-specific T-cell responses from renal transplant recipients were compared with healthy individuals. Monocytes were differentiated into mature monocyte-derived dendritic cells (moDCs) and were infected with VZV. T-cells were co-cultured with autologous moDCs infected with VZV and subjected to flowcytometric analysis to identify the phenotype (i.e., naïve [NA: CCR7+CD45RO-], central [CM: CCR7+CD45RO+] and effector memory [EM: CCR7-CD45RO+] T-cells) and the frequency of VZV-reactive T-cell subsets by intra-cellular IFN-γ flowcytometry. In contrast to NA and CM T-cells, the frequency of VZV-reactive CD4 and CD8 EM T-cells was inversely correlated with age (P=0.0007 and P=0.01). No difference was found in the percentage of VZV-reactive CD4 NA, CM and EM T-cells between transplant recipients and controls. However, the percentage of VZV-reactive CD8 EM T-cells was significantly lower in transplant recipients compared to controls (P=0.02). In conclusion, moDCs infected with VZV are efficient antigen presenting cells applicable to enumerate and characterize the phenotype and differentiation status of the systemic VZV-specific T-cell response ex-vivo. The data suggest that VZV-reactive EM T-cells are impaired in the elderly and renal transplant recipients.

Mesenchymal stem cells derived from adipose tissue are not affected by renal disease (Article)

2012-10-01T00:00:00Z

Mesenchymal stem cells are a potential therapeutic agent in renal disease and kidney transplantation. Autologous cell use in kidney transplantation is preferred to avoid anti-HLA reactivity; however, the influence of renal disease on mesenchymal stem cells is unknown. To investigate the feasibility of autologous cell therapy in patients with renal disease, we isolated these cells from subcutaneous adipose tissue of healthy controls and patients with renal disease and compared them phenotypically and functionally. The mesenchymal stem cells from both groups showed similar morphology and differentiation capacity, and were both over 90% positive for CD73, CD105, and CD166, and negative for CD31 and CD45. They demonstrated comparable population doubling times, rates of apoptosis, and were both capable of inhibiting allo-antigen-and anti-CD3/CD28-activated peripheral blood mononuclear cell proliferation. In response to immune activation they both increased the expression of pro-inflammatory and anti-inflammatory factors. These mesenchymal stem cells were genetically stable after extensive expansion and, importantly, were not affected by uremic serum. Thus, mesenchymal stem cells of patients with renal disease have similar characteristics and functionality as those from healthy controls. Hence, our results indicate the feasibility of their use in autologous cell therapy in patients with renal disease.

An ELPAT definition of the concept ‘Psychosocial’ in the context of Screening Living Organ Donors in Europe: A Concept Mapping approach (Report)

2012-10-01T00:00:00Z

Abstract Introduction: Across Europe, transplant centers vary in the set of psychosocial screening criteria/guidelines used for the selection of eligible living donors. Our aim was to explore whether a common framework underlies this variation in screening criteria and, based on this framework, to develop a consensus on the essential elements of psychosocial screening of living liver and kidney donors. In order to do so, a research question was set out to define a conceptual framework of the concept ‘Psychosocial’ in the context of screening living organ donors in Europe. We formulated the following research question: Which psychosocial screening criteria are most commonly reported and considered as most important or effective in selecting eligible kidney and liver donors? Method: Concept mapping methodology was used to create a visual representation of the complex topic ‘Psychosocial’ in the context of screening living organ donors in Europe, in which underlying concepts, the relative importance of these concepts and the interplay between different concepts are organized. Initial psychosocial screening criteria (N=83) were derived from an extensive systematic literature review on guidelines, protocols and consensus statements on psychosocial screening practices, complemented by group brainstorm sessions. These criteria were then sorted and rated for their importance and effectiveness by 26 project participants. The data were analyzed using the Concept System Core© Software, which provided us with graphical depictions (concept maps) illustrating the view of project participants on these screening criteria. Pattern Matches and Go-Zones showed us the highlycommon, important and effective criteria. Results: The concept map procedure resulted in six clusters of psychosocial screening criteria: (1) Motivation and decision making (2) Personal resources (3) Psychopathology (4) Social resources (5) Ethical and Legal factors (6) Information and risk processing. Bivariate rating of these criteria revealed which important criteria are already frequently used for screening and which require more attention. Based on the cluster map and bivariate ratings we constructed a conceptual framework for non-medical risk factors that need to be considered when screening potential living organ donors. Conclusion: We provided a conceptual framework of psychosocial screening criteria which can serve as a practical recommendation for the psychosocial screening of potential living organ donors.

The functional polymorphism Ala258Ser in the innate receptor gene ficolin-2 in the donor predicts improved renal transplant outcome (Article)

2012-09-15T00:00:00Z

BACKGROUND: Innate immunity plays a role in controlling adaptive immune responses. METHODS: We investigated the clinical relevance of single nucleotide polymorphisms in 22 genes encoding innate, secreted, and signaling pattern recognition receptors in a total of 520 donor-recipient pairs of postmortem, human leukocyte antigen-DR-compatible kidney transplantations. Associations with rejection incidence were tested in an a priori randomized training set and validation set. RESULTS: Polymorphisms in TLR-3 (rs3775296) in the recipients and in Ficolin-2 (rs7851696; Ala258Ser) and C1qR1 (rs7492) in the donors showed the strongest association with severe rejection. In multivariate analysis, presence of the Ficolin-2 Ala258Ser variant in the donor predicted lower incidence of severe rejection (odds ratio=0.3; 95% confidence interval, 0.1-0.9; P=0.024) and of graft loss (hazard ratio=0.5; 95% confidence interval, 0.2-1.0; P=0.046) independently of clinical risk factors. Ficolin-2 messenger RNA expression was detected in pretransplantation biopsies from 69 donor grafts. Serum and tissue Ficolin-2 levels were unaffected by genotype. Ficolin-2 protein, which bound to dying cells, was detected in donor kidneys in a passenger leukocyte-like pattern. Indeed, monocytes, monocyte-derived macrophages, and peripheral blood mononuclear cells expressed Ficolin-2. Donor grafts with the Ficolin-2 Ala258Ser variant contained significantly elevated expression of interleukin 6, having ascribed cytoprotective effects. It has been described that Ala258Ser leads to increased binding capacity of Ficolin-2 to N-acetylglucosamine. CONCLUSIONS: Presence of the Ficolin-2 Ala258Ser polymorphism in the donor independently predicts improved graft outcome. Based on mechanistic data, we propose that this functional polymorphism leads to more efficient handling of injured cells by phagocytozing cells, resulting in decreased intragraft exposure to danger signals and dampened alloimmune responses. Copyright

Pharmacodynamic analysis of tofacitinib and basiliximab in kidney allograft recipients (Article)

2012-09-15T00:00:00Z

BACKGROUND: The common γ-chain (γc) cytokines signal through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway and play pivotal roles in lymphocyte activation. We investigated the effect of immunosuppressive drugs targeting this pathway, the JAK inhibitor tofacitinib (CP-690,550) and the anti-interleukin (IL)-2R antibody basiliximab, as part of a phase 2 study. METHODS: After whole-blood activation with the γccytokines IL-2, IL-7, and IL-15, STAT5 phosphorylation was determined in T cells of de novo kidney transplantation patients treated with tofacitinib/basiliximab (n=5), calcineurin inhibitor (CNI) (cyclosporine A)/basiliximab (n=4) or CNI (tacrolimus)-based immunosuppression (n=6). The IC50 for phosphorylated STAT (P-STAT) 5 inhibition by tofacitinib was determined in cytokine-activated CD4+and CD8+T cells from healthy individuals (n=4). RESULTS: IC50 was 26, 72, and 37 ng/mL for IL-2, IL-7, and IL-15 activation, in CD4+T cells, respectively; and 35, 61, and 76 ng/mL for IL-2, IL-7, and IL-15 activation, in CD8+T cells, respectively. In kidney transplantation patients, 7 days after starting tofacitinib/basiliximab treatment, cytokine-induced P-STAT5 was inhibited in CD4+T cells (92% for IL-2 activation, 60% for IL-7, and 75% for IL-15), which persisted for the 2-month study period. In contrast, CNI/basiliximab treatment did not affect IL-7-activated or IL-15-activated P-STAT5; only IL-2-activated P-STAT5 was reduced by 77% on day 7 and recovered to pretreatment levels within 2 months. CD8+T cells showed a comparable profile to CD4+T cells. P-STAT5 was not inhibited in CNI-treated control patients. CONCLUSIONS: Tofacitinib therapy strongly inhibits γccytokine-induced JAK/STAT5 activation, whereas basiliximab suppresses IL-2-stimulated activation only. Pharmacodynamic monitoring offers a unique tool to evaluate the biologic effects of immunosuppressive drugs. Copyright

Phosphospecific flow cytometry for pharmacodynamic drug monitoring: Analysis of the JAK-STAT signaling pathway (Article)

2012-09-08T00:00:00Z

Cytokines of the IL-2 receptor family act via activation of the JAK-STAT (janus tyrosine kinase-signal transducer and activator of transcription) signaling pathway. These cytokines are pivotal for the development and function of lymphocyte subsets involved in the immune response after organ transplantation including T, B and natural killer cells. The new small drug molecule and JAK1/3 inhibitor, tofacitinib, is currently being tested in phase II and III clinical trials for rheumatoid arthritis, psoriasis and in organ transplantation. This agent specifically targets the JAK-STAT signaling pathway. Here we discuss phosphospecific flow cytometry as a novel tool to monitor the JAK-STAT signaling pathway in kidney transplant patients and speculate that through the use of this pharmacodynamic tool the efficacy of immunosuppressive drugs can be assessed enabling optimization of the immunosuppressive therapy for individual transplant patients.

Inhibitory effect of tacrolimus on p38 mitogen-activated protein kinase signaling in kidney transplant recipients measured by whole-blood phosphospecific flow cytometry. (Article)

2012-06-27T00:00:00Z

Tacrolimus (TAC), the cornerstone of immunosuppressive therapy after solid organ transplantation, inhibits calcineurin activation. Despite pharmacokinetic monitoring, patients frequently experience toxicity or lack of efficacy, which could be prevented by pharmacodynamic monitoring. In Jurkat T-cell lines, it has been shown that TAC, in addition to calcineurin, inhibits the p38 mitogen-activated protein kinase (MAPK) pathway, which is important in T-cell activation and is therefore a potential drug-specific biomarker. We studied whether TAC inhibits p38 MAPK signaling in primary human T cells and ex vivo in healthy volunteers and kidney transplant recipients. Phorbol-12-myristate-13-acetate/ionomycin-induced MAPK signaling was measured by whole-blood phosphospecific flow cytometry. In vitro, 10-ng/mL TAC inhibited p38 MAPK phosphorylation by a mean of 27% in CD3, 26% in CD4, and 34% in CD8 T cells (P<0.01 compared with baseline). In healthy adults (n=4), 2 hr after a single oral dose of 10-mg TAC, the p38 MAPK activation was inhibited by 35% in CD3, CD4, and CD8 T cells (P<0.05 compared with baseline). In kidney transplant recipients (n=24), TAC predose concentrations (range, 3.2-10.5 ng/mL) were inversely correlated with p38 MAPK activation in CD3, CD4, and CD8 T cells (r=0.51, 0.34, and 0.37, respectively; P<0.01). TAC inhibits activation of the MAPK pathway in a dose-dependent manner in kidney transplant patients and may be a potential marker for immune monitoring.

Quantifying the benefit of early living-donor renal transplantation with a simulation model of the Dutch renal replacement therapy population (Article)

2012-01-01T00:00:00Z

Background.Early living-donor transplantation improves patient-and graft-survival compared with possible cadaveric renal transplantation (RTx), but the magnitude of the survival gain is unknown. For patients starting renal replacement therapy (RRT), we aimed to quantify the survival benefit of early living-donor transplantation compared with dialysis and possible cadaveric transplantation and to estimate the population benefit from increasing the early transplantation rate. Methods.We used a decision-analytic computer-simulation model, with a lifetime time horizon, simulating patients starting RRT, using data from the Dutch End-Stage Renal Disease Registry and published data. We compared the (quality adjusted) life expectancy (LE) of 'early living-donor RTx' and 'dialysis' (with possible cadaveric RTx if available). Results.LE and quality-adjusted LE benefits of the early living-donor RTx compared with the dialysis strategy for 40-year-old patients ranged from 7.5 to 9.9 life years (LYs) [6.7-8.8 quality-adjusted life years (QALYs)] depending on the primary renal disease. For 70-year-old patients, the benefit was 4.3-6.0 LYs (4.3-6.0 QALYs). Increasing the early transplantation rate from currently 5.8 to 22.2% (the highest in Europe) would increase average LE by 1.2 LYs and total LE for annual incident cases in the Netherlands by >1800 LYs. Conclusions.Efforts to increase early living-donor RTx could potentially substantially increase LE for patients starting RRT, especially in younger patients.

Immunological aspects of allogeneic and autologous mesenchymal stem cell therapies (Article)

2011-12-01T00:00:00Z

Mesenchymal stem cells (MSCs) have potential for therapeutic application as an immunomodulatory and regenerative agent. The immunogenicity and survival of MSCs after infusion are, however, not clear and evidence suggests that allogeneic but also autologous MSCs disappear rapidly after infusion. This may be associated with the susceptibility of MSCs to lysis by natural killer (NK) cells, possibly a result of culture-induced stress. In the present study we examined whether NK cell-mediated lysis of MSCs could be inhibited by immunosuppressive drugs. Human MSCs were isolated from adipose tissue and expanded in culture. Peripheral blood mononuclear cells were activated with interleukin (IL)-2 (200U/ml) and IL-15 (10ng/ml) for 7 days. CD3-CD16+CD56+NK cells were then isolated by fluorescence-activated cell sorting and added to europium-labeled MSCs for 4hr in the presence or absence of immunosuppressive drugs. Lysis of MSCs was determined by spectrophotometric measurement of europium release. Nonactivated NK cells were not capable of lysing MSCs. Cytokine-activated NK cells showed upregulated levels of granzyme B and perforin and efficiently lysed allogeneic and autologous MSCs. Addition of tacrolimus, rapamycin or sotrastaurin to the lysis assay did not inhibit MSC killing. Furthermore, preincubation of activated NK cells with the immunosuppressive drugs for 24hr before exposure to MSCs had no effect on MSC lysis. Last, addition of the immunosuppressants before and during the activation of NK cells, reduced NK cell numbers but did not affect their capacity to lyse MSCs. We conclude that the immunosuppressive drugs tacrolimus, rapamycin, and sotrastaurin are not capable of inhibiting the lysis of allogeneic and autologous MSCs by activated NK cells. Other approaches to controlling lysis of MSCs should be investigated, as controlling lysis may determine the efficacy of MSC therapy.

ATP-binding cassette transporters as pharmacogenetic biomarkers for kidney transplantation (Article)

2011-10-27T00:00:00Z

Immunosuppressive drugs used in organ transplantation are highly effective in preventing acute rejection. However, the clinical use of these drugs is complicated by the fact that they display highly variable pharmacokinetics and pharmacodynamics between individual patients. The influence of genetic variation on the interindividual variability in immunosuppressive drug disposition, efficacy, and toxicity has been explored in recent years. The polymorphically-expressed ATP-binding cassette (ABC) transporter proteins, in particular ABCB1 and ABCC2, have been investigated extensively because they play an important role in the absorption, distribution and elimination of many immunosuppressive drugs in use today. From these studies it can be concluded that polymorphisms in ABCB1 and ABCC2 have no consistent effect on immunosuppressant pharmacokinetics and toxicity although polymorphisms in ABCB1 appear to be related to the risk of developing calcineurin inhibitor-related nephrotoxicity. However, the latter needs to be replicated before an individual's ABCB1 genotype can become a useful marker that is applied in clinical practice. Future studies evaluating the influence of ABC transporter gene polymorphisms should explore the relationship with intracellular rather than systemic drug concentrations further in well-designed clinical studies. Until then, single-nucleotide polymorphisms in ABC transporter genes are not suitable to act as biomarkers for solid organ transplantation.

Use of stenting in living donor kidney transplantation: Does it reduce vesicoureteral complications? (Article)

2011-06-01T00:00:00Z

The risk of urologic complications after kidney transplantation is 0% to 30%. We studied the impact of prophylactic stent placement during transplantation by assessing the necessity for a percutaneous nephrostomy (PCN) after living kidney transplantation. From January 2003 to December 2007, 342 living donor kidney transplantations were performed. Intra- and postoperative data were collected retrospectively from 285 patients with stent and 57 without. Baseline characteristics were not significantly different between groups, except for the number of previous transplantations: 31 (11%) patients with versus 16 (28%) without stent had a history of >1 transplantation (P < .001). From patients with PCN, 55 (87%) patients in the stented group received a PCN <3 months versus 11 (100%) in the nonstented group (P = .71). The reoperation rate for urologic complications was similar in both groups (3% (stented) versus 5% (nonstented; P = .43). In multivariate analysis, risk for PCN was similar in both groups (odds ratio 1.21, 95% confidence interval 0.52.5). Recipient survival was not significantly different. One- and 3-year death-censored graft survival was not significantly different between stented (89% and 84%) and nonstented group (90% and 85%, P = .71 and P = .96). Ureteral stent insertion is not associated with a reduced rate of PCN placement in living donor kidney transplantation.

CYP3A5 genotype is not related to the intrapatient variability of tacrolimus clearance (Article)

2011-06-01T00:00:00Z

Background: The risk of long-term chronic allograft nephropathy and graft loss after kidney transplantation is increased in patients with a high intrapatient variability of tacrolimus (Tac) clearance. Methods: To test whether this intrapatient variability is associated with an individual's CYP3A5 genotype, we measured the intrapatient variability in Tac clearance in a cohort of 208 kidney transplant recipients treated with Tac and mycophenolate mofetil. Results: Tac dose requirement was significantly higher in patients expressing CYP3A5. However, intraindividual variability of Tac clearance was not related to CYP3A5 genotype. Conclusions: Intraindividual variability in Tac clearance is not related to CYP3A5 genotype. Other factors, including patient adherence, may explain the variability in Tac clearance within an individual patient over time. Copyright

Justification for a home-based education programme for kidney patients and their social network prior to initiation of renal replacement therapy (Article)

2011-05-30T00:00:00Z

In this article, an ethical analysis of an educational programme on renal replacement therapy options for patients and their social network is presented. The two main spearheads of this approach are: (1) offering an educational programme on all renal replacement therapy options ahead of treatment requirement and (2) a homebased approach involving the family and friends of the patient. Arguments are offered for the ethical justification of this approach by considering the viewpoint of the various stakeholders involved. Finally, reflecting on these ethical considerations, essential conditions for carrying out such a programme are outlined. The goal is to develop an ethically justified and responsible educational programme.

New classification of ELPAT for living organ donation (Article)

2011-05-15T00:00:00Z

In the literature, varying terminology for living organ donation can be found. However, there seems to be a need for a new classification to avoid confusion. Therefore, we assessed existing terminology in the light of current living organ donation practices and suggest a more straightforward classification. We propose to concentrate on the degree of specificity with which donors identify intended recipients and to subsequently verify whether the donation to these recipients occurs directly or indirectly. According to this approach, one could distinguish between "specified" and "unspecified" donation. Within specified donation, a distinction can be made between "direct" and "indirect" donation.

Attitudes towards medication non-adherence in elderly kidney transplant patients: A Q methodology study (Article)

2011-05-01T00:00:00Z

Background. Non-adherence to the post-transplant regime is a common problem in kidney transplant patients and may lead to rejection or even graft failure. This study investigated attitudes towards the post-transplant regime of immunosuppressive medication among the ever growing population of elderly kidney recipients.Methods. Q methodology was used to explore attitude profiles. Participants (> 65 years) were asked to rank-order opinion statements on issues associated with (non-)adherence. The rankings were subject to by-person factor analysis, and the resulting factors were interpreted and described as attitudes.Results. Twenty-six elderly renal transplant recipients participated in the study. All passed the Mini-Mental State Examination. Two attitude profiles were found: (i) satisfied and easy-going (attitude A), and (ii) reserved and concerned (attitude B). Elderly patients with attitude A want to enjoy the new life following their kidney transplant, are not very concerned about having to recommence dialysis, now and then even forget their regime, and do not really worry about it. Elderly patients with attitude B feel more insecure about their kidney transplant, are fairly concerned over issues like rejection or going back on dialysis, and try to adapt their way of life to the regime. One-third of these elderly patients forget their medication at least once a month, but there was no difference between attitude groups.Conclusions. Attitudes about the post-transplant regime differ among elderly patients, implying different needs for assistance, monitoring and risk of non-adherence to the regime. The proportion of elderly patients who forget their medication is considerable, but may be much higher among those with mild and severe cognitive limitations.

Risk factors associated with encapsulating peritoneal sclerosis in Dutch EPS study (Article)

2011-05-01T00:00:00Z

Objective: Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD) with a multifactorial pathophysiology and possible increasing incidence. The aim of the present study was to evaluate the independent associations of PD duration, age, dialysis fluids, and kidney transplantation with EPS. Methods: A multicenter case-control study was performed in the Netherlands from 1 January 1996 until 1 July 2007. The population comprised 63 patients with EPS and 126 control patients. Control patients were selected from the national registry and were matched for date of PD start. Associations were analyzed using a log linear regression model. Primary outcome was appearance of EPS. Results: Compared with control patients, patients with EPS were younger at the start of PD (34.7 ±15.4 years vs. 51.5± 14.7 years, p < 0.0001). The cumulative period on PD was longer in EPS patients than in control patients (78.7 ± 37.8 months vs. 32.8 ±24 months, p < 0.0001), and the cumulative period on icodextrin was also longer in EPS patients (32.7 ±23.3 months vs. 18.1 ±15.7 months, p = 0.006). Compared with control patients, more EPS patients underwent kidney transplantation (47 vs. 59, p< 0.0001). With regard to the period after transplantation, the yearly probability of EPS increased in the year after transplantation to 7.5% from 1.75%. In multivariate regression analysis, cumulative PD duration, age at PD start, transplantation, time from last transplantation to EPS, calendar time, time on icodextrin, and ultrafiltration failure were independently associated with EPS. Transfer from PD to hemodialysis for reasons other than suspected EPS could not be identified as a risk factor for EPS. Conclusions: Duration of PD, age at PD start, kidney transplantation, time since last transplantation, ultrafiltration failure, and time on icodextrin were associated with a higher risk of EPS.

How does auxiliary liver transplantation regulate alloreactivity in sensitized kidney transplant patients? (Article)

2011-04-27T00:00:00Z

Effect of obesity on the outcome of kidney transplantation: A 20-year follow-up (Article)

2011-04-27T00:00:00Z

Background: Cardiovascular disease is both a major threat to the life expectancy of kidney transplant recipients and an important determinant of late allograft loss. Obesity is an important risk factor for cardiovascular disease. Methods: We investigated the relation between both pretransplant and 1-year posttransplant body mass index (BMI) with patient and renal graft survival in a cohort of 1810 adult patients. Sixty-one percent of all patients were men; median age (interquartile range [IQR]) was 46 years (35-56 years); median (IQR) pretransplant BMI was 23.0 kg/m (20.8-25.6 kg/m); 1 year after transplantation, the median (IQR) BMI had increased 1.6 kg/m (0.3-3.2 kg/m) and median (IQR) follow-up time was 8.3 years (5.3-12.0 years). We categorized BMI as follows: less than or equal to 20, more than 20 to less than or equal to 25 (normal), more than 25 to less than or equal to 30, and more than 30 (obesity) kg/m. Results: Using a Cox proportional hazards model, after adjustment for cardiovascular risk factors, the relative risks (95% confidence intervals) of death and death-censored graft failure during all follow-up for pretransplant obesity compared with normal BMI were 1.22 (0.86-1.74) and 1.34 (1.02-1.77), respectively; for obesity 1 year after transplantation compared with normal BMI, it was 1.39 (1.05-1.86) and 1.39 (1.10-1.74), respectively; and for change in BMI (per 5 kg/m increment) during the first year after transplantation, it was 1.23 (1.01-1.50) and 1.18 (1.01-1.38), respectively. Conclusions: One year posttransplant BMI and BMI increment are more strongly related to death and graft failure than pretransplant BMI among kidney transplant recipients. Patients with BMI more than 30 kg/m compared with a normal BMI have approximately 20% to 40% higher risk for death and graft failure. Copyright 2011 by Lippincott Williams & Wilkins.

Religious attitudes towards living kidney donation among Dutch renal patients (Article)

2011-04-22T00:00:00Z

Terminal kidney patients are faced with lower quality of life, restricted diets and higher morbidity and mortality rates while waiting for deceased donor kidney transplantation. Fortunately, living kidney donation has proven to be a better treatment alternative (e.g. in terms of waiting time and graft survival rates). We observed an inequality in the number of living kidney transplantations performed between the non-European and the European patients in our center. Such inequality has been also observed elsewhere in this field and it has been suggested that this inequality relates to, among other things, attitude differences towards donation based on religious beliefs. In this qualitative research we investigated whether religion might indeed (partly) be the explanation of the inequalities in living donor kidney transplants (LDKT) among non-European patients. Fifty patients participated in focus group discussions and in-depth interviews. The interviews were conducted following the focus group method and analyzed in line with Grounded Theory. The qualitative data analyses were performed in Atlas.ti. We found that religion is not perceived as an obstacle to living donation and that religion actually promotes helping and saving the life of a person. Issues such as integrity of the body were not seen as barriers to LDKT. We observed also that there are still uncertainties and a lack of awareness about the position of religion regarding living organ donation within communities, confusion due to varying interpretations of Holy Scriptures and misconceptions regarding the process of donation. Faith leaders play an important educational role and their opinion is influential. This study has identified modifiable factors which may contribute to the ethnic disparity in our living donation program. We argue that we need to strive for more clarity and awareness regarding the stance of religion on the issue of living donation in the local community. Faith leaders could be key figures in increasing awareness and alleviating uncertainty regarding living donation and transplantation.

Development of the Rotterdam Renal Replacement Knowledge-Test (R3K-T) (Research Report)

2011-04-01T00:00:00Z

Introduction: There is currently a lack of validated or standardized measures to test the level of knowledge among renal patients regarding kidney disease and available treatment options. We conducted a pilot study to develop a questionnaire measuring knowledge of kidney disease, dialysis and transplantation options. The main aim of this study was to develop such an instrument for further use in research and practice. Method: An initial 61 item pool was generating by searching the literature and consulting experts in this area for additional items. This questionnaire was completed by 182 renal disease patients from 4 dialysis centers in the Rotterdam municipality. A factor analysis was conducted using the maximum likelihood factor method followed by direct oblimin rotation to obtain variance explained by each factor. Questions that loaded ≥ .30 on a factor were included. Results: Twenty-seven patients (24%) were in the pre-RRT phase, 60 (54%) were undergoing haemodialysis, 16 (14%) were undergoing peritoneal dialysis, and 9 (8%) had a graft failure. Forty (36%) were female and 72 (64%) were male. Age range 19-87 (median = 59). A factor analysis was conducted to reduce the number of items. This resulted in 30 items consisting of 5 subscales regarding knowledge on: kidney disease (5 items, α = .37), peritoneal dialysis (4 items, α = .73), haemodialysis (4 items, α = .41), kidney transplantation (12 items, α = .86), quality of life (5 items, α = .59). Discussion: This study aimed to develop an instrument with which knowledge of kidney disease and the related treatment options can be reliably measured. This study resulted in a short and easy to administer knowledge questionnaire. We intend to further explore the psychometric properties of this instrument and develop norm scores for the general public and patients at various stages of the disease and treatment. We have also considered translated versions of this questionnaire.

Living kidney donors: Impact of age on long-term safety (Article)

2011-04-01T00:00:00Z

The safety of older live kidney donors, especially the decline in glomerular filtration rate (GFR) after donation, has been debated. In this study we evaluated long-term renal outcome in older live kidney donors. From 1994 to 2006 follow-up data of 539 consecutive live kidney donations were prospectively collected, during yearly visits to the outpatient clinic. Donors were categorized into two groups, based on age: <60 (n = 422) and ≥60 (n = 117). Elderly had lower GFR predonation (80 vs. 96 mL/min respectively, p < 0.001). During median follow-up of 5.5 years, maximum decline in eGFR was 38%± 9% and the percentage maximum decline was not different in both groups. On long-term follow-up, significantly more elderly had an eGFR <60 mL/min (131 (80%) vs. 94 (31%), p < 0.001). However, renal function was stable and no eGFR of less than 30 mL/min was seen. In multivariate analysis higher body mass index (HR 1.09, 95%CI 1.03-1.14) and more HLA mismatches (HR 1.17, 95%CI 1.03-1.34) were significantly correlated with worse graft survival. Donor age did not influence graft survival. After kidney donation decline in eGFR is similar in younger and older donors. As kidney function does not progressively decline, live kidney donation by elderly is considered safe.

Vaccine-induced allo-hla-reactive memory T cells in a kidney transplantation candidate (Article)

2011-03-27T00:00:00Z

Background. Allo-human leukocyte antigen (HLA) reactivity by naturally acquired viral-specific memory T cells is common. However, the effect of successful vaccination on the alloreactive memory T-cell repertoire is unclear. We hypothesized that vaccination could specifically induce allo-HLA-reactive memory T cells. Methods. A varicella-zoster virus (VZV) immediate early 62 (IE62)-specific CD8 memory T-cell clone was single cell sorted from a VZV seronegative renal transplant candidate after response to live attenuated varicella vaccination. To analyze the allo-HLA reactivity, the VZV IE62-specific T-cell clone was tested against HLA-typed target cells and target cells transfected with HLA molecules, in both cytokine production and cytotoxicity assays. Results. The varicella vaccine-induced VZV IE62-specific T-cell clone specifically produced interferon-γ when stimulated with HLA-B*55:01-expressing Epstein-Barr virus-transformed B cells and HLA-B*55:01-transfected K562 cells (single HLA antigen expressing cell line [SALs]) only. The clone also demonstrated specific cytolytic effector function against HLA-B*55:01 SALs and phytohemagglutinin blasts. Cytotoxicity assays using proximal tubular epithelial cell and human umbilical vein endothelial cell targets confirmed the kidney tissue specificity of the allo-HLA-B*55:01 reactivity, and the relevance of the cross-reactivity to clinical kidney transplantation. The results also suggest that molecular mimicry, and not bystander proliferation, is the mechanism underlying vaccine-induced alloreactivity. Conclusions. Varicella vaccination generated a de novo alloreactive kidney cell-specific cytolytic effector memory T cell in a patient awaiting renal transplantation. Vaccination-induced alloreactivity may have important clinical implications, especially for vaccine timing and recipient monitoring.

Posttransplantation encapsulating peritoneal sclerosis contributes significantly to mortality after kidney transplantation (Article)

2011-03-01T00:00:00Z

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD) and may present after kidney transplantation, a condition known as posttransplantation EPS. The prevalence and impact of posttransplantation EPS on survival after kidney transplantation is unknown. From January 1, 1996 until July 1, 2007, 1241 PD patients were transplanted. Thirty-eight cases of posttransplantation EPS (3%) were identified from the Dutch multicenter EPS study. In EPS patients the mean pretransplant dialysis duration was longer than in the controls (71.4 ± 37.5 months vs. 34.7 ± 25.5, p < 0.0001). The majority of EPS cases were observed within the first 2 years after transplantation, but some cases appeared many years after transplantation. Two hundred and one (16.2%) patients died after transplantation, of which 17 were EPS patients. After infection (23.9%), cardiovascular disease (21.9%) and malignancy (10.9%), EPS (8.5%) was the fourth known cause of death after transplantation. Kaplan - Meier analysis showed a significant decreased survival for transplanted patients with posttransplantation EPS compared to transplanted patients without EPS. In conclusion, posttransplantation EPS is rare but carries a high mortality. A prolonged clinical vigilance and a high index of suspicion for the diagnosis are warranted, specifically in PD patients with a relatively long cumulative pretransplant duration of PD. © 2011 The Authors Journal compilation

Tamoxifen is associated with lower mortality of encapsulating peritoneal sclerosis: Results of the Dutch Multicentre EPS Study (Article)

2011-02-01T00:00:00Z

Background. Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD) with an increasing incidence. There is no clear consensus on the treatment of EPS, but anecdotal reports indicate improvement in EPS patients treated with tamoxifen. At present, there is no evidence for the effect of tamoxifen treatment in EPS patients. This study investigates the effect of treatment with tamoxifen on survival in EPS patients.Methods. This study is a retrospective analysis of survival in EPS patients as part of the Dutch multicentre EPS study in the period January 1996 to July 2007. Sixty-three patients with severe EPS were followed up until August 2008. Demographic, patient and PD-related variables of EPS patients were investigated. Patients treated with tamoxifen were compared to patients not treated with tamoxifen. Survival was analysed with multivariate Cox regression analysis.Results. Twenty-four patients were treated with tamoxifen, and 39 were not treated with tamoxifen. The clinical and demographic characteristics were similar for the tamoxifen-treated and non-treated groups. The mortality rate was significantly lower in tamoxifen-treated patients compared to EPS patients not treated with tamoxifen (45.8% vs 74.4%, P = 0.03). Survival in tamoxifen-treated patients, adjusted for calendar time, age, use of corticosteroids, presence of functioning transplantation, use of parental nutrition and centre influences was longer in comparison to not-treated patients (HR 0.39, P = 0.056).Conclusions. Tamoxifen treatment in EPS patients is associated with lower mortality and shows a trend to an increased multivariate-adjusted survival. This supports additional use of tamoxifen to treat patients with severe EPS.

Discontinuation of calcineurin inhibitors treatment allows the development of FOXP3+ regulatory T-cells in patients after kidney transplantation (Article)

2011-01-01T00:00:00Z

This study investigated specific gene expression profiles in patients with donor-specific cytotoxic-hyporesponsiveness, reflected by cytotoxic T-lymphocyte precursor frequency (CTLpf). The effect of calcineurin inhibitor (CNI) withdrawal was studied on markers for cytotoxicity (perforin, granzyme B), apoptosis (Fas,FasL), Th1 and Th2 cytokines (IL-2, IL-10), Th1 and Th2 transcription factors (T-bet, GATA 3), Th17 transcription factor and cytokine (RORγt, IL-17), and for immune regulation/activation (CD25, FOXP3). Peripheral blood samples from renal allograft recipients (n=18) more than twoyr after transplantation with stable renal function were analyzed before and fourmonths after CNI withdrawal. Additionally, systolic and diastolic blood pressure, cholesterol, serum creatinine and proteinuria were evaluated, and no significant differences were measured before and after CNI withdrawal. However, CNIs' discontinuation influenced peripheral gene expression profiles. After CNI withdrawal, the mRNA expression of Granzyme B, Perforin, Fas, FasL, T-bet, GATA3 and CD25 were significantly lower than during CNI treatment. After CNI discontinuation, donor-specific CTLpf decreased, while FOXP3 expression discriminated between detectable and non-detectable donor-specific cytolysis reactivity; FOXP3 transcript values were highest in absence of donor-specific cytotoxicity (p<0.01). Our study shows CNI withdrawal in stable kidney transplant recipients twoyr after transplantation is safe. Moreover, discontinuation of CNIs' treatment allows FOXP3+ regulatory T-cells development, resulting in a significant decrease of anti-donor immune reactivity.

Quiz page January 2011: A kidney transplant patient with rapidly progressive kidney failure and a radiopaque pyelum wall (Article)

2011-01-01T00:00:00Z

Patient survival after the diagnosis of cancer in renal transplant recipients: A nested case-control study (Article)

2010-12-27T00:00:00Z

Introduction. Malignancy is a well-known complication after renal transplantation. We studied the influence of cancer on patient survival in the Dutch renal transplant population in a nested case-controlled analysis. Methods. Between March 1966 and May 2008, 15,227 renal transplantations in 12,805 recipients were registered in the Netherlands Organ Transplant Registry database. Total follow-up was 89,651 person years. We performed an analysis of patient and graft survival both from the day of transplantation and the diagnosis of cancer in recipients with invasive cancer. Recipients without invasive cancer, matched for gender, age, and year of transplantation, served as a control group. For the survival analysis after the diagnosis of cancer, the matched control group consisted of patients with a functioning graft at the moment the index patient was diagnosed with cancer. Results. Cancer had been registered in 908 (7.1%) patients, 630 (69%) of them died with functioning kidney, 510 (81%) because of their malignancy (at 8.2 years after transplantation, median). The median patient survival after transplantation was 11.9 vs. 16.8 years in the study and control group, respectively (P<0.001). The median patient and graft survival after the diagnosis of cancer was 2.1 vs. 8.3 (P<0.001) and 25 vs. 22.4 (P<0.001) years in the study and control group, respectively. Conclusion. Mortality because of cancer is observed at a significantly later time after transplantation compared with mortality because of the other main lethal complications. It significantly affects life expectancy and carries a poor prognosis with a limited survival after diagnosis.

For love or money? Attitudes toward financial incentives among actual living kidney donors (Article)

2010-12-01T00:00:00Z

Due to lengthening waiting lists for kidney transplantation, a debate has emerged as to whether financial incentives should be used to stimulate living kidney donation. In recent surveys among the general public approximately 25% was in favor of financial incentives while the majority was opposed or undecided. In the present study, we investigated the opinion of living kidney donors regarding financial incentives for living kidney donation. We asked 250 living kidney donors whether they, in retrospect, would have wanted a financial reward for their donation. We also investigated whether they were in favor of using financial incentives in a government-controlled system to stimulate living anonymous donation. Additionally, the type of incentive deemed most appropriate was also investigated. In general almost half (46%) of the study population were positive toward introducing financial incentives for living donors. The majority (78%) was not in favor of any kind of reward for themselves as they had donated out of love for the recipient or out of altruistic principles. Remarkably, 60% of the donors were in favor of a financial incentive for individuals donating anonymously. A reduced premium or free health insurance was the preferred incentive. © 2010 The American Society of Transplantation and the American Society of Transplant Surgeons.

Human adipose tissue-derived mesenchymal stem cells induce explosive T-Cell proliferation (Article)

2010-12-01T00:00:00Z

Mesenchymal stem cells (MSCs) inhibit the proliferation of allo-activated lymphocytes. This effect is primarily dependent on the secretion of anti-inflammatory factors by MSCs and is enhanced under inflammatory conditions. MSCs, however, also produce factors that can potentially activate resting immune cells. Full understanding of the behavior of MSCs under inflammatory and noninflammatory conditions is crucial when clinical application of MSCs is considered. Human adipose tissue-derived MSCs were cultured with nonactivated peripheral blood mononuclear cells (PBMCs) and the activation, proliferation, and function of PBMCs were examined. Seven days of coculture with autologous or allogeneic MSCs significantly increased the proliferation of PBMCs (3-fold). This effect was observed in both direct and transwell coculture systems. MSCs cocultured with PBMCs showed increased mRNA expression of the proinflammatory mediators interleukin-6 (IL-6), IL-8, tumor necrosis factor-Î±, the growth factors basic fibroblast growth factor and vascular endothelial growth factor-Î±, and the anti-inflammatory factor indoleamine 2,3-dioxygenase. After removal of MSCs, PBMCs showed a spectacular further increase in proliferation, with a maximum of 25-fold after 7 days. This increase in proliferation was not seen when PBMCs were kept in the presence of MSCs. The proliferating fraction of PBMCs largely consisted of CD4+T-cells with high CD25 expression and the proportion of CD127negFoxP3+regulatory T-cells significantly increased from 5.0% to 8.5% of total CD4+T-cells. The expanded T-cells demonstrated normal responses to mitogen or alloantigen stimulation. The CD25positivefraction of these cells had immunosuppressive capacity. In conclusion, MSCs can stimulate the activation and proliferation of resting T-cells and generate regulatory T-cells. These findings are important when MSCs are applied in the clinic.

A case of primary aldosteronism revealed after renal transplantation (Article)

2010-11-23T00:00:00Z

Background. A 57-year-old woman was referred to a nephrology clinic because of chronic hypokalemia. She had a history of polycystic kidney disease, resistant hypertension, atrial fibrillation, type 2 diabetes, stroke, and end-stage renal disease, and had received a kidney transplant from a deceased donor at the age of 48 years. At presentation, the patient described symptoms of chronic fatigue and muscle aches, but she did not report pareses. Her medications included four antihypertensive agents, glucose-lowering drugs, immunosuppressants, digoxin, a coumarin derivative, and potassium chloride.Investigations. Full history, physical examination, laboratory testing of blood and urine, including aldosterone-torenin ratio, and a saline infusion test.Diagnosis. Primary aldosteronism.Management. Treatment with spironolactone resulted in prompt control of hypertension and hypokalemia, allowing discontinuation of potassium chloride and reduction in antihypertensive medication.

Preeclampsia is associated with increased cytotoxic T-cell capacity to paternal antigens (Article)

2010-11-01T00:00:00Z

Objective: During an uncomplicated pregnancy the conceptus is a semiallogeneic entity in which rejection is prevented by suppression of the maternal immune system. We hypothesized that this suppression is disturbed in patients with preeclampsia and that a maternal immune response to fetal (foreign/paternal) antigens in the fetal-maternal interface may be responsible for local inflammation, with subsequent endothelial dysfunction and systemic disease. Study design: Blood samples were obtained from 14 women with preeclampsia (cases), 14 gestational-age and parity-matched women with uncomplicated pregnancies (controls), and their partners. We determined the partner-specific cytotoxic T-lymphocyte precursor frequency (CTLpf) and the CTLpf directed to unrelated partners with uncomplicated pregnancies. We measured the CTLpf in peripheral blood mononuclear cells (PBMCs) from cases and controls using limited-dilution assays. In addition, proliferation was tested in a mixed-lymphocyte culture (MLR). Results: The partner-specific CTLpf was significantly higher in cases compared with controls (median, 183 [15-338] vs 67 [9-232] per million PBMCs, P = .02). In contrast, in women with uncomplicated pregnancies, the partner-specific CTLpf was down-regulated compared with the CTLpf directed to an unrelated partner who fathered uncomplicated pregnancies (P = .02). No difference was found in partner-specific MLR response between cases and controls. Conclusion: These results suggest that women with preeclampsia have a higher cytotoxic T-cell response to paternal antigens compared with pregnant controls. This insufficiently suppressed immune response may eventually lead to the development of preeclampsia.

The optimal chain length for kidney paired exchanges: An analysis of the Dutch program (Article)

2010-11-01T00:00:00Z

Living donor kidney exchange programs offer incompatible donor-recipient pairs the opportunity to be transplanted. To increase the number of these transplants, we examined in our actual donor-recipient couples how to reach the maximum number of matches by using different chain lengths. We performed 20 match procedures in which we constructed four different chain lengths: two, up to three, up to four and unlimited. The actual inflow and outflow of donor-recipient couples for each run were taken into consideration in this analysis. The total number of matched pairs increased from 148 pairs for only two-way exchanges to 168 for three-way exchanges. When a chain length of 4 was allowed five extra couples could be matched over a period of 5 years. Unlimited chain length did not significantly affect the results. The optimal chain length for living donor kidney exchange programs is 3. Longer chains with their inherent logistic burden do not lead to significantly more transplants.

Long-Term Follow-up of a Randomized Trial Comparing Laparoscopic and Mini-Incision Open Live Donor Nephrectomy (Article)

2010-11-01T00:00:00Z

Long-term physical and psychosocial effects of laparoscopic and open kidney donation are ill defined. We performed long-term follow-up of 100 live kidney donors, who had been randomly assigned to mini-incision open donor nephrectomy (MIDN) or laparoscopic donor nephrectomy (LDN). Data included blood pressure, glomerular filtration rate, quality of life (SF-36), fatigue (MFI-20) and graft survival. After median follow-up of 6 years clinical and laboratory data were available for 47 donors (94%) in both groups; quality of life data for 35 donors (70%) in the MIDN group, and 37 donors (74%) in the LDN group. After 6 years, mean estimated glomerular filtration rates did not significantly differ between MIDN (75 mL/min) and LDN (76 mL/min, p = 0.39). Most dimensions of the SF-36 and MFI-20 did not significantly differ between groups at long-term follow-up, and most scores had returned to baseline. Twelve percent of the donors reported persistent complaints, but no major complications requiring surgical intervention. Five-year death-censored graft survival was 90% for LDN, and 85% for MIDN (p = 0.50). Long-term outcome of live kidney donation is excellent from the perspective of both the donor and the recipient. © 2010 The American Society of Transplantation and the American Society of Transplant Surgeons.

The Jak inhibitor CP-690,550 preserves the function of CD4 +CD25brightFoxP3+ regulatory T cells and inhibits effector T cells (Article)

2010-08-01T00:00:00Z

The Jak inhibitor CP-690,550 inhibits alloreactivity and is currently being investigated for prevention of allograft rejection after transplantation. In this study, we examined the effect of CP-690,550 on IL-2-mediated Jak/STAT5 phosphorylation by CD4+CD25brightFoxP3 +CD127-/low T cells (Treg) and CD4+CD25 neg effector T cells (Teff) in kidney transplant (KTx) patients. Phosphospecific flow cytometry was used to study the effect of CP-690,550 on IL-2-induced intracellular STAT5-phosphorylation. IL-2-induced phosphorylation of STAT5 (P-STAT5) in both Treg and Teff, which was significantly higher for CD4+CD25bright Treg (increased by 71%, mean) than for CD4+CD25neg Teff (increased by 42%). In the presence of 100 ng/mL CP-690,550, a clinically relevant exposure, IL-2-induced P-STAT5 was partially inhibited in CD4+CD25brightTreg (% inhibition; 51%), while almost completely blocked in Teff (%inhibition; 84%, p = 0.03). The IC50 was 2-3 times higher for Treg (104 ng/mL) than for Teff (40 ng/mL, p = 0.02). In the presence of CP-690,550, Treg exhibited additional suppressive activities on the alloactivated proliferation of Teff (56%, mean). In addition, CD4+CD25bright Treg from KTx-patients receiving CP-690,550 vigorously suppressed the proliferation of Teff (87%, mean). Our findings show that CP-690,550 effectively inhibits Teff function but preserves the suppressive activity of CD4+CD25bright regulatory T cells.

High within-patient variability in the clearance of tacrolimus is a risk factor for poor long-term outcome after kidney transplantation (Article)

2010-08-01T00:00:00Z

Background. We hypothesized that a high within-patient variability in clearance of tacrolimus and mycophenolate mofetil (MMF) would put patients at risk for periods of over- or underimmunosuppression and would thus lead to long-term chronic allograft nephropathy and graft loss after transplantation.Methods. From 297 patients transplanted between 1 January 2000 and 31 December 2004, the within-patient variability in clearance was calculated from tacrolimus whole-blood concentrations and mycophenolic acid (MPA) plasma concentrations drawn between 6 and 12 months post-transplantation. As a primary outcome, a composite end point consisting of graft loss, biopsy-proven chronic allograft nephropathy and 'doubling in plasma creatinine concentration in the period between t = 12 months post-transplantation and last follow-up' was used.Results. In the study population of 297 patients, 34 patients reached the primary end point of graft failure. The within-patient variability in the clearance of tacrolimus and three other covariates are significant risk factors for reaching the composite end point of failure [P-values for intraindividual tacrolimus variability = 0.003, biopsy-proven acute rejection (BPAR) = 0.003, recipient age at transplantation = 0.005]. The mean tacrolimus concentration for controls [7.4 (± 2.9) ng/mL] and for failures [6.9 (± 2.5) ng/mL] was similar. Within-patient variability in the clearance of MPA was not related to reaching the composite end point of failure.Conclusions. This study shows a significant relationship between the high within-patient variability in the clearance of tacrolimus, but not for MPA, and long-term graft failure.

Living kidney donation among ethnic minorities: A Dutch qualitative study on attitudes, communication, knowledge and needs of kidney patients (Internal Report)

2010-08-01T00:00:00Z

Background: Terminal kidney patients are faced with lower quality of life during dialysis treatment, restricted diets and high morbidity and mortality rates while waiting for a deceased donor kidney transplantation. Fortunately, living donor kidney transplantation offers an alternative with considerable advantages in terms of waiting time and graft survival rates. Nevertheless, we observed an inequality in the proportion of living kidney transplantations performed between the non-European patients and the European patients in our centre. To date little is known about the factors contributing towards this racial disparity. Previous research from our centre did not find any medical reasons to explain this racial disparity. We believe that non-medical psychosocial and cultural factors predominantly account for this discrepancy. Purpose Focus group discussions and in-depth interviews were conducted in order to gain insight in the attitudes, (non-)communication and knowledge of our non-European patients (compared to European patients) regarding living donor kidney transplantation (LDKT). Additionally, we investigated their attitudes towards professional support in finding an eligible living donor. Methods: The interviews were held in line with the focus group method and analyzed according to the grounded theory. The interviews were focused on six main topics (kidney transplantation, living kidney donation, communication, information, knowledge and intervention needs). European patients were included as a comparison group. The qualitative data analyses were performed in Atlas.ti. Results:We found nearly all our patient to be in favour of a living kidney transplantation (96%). However multiple prohibiting intertwined factors play a role when actually considering a living donor. We found four major barriers to the living donor transplantation process in our non-European patients: 1) not (so easily) comprehensible non-patient-centered information 2) cognitions and emotions (based on fears, concerns and misconceptions) 3) a state of basically non-communication with the potential donor(s) on this issue (as a consequence of personal and cultural beliefs) 4) and social influences. We also found some similar factors playing a role in the donation course of our European patients without a living donor. Finally, our patients held a welcoming attitude towards an intervention aimed at assisting them getting though the living donation program. Discussion: This study has identified several modifiable determinants underlying racial disparity in our living donor kidney transplantation program and investigated patients’ attitude towards two interventions aimed at alleviating this inequality. We realize that our list of barriers may not be thorough enough and surely more is to be said on this topic, the findings offer possible targets for intervention. In accordance with our patients’ preference, we argue that a home-based education best suits the complexity of issues and patients’ personal needs.

Advancement of mesenchymal stem cell therapy in solid organ transplantation (MISOT) (Article)

2010-07-27T00:00:00Z

There is evolving interest in the use of mesenchymal stem cells (MSC) in solid organ transplantation. Pre-clinical transplantation models show efficacy of MSC in prolonging graft survival and a number of clinical studies are planned or underway. At a recent meeting of the MISOT consortium (MSC In Solid Organ Transplantation) the advances of these studies were evaluated and mechanisms underlying the potential effects of MSC discussed. Continued discussion is required for definition of safety and eventually efficacy endpoints for MSC therapy in solid organ transplantation.

Encouraging psychological outcomes after altruistic donation to a stranger (Article)

2010-06-01T00:00:00Z

In a growing number of transplant centers worldwide, altruistic donors are accepted to anonymously donate a kidney to a stranger. An important hesitation to expand these transplantation programs is the fear of evoking psychological distress in the altruistic donor after donation. To what extent this fear is justified has not yet been systematically investigated. In this study, 24 altruistic donors were interviewed on average 2 years after donation. Lifetime mental health history, current psychological complaints, satisfaction with and impact of the donation on well-being, motives for donation, communication with recipient and donation experience were assessed. Altruistic donors report a considerable positive impact of donation on psychological well-being, whereas negative impact was limited. Satisfaction with donation was very high. Although a history of a psychiatric diagnosis was ascertained in almost half of the donors, psychological complaints before and after donation were comparable to national average norm scores. Motives for donation were genuine and the experience of donation generally conformed to their expectations. In conclusion, living kidney donation to a stranger does not appear to exacerbate psychological complaints. Moreover, altruistic donors report considerable satisfaction and personal benefit. The exceptional gift of altruistic donors can contribute toward solving the current organ shortage issue.

Ethnically diverse populations and their participation in living kidney donation programs (Article)

2010-05-27T00:00:00Z

Background: The number of living donor kidney transplantations increases steeply in Europeans, whereas the non-Europeans are dependent on deceased donor transplantations. We wondered whether a low attendance or a high decline of potential non-European donors could explain this difference. Methods: This retrospective study includes all 1059 potential living kidney donors who attended our pretransplant clinic between 2000 and 2007. Potential donors were divided according to eight countries of origin: African, Dutch Antillean, European, Indonesian, Moroccan, Surinamese, Turkish, and various countries. In addition to direct living donation, alternative living donation programs are operational in our center: kidney exchange, domino paired, ABO incompatible, and anonymous donation. Results: European donors predominated in both the potential (79%) and the actual donor populations (85%). Actual donors comprised 39% of non-European and 59% of the European potential donors (P<0.001). Participation in alternative donation programs is significantly less among non-European donors in comparison with European donors (3.6% vs. 12.6%, P<0.001). In all non-European populations, genetically related donors predominated, whereas genetically related and unrelated donors were equally represented in the European potential donor population (P<0.001). Partners were under-represented in all non-European populations (P<0.001). The attitude and behavior of non-Europeans with the longest duration of stay in the Netherlands were closest to that of the Europeans. The population with the shortest stay differed the most. This could possibly be attributed to integration. Conclusion: There are less non-European donors than expected based on the population composition. Living donor characteristics are different between Europeans and non-Europeans. The reasons for the difference deserve investigation. Copyright

Hand-assisted retroperitoneoscopic versus standard laparoscopic donor nephrectomy: HARP-trial (Article)

2010-04-28T00:00:00Z

Background. Transplantation is the only treatment offering long-term benefit to patients with chronic kidney failure. Live donor nephrectomy is performed on healthy individuals who do not receive direct therapeutic benefit of the procedure themselves. In order to guarantee the donor's safety, it is important to optimise the surgical approach. Recently we demonstrated the benefit of laparoscopic nephrectomy experienced by the donor. However, this method is characterised by higher in hospital costs, longer operating times and it requires a well-trained surgeon. The hand-assisted retroperitoneoscopic technique may be an alternative to a complete laparoscopic, transperitoneal approach. The peritoneum remains intact and the risk of visceral injuries is reduced. Hand-assistance results in a faster procedure and a significantly reduced operating time. The feasibility of this method has been demonstrated recently, but as to date there are no data available advocating the use of one technique above the other. Methods/design. The HARP-trial is a multi-centre randomised controlled, single-blind trial. The study compares the hand-assisted retroperitoneoscopic approach with standard laparoscopic donor nephrectomy. The objective is to determine the best approach for live donor nephrectomy to optimise donor's safety and comfort while reducing donation related costs. Discussion. This study will contribute to the evidence on any benefits of hand-assisted retroperitoneoscopic versus standard laparoscopic donor nephrectomy. Trial Registration. Dutch Trial Register NTR1433.

Optimizing left-sided live kidney donation: Hand-assisted retroperitoneoscopic as alternative to standard laparoscopic donor nephrectomy (Article)

2010-04-01T00:00:00Z

Laparoscopic donor nephrectomy (LDN) is less traumatic and painful than the open approach, with shorter convalescence time. Hand-assisted retroperitoneoscopic (HARP) donor nephrectomy may have benefits, particularly in left-sided nephrectomy, including shorter operation and warm-ischemia time (WIT) and improved safety. We evaluated outcomes of HARP alongside LDN. From July 2006 to May 2008, 20 left-sided HARP procedures and 40 left-sided LDNs were performed. Intra and postoperative data were prospectively collected and analysis on outcome of both techniques was performed. More female patients underwent HARP compared to LDN (75% vs. 40%, P = 0.017). Other baseline characteristics were not significantly different. Median operation time and WIT were shorter in HARP (180 vs. 225 min, P = 0.002 and 3 vs. 5 min, P = 0.007 respectively). Blood loss did not differ (200 ml vs.150 ml, P = 0.39). Intra and postoperative complication rates for HARP and LDN (respectively 10% vs. 25%, P = 0.17 and 5% vs. 15%, P = 0.25) were not significantly different. During median follow-up of 18 months estimated glomerular filtration rates in donors and recipients and graft- and recipient survival did not differ between groups. Hand-assisted retroperitoneoscopic donor nephrectomy reduces operation and warm ischemia times, and provides at least equal safety. Hand-assisted retroperitoneoscopic may be a valuable alternative for left-sided LDN.

Altruistic donor triggered domino-paired kidney donation for unsuccessful couples from the kidney-exchange program (Article)

2010-04-01T00:00:00Z

Between January 2000 and July 2009, 132 individuals inquired about altruistic kidney donation to strangers. These donors were willing to donate to genetically and emotionally unrelated patients. Some altruistic donors wished to donate to a specific person, but most wished to donate anonymously. In domino-paired donation, the altruistic donor donates to the recipient of an incompatible couple; the donor of that couple (domino-donor) donates to another couple or to the waiting list. In contrast to kidney-exchange donation where bilateral matching of couples is required, recipient and donor matching are unlinked in domino-paired donation. This facilitates matching for unsuccessful couples from the kidney-exchange program where blood type O prevails in recipients and is under-represented in donors. Fifty-one altruistic donors (39%) donated their kidney and 35 domino-donors were involved. There were 29 domino procedures, 24 with 1 altruistic donor and 1 domino-donor, 5 with more domino-donors. Eighty-six transplantations were performed. Donor and recipient blood type distribution in the couples limited allocation to blood type non-O waiting list patients. The success rate of domino-paired donation is dependent on the composition of the pool of incompatible pairs, but it offers opportunities for difficult to match pairs that were unsuccessful in the kidney-exchange program.

Characterization of rabbit antithymocyte globulins-induced CD25+ regulatory T cells from cells of patients with end-stage renal disease (Article)

2010-03-01T00:00:00Z

Background: Rabbit antithymocyte globulins (rATGs) are known to convert CD4CD25FoxP3 T cells from healthy individuals to CD4CD25FoxP3 T cells. In this study, we investigated the effect of rATG on the induction of regulatory T cells (Tregs) from blood cells of patients with end-stage renal disease who are candidates for transplantation and rATG-induction therapy. The induced Tregs were analyzed and compared with naturally occurring CD4CD25FoxP3T cells. Methods: The CD25 T cells of pretransplant patients (n=7) and healthy controls (n=4) were stimulated with rATG or control rabbit immunoglobulins for 24 hr. The phenotype of induced Tregs was examined by flow cytometry, and their function was studied in the conventional suppression assay. Further characterization was performed by mRNA analyses. Results: After 24 hr, the percentage of CD4CD25FoxP3CD127 T cells and CD8CD25FoxP3CD127 T cells became higher in the rATG-treated samples compared with the rabbit immunoglobulin-treated samples (P<0.01). The rATG-induced CD25T cells, whether CD4 or CD8 inhibited the allogeneic responses of CD25 effector T cells as vigorously as natural CD25T cells. However, the proportion of FoxP3 within the top 2% rATG-induced CD4CD25T-cells was lower than within the natural CD4CD25T-cells (11%±2% vs. 95%±5%, P<0.01). The mRNA-expression levels of interleukin-27, interleukin-10, interferon-γ, perforin, and granzyme B were markedly higher compared with natural CD25T-cells (all P=0.03), whereas CTLA4 (P=0.03), transforming growth factor-β (P=0.02), and RORγt (P=0.04) were lower. Conclusion: rATG allows the induction of Tregs from patient peripheral blood mononuclear cell in vitro. In comparison with natural Tregs, the rATG-induced Tregs are phenotypically distinct but have similar regulatory activities. rATG may beneficially contribute to the mechanisms that control alloreactivity.

Cell contact interaction between adipose-derived stromal cells and allo-activated T lymphocytes (Article)

2009-12-01T00:00:00Z

Mesenchymal stromal cells regulate immune cell function via the secretion of soluble factors. Cell membrane interactions between these cell types may play an additional role. Here, we demonstrate that subpopulations of allo-activated T cells are capable of binding to human adipose-derived stromal cells (ASC). The bound T-cell population contained CD8+T cells and was enriched for CD4-CD8-T cells, whereas the proportion of CD4+T cells was decreased compared with the non-bound T-cell population. Bound CD4+T cells had high proliferative activity and increased CD25 and FoxP3 expression. However, they also expressed CD127, excluding regulatory T-cell function. In CD8+T cells, IL-2 sensitivity, as determined by the analysis of phosphorylated STAT5, was lower in the presence of ASC and even lower in bound cells. In contrast, IL-2-induced phosphorylated STAT5 levels were higher in bound CD4+T cells than in non-bound CD4+T cells. Additionally, pro-proliferative TGF-β signalling via endoglin and SMAD1/5/8 phosphorylation was detected in bound CD4+T cells. Even after prolonged co-culture with ASC, the activated phenotype of bound CD4+T cells persisted. In conclusion, these results demonstrate that the binding of lymphocytes to ASC represents an immunomodulatory mechanism in which CD8+T cells are inhibited in their responsiveness to pro-inflammatory stimuli and reactive CD4+T cells are depleted from the immune response.

CMV seropositivity determines epoetin dose and hemoglobin levels in patients with CKD (Article)

2009-12-01T00:00:00Z

Cytomegalovirus (CMV)-seropositive patients with ESRD may have more CD4+T cells lacking the co-stimulatory molecule CD28 (CD4+CD28null) than CMV-seronegative patients. Increased numbers of CD28null T cells associates with epoetin nonresponsiveness in patients with ESRD, but whether expansion of CD4+CD28null T cells in CMV-seropositive patients associates with demand for epoetin is unknown. In a cohort of 129 stable patients with ESRD, CMV seropositivity significantly associated with a lower hemoglobin level in predialysis patients (12.5 versus 11.5 g/dl; P < 0.02). CMV seropositivity did not associate with average hemoglobin level in hemodialysis patients, but CMV-seropositive patients required significantly more epoetin (median 12,000 versus 6300 U/wk; P = 0.02). Multivariate linear regression analysis identified CMV seropositivity as the only variable significantly associated with hemoglobin levels in predialysis patients and epoetin dosages in hemodialysis patients. In CMV-seropositive hemodialysis patients, the number of circulating CD4+CD28null T cells positively correlated with epoetin dosage. These CD4+CD28null T cells were proinflammatory; they were capable of producing large amounts of IFN-γ and TNF-α. In conclusion, expansion of CD4+CD28null T cells in CMV-seropositive patients with ESRD associates with increased demand for epoetin. Copyright

A plea for uniform European definitions for organ donor potential and family refusal rates (Article)

2009-11-01T00:00:00Z

Conversion of potential organ donors to actual donors is negatively influenced by family refusals. Refusal rates differ strongly among countries. Is it possible to compare refusal rates in order to be able to learn from countries with the best practices? We searched in the literature for reviews of donor potential and refusal rates for organ donation in intensive care units. We found 14 articles pertinent to this study. There is an enormous diversity among the performed studies. The definitions of potential organ donors and family refusal differed substantially. We tried to re-calculate the refusal rates. This method failed because of the influence caused by the registered will on donation in the Donor Register. We therefore calculated the total refusal rate. This strategy was also less satisfactory considering possible influence of the legal consent system on the approach of family. Because of lack of uniform definitions, we can conclude that the refusal rates for organ donation can not be used for a sound comparison among countries. To be able to learn from well-performing countries, it is necessary to establish uniform definitions regarding organ donation and registration of all intensive care deaths.

Inosine monophosphate dehydrogenase messenger RNA expression is correlated to clinical outcomes in mycophenolate mofetil-treated kidney transplant patients, whereas inosine monophosphate dehydrogenase activity is not (Article)

2009-10-01T00:00:00Z

Measurement of the pharmacodynamic biomarker inosine monophosphate dehydrogenase (IMPDH) activity in renal transplant recipients has been proposed to reflect the biological effect better than using pharmacokinetic parameters to monitor mycophenolate mofetil therapy. The IMPDH assays are however labor intensive and this complicates implementation into patient care. Quantification of IMPDH messenger RNA (mRNA) could form an attractive alternative. This study was designed to correlate IMPDH mRNA levels with IMPDH activity and clinical outcome in renal transplant recipients. From a cohort of 101 renal transplant patients, blood samples were drawn pre transplantation and at 4 times after transplantation. IMPDH activity, IMPDH type 1 and type 2 mRNA levels, and mycophenolic acid concentrations were measured and correlated to clinical outcomes. No correlation was found between IMPDH type 1 and type 2 mRNA levels and IMPDH activity in pre- and posttransplant samples. A significant increase in IMPDH mRNA levels was found between day 6 and day 140 after transplantation. IMPDH type 1 and type 2 mRNA levels before transplant showed a trend toward statistically significant higher levels in patients with an acute rejection (P = 0.052 and P = 0.058). After transplant, the IMPDH type 1 and type 2 mRNA levels were significantly lower in patients with an acute rejection (P = 0.026 and P = 0.007). We conclude that IMPDH mRNA levels do not correlate with IMPDH activity but are nevertheless correlated with acute rejections. Furthermore, although the regulation of the expression of the 2 isoforms is presumed to be different, in this study, the changes in the expression of type 1 mRNA closely paralleled those of type 2.

Polymorphisms of the glucocorticoid receptor and avascular necrosis of the femoral heads after treatment with corticosteroids (Article)

2009-10-01T00:00:00Z

A female patient developed avascular necrosis of the femoral heads after receiving low doses of glucocorticosteroids (GC) for 3 months. Genotyping of the GC receptor (GR) showed that she was heterozygous for the Bcl-1 allele and heterozygous for the N363S allele. Interestingly, these GR variants are both associated with higher sensitivity to glucocorticoids. It is not known whether the GR gene polymorphisms are causally related to osteonecrosis. However, the presence of these GR variants, as a combination present in only 1 of the normal Caucasian population, seems suggestive. Studies are warranted to investigate the importance of polymorphisms related to GC sensitivity.

Monitoring of the immunomodulatory effect of CP-690,550 by analysis of the JAK/STAT pathway in kidney transplant patients (Article)

2009-10-01T00:00:00Z

BACKGROUND.: The small molecule drug CP-690,550 inhibits Janus kinase 3 at nanomolar concentrations and has recently been shown to prevent allograft rejection in rodents and nonhuman primates. METHODS.: As part of a phase 1 clinical trial, we investigated the effect of CP-690,550 after 29 days of 30 mg twice daily treatment at the cellular level in eight kidney transplant patients by studying ex vivo phosphorylation of STAT5 (P-STAT5), the key substrate of JAK3. RESULTS.: As determined by quantitative fluorescent western blotting, interleukin-2-induced P-STAT5 in YT cells was reduced by a median of 73% (P<0.01) in the presence of serum collected on day 29 compared with pretreatment baseline. When evaluated by phosphospecific flow cytometry, CP-690,550 also reduced interleukin-2-induced P-STAT5 in CD3 (median 20%; P<0.05), CD3CD4 (median 37%; P<0.05), and CD3CD8 (median 34%; P<0.01) populations in patient-derived peripheral blood mononuclear cells. At the functional level, the inhibitory effect of CP-690,550 was confirmed by determining the expression of several STAT5 targets genes. CONCLUSION.: Analysis of P-STAT5 may, therefore, be used to determine the immunomodulatory effect of CP-690,550 at the cellular level in transplant patients.

Regulatory T cells in alloreactivity after clinical heart transplantation (Article)

2009-10-01T00:00:00Z

Purpose of review As the knowledge of CD4+CD25bright+FoxP3+regulatory T cells in experimental transplant models grows, we need to understand how and to what extent these suppressor cells regulate donor-directed immune events in the transplantation clinic. This review focuses on the function of regulatory T cells in the peripheral blood and the transplanted organ of patients after heart transplantation during immunological quiescence and rejection. Recent findings Here, we present data that peripheral CD4+CD25bright+FoxP3+T cells of heart transplant patients who experience acute rejection have inadequate immune regulatory function in vitro compared with those of nonrejecting patients. During rejection, potent donor-specific T-cell suppressors are present in the transplanted organ. Summary The studies in transplant patients' show that the function of CD4+CD25bright+FoxP3+regulatory T cells in alloimmunity is to inhibit the activation of effector T cells, to prevent rejection, and to control the antidonor response at the graft itself at later stages of immune reactivity.

Monotherapy rapamycin allows an increase of CD4+ CD25 bright+ FoxP3+ T cells in renal recipients (Article)

2009-09-01T00:00:00Z

CD4+ CD25bright+ FoxP3+ regulatory T cells (Tregs) may control donor-specific allogeneic responses in kidney transplant recipients. Recent evidence demonstrated that three phenotypical Treg-subsets, naive (CCR7+CD45RO-), central-memory (CCR7 +CD45RO+) and effector-memory (CCR7-CD45RO +), are essential for the development and function of antigen-specific suppression in the lymphoid and peripheral tissues. Also, it has been appreciated that Tregs are affected by immunosuppressive agents. In clinical practice, however, the effect of a single drug remains to be determined. Therefore, we analyzed the effect of several immunosuppressive agents on the number, phenotype and function of peripheral Tregs from 46 stable kidney transplant recipients. These patients were converted to monotherapy with tacrolimus (n = 15), rapamycin (n = 17) or mycophenolate mofetil (n = 14). Blood was obtained at inclusion and 6 months thereafter. The number of Tregs increased significantly in patients on monotherapy with rapamycin (P < 0.001), which was caused by increased numbers of Tregs with a central-memory and an effector-memory phenotype (both P < 0.05). At 6 months after conversion, however, the suppressive function of Tregs did not significantly change in co-cultures stimulated with donor-Ag. Therefore, monotherapy with rapamycin allows the signals that are needed to increase the number of functional Tregs with a memory phenotype, thereby enhancing the potential capacity to regulate donor-specific responses in the lymphoid and the peripheral tissues.

Non-HLA T-cell reactivity during the first year after HLA-identical living-related kidney transplantation (Article)

2009-09-01T00:00:00Z

Background: It has been reported that donor-reactive T-cell responses may decrease during the first year after HLA-mismatched organ transplantation. We wondered whether donor-reactive T-cell responses directed to minor histocompatibility antigens (mHAgs) or other non-HLA antigens also decrease after HLA-identical living-related (LR) kidney transplantation. Methods: We studied donor-reactive T-cell responses by IFN-γ and granzyme B (GrB) Elispot assays in 15 HLA-identical LR kidney transplant recipients before, six months and one yr after transplantation. Third-party reactivity was used as control. Patient and donor peripheral blood mononuclear cells were typed for 11 known mHAgs. Results: During the study period, 60% and 36% of the patients demonstrated donor-reactive IFN-γ and GrB producing cells (pc), respectively. The number of donor-reactive IFN-γ and GrB pc was significantly lower than the number of third-party reactive IFN-γ and GrB pc. After transplantation, donor-reactivity and third-party reactivity were comparable to pre-transplant values. No relation was found in mHAg mismatches between donor and recipient and donor-reactive T-cell response. Conclusions: Donor-reactivity could be detected before and after HLA-identical LR kidney transplantation, but was not related with the number of mHAg mismatches, and did not decrease after transplantation.

Successful expansion of the living donor pool by alternative living donation programs (Article)

2009-09-01T00:00:00Z

Between January 2000 and December 2007, 786 potential recipients and 1059 potential donors attended our pretransplant unit with the request for a living-donor renal transplant procedure. The recipients brought one potential donor in 77.2% and two or more donors in 22.8% of cases. In the regular living donor program, a compatible donor was found for 467 recipients. Without considering alternative donation, 579 donors would have been refused. Alternative living donation programs led to 114 compatible combinations: kidney-exchange program (35), ABO-incompatible donation (25), anonymous donation (37) and domino-paired anonymous donation (17). Together, the 114 alternative program donations and the 467 regular living donations led to 581 living donor transplantations (24.4% increase). Eventually for 54.9% (581/1059) of our donors, a compatible combination was found. Donor-recipient incompatibility comprised 19.4% (89/458) in the final refused population, which is 8.8% of the potential donor-recipient couples. Without considering alternative donation, 30.1% (174/579) of the refused donors would have been refused on incompatibility and 6.4% (37/579) because they were anonymous. This is 20% of the potential donor population (211/1059). The implementation of alternative living donation programs led to a significant increase in the number of transplantations, while transplantations via the direct donation program steadily increased.

Interpatient variability in IMPDH activity in MMF-treated renal transplant patients is correlated with IMPDH type II 3757T>C polymorphism (Article)

2009-08-01T00:00:00Z

OBJECTIVES: The active metabolite of mycophenolate mofetil (MMF), mycophenolic acid, inhibits the activity of the target enzyme inosine monophosphate dehydrogenase (IMPDH). The aim of this study was to correlate eight different single nucleotide polymorphisms of the IMPDH type II gene to the activity of the IMPDH enzyme to explain between-patient differences in IMPDH activity. METHODS AND RESULTS: In a prospective study, we measured IMPDH activity, mycophenolic acid plasma concentrations, and eight polymorphisms of IMPDH type II in de novo kidney transplant recipients, 6 days posttransplantation while on MMF treatment. Polymorphisms in the IMPDH type II gene were only observed for the IMPDH type II 3757T>C (rs11706052) single nucleotide polymorphism. Ten of 101 patients (10%) were heterozygous and two of 101 patients (2%) homozygous for IMPDH type II 3757T>C. The allele frequency was 6.9%. The IMPDH activity over 12h (AUCact) was 49% higher for patients with an IMPDH type II 3757C variant [n=12 vs. n=68; 336 (95% confidence interval: 216-521) vs. 227 (95% confidence interval: 198-260)hμmol/s/mol adenosine monophosphate; P=0.04]. The IMPDH activity measured before transplantation (Actpre-Tx) was not significantly different between IMPDH type II 3757TT wild-type and variant carrier patients (P=0.99). CONCLUSION: We report that the IMPDH type II 3757T>C polymorphism is associated with an increased IMPDH activity in MMF-treated renal transplant patients. This polymorphism explains 8.0% of the interpatient variability in IMPDH activity.

Pre-kidney-transplant blood transfusions do not improve transplantation outcome: A Dutch national study (Article)

2009-08-01T00:00:00Z

Background. Female renal transplant candidates are prone to be sensitized by prior pregnancies, and undetected historical sensitization might decrease transplantation outcome. Hypothesis of our study was that pre-transplant blood transfusions (PTFs) can elucidate historical sensitization and that the avoidance of the associated antigens can improve transplantation outcome.Methods. Data from all female non-immunized renal transplant candidates who received a random PTF (rPTF) (n = 620), matched PTF (mPTF) (one HLA-A and B and one HLA-DR match) (n = 86) or donor-specific blood transfusion (DST) (n = 100) between 1996 and 2006 were collected. Complement-dependent cytoxicity was used to detect anti-HLA antibodies. Sensitization and transplantation outcomes after a PTF were analyzed. Non-immunized female renal transplant recipients who did not receive a PTF were used as the control group.Results. In 165 patients, anti-HLA antibodies (IgG) were detected after the PTF. Both historical and primary sensitizations were found. A DST induced donor-specific anti-HLA antibodies in 25 of the DST recipients. Our policy did not improve transplantation outcome in recipients of a kidney from a deceased donor (n = 368) or in recipients of a living donor DST (n = 49) and mPTF (n = 66).Conclusions. A PTF did elucidate historical sensitization but induce primary sensitization as well. No beneficial effect of PTFs on transplantation outcome was found, and PTFs with the intention to detect historical sensitization are therefore not suggested.

Regional kidney allocation based only on full hla-dr compatibility is not feasible (Article)

2009-08-01T00:00:00Z

Clinical rejection and persistent immune regulation in kidney transplant patients (Article)

2009-07-01T00:00:00Z

We evaluated whether the regulatory function of CD4+CD25high+FoxP3+T-cells from patients on tacrolimus and mycophenolate mofetil (MMF) is affected by preceding steroid and anti-CD25 mAb induction therapy and whether this function is associated with rejection after kidney transplantation. Kidney recipients (N = 15) were randomized to receive either anti-CD25 mAb induction (i.e., daclizumab) or steroids for 4 months. We analyzed the presence and suppressive activity of CD4+CD25high+FoxP3+peripheral T-cells in samples obtained at pre and 4-6 months after transplantation. Anti-CD25 mAb therapy and treatment with steroids did not significantly affect protein expression of FoxP3. However, at the functional level, significant differences were found in the regulatory activities of CD4+CD25high+T-cells from the anti-CD25 group vs those from the steroid group. At 4-6 months after transplantation, the regulatory activities of CD4+CD25high+T-cells were comparable to those before anti-CD25 mAb therapy; 49 ± 13% (mean ± SEM) vs 40 ± 14% at a 1:20 ratio (CD25high+:CD25-/dim), respectively. In contrast, the regulatory capacities of CD+D25bright+T-cells from the steroid patient group became significantly impaired. The percentage inhibition of the anti-donor response decreased from 57 ± 12% before transplantation to 12 ± 7% after transplantation (p < 0.01). Five out of 15 patients experienced a rejection episode. At 4-6 months after transplantation, the CD25high+cells from these rejectors (who all received daclizumab induction therapy) had clear regulatory function, while suppression by CD25high+cells from non-rejectors (N = 10) was significantly lower. The percentage inhibition of the anti-donor response was 48 ± 14% (mean ± SEM) vs 10 ± 7%, respectively, p = 0.02. Anti-CD25 mAb induction therapy does not negatively influence the regulatory function of CD4+CD25high+FoxP3+T-cells from kidney transplant recipients on tacrolimus and MMF. The majority of these patients experienced an acute rejection episode, which suggests that immune activation is required for persistent immunoregulatory function.

A Multiplex Bead Array Analysis to Monitor Donor-Specific Cytokine Responses After Withdrawal of Immunosuppression in HLA-Identical living Related Kidney Transplant Patients (Article)

2009-06-01T00:00:00Z

Immune reactivity after HLA-identical living related (LR) kidney transplantation can be caused by minor histocompatibility antigen and non-HLA antigen mismatches between donor and recipient. In our center, HLA-identical LR kidney transplant recipients receive azathioprine (AZA) or mycophenolate mofetil (MMF) in combination with corticosteroids for 1 year after transplantation. Thereafter, AZA or MMF was withdrawn, and the patients were treated with steroid monotherapy as maintenance therapy. We questioned whether withdrawal of AZA or MMF affected the donor-specific lymphocyte proliferation and cytokine production. Donor and third-party T-cell reactivities were determined by mixed lymphocyte reactions and by cytokine production using multiplex bead array technique. The donor and third-party proliferative capacities were not affected after withdrawal of AZA or MMF. Thirteen of 17 cytokines were detected by the multiplex bead array technique. No differences were observed after third-party induced cytokine production after withdrawal of AZA or MMF. However, production of donor-specific interferon-γ and macrophage inflammatory protein-1β increased after discontinuation of AZA or MMF, but no clinically relevant acute rejection was observed. In conclusion, after HLA-identical LR kidney transplantation, donor-specific cytokine responses can be found when AZA or MMF therapy is discontinued. The clinical relevance of this phenomenon is still not evident.

End-stage renal failure and regulatory activities of CD4 +CD25bright+FoxP3+ T-cells (Article)

2009-06-01T00:00:00Z

Background. The defensive immune system in patients with end-stage renal failure is impaired at multiple levels. This state of immune incompetence is associated with continuous activation of the immune system. An additional explanation for this state of activation may be the disturbed function of CD4+CD25bright+FoxP3+regulatory T-cells.Methods. The phenotype and function of peripheral regulatory T-cells from patients with end-stage renal failure (N = 80) and healthy controls (N = 17) was studied by flow cytometry, RT-PCR and mixed lymphocyte reaction. Patients were on haemodialysis (N = 40), peritoneal dialysis (N = 26) or not treated with dialysis yet (N = 14). The latter group had a glomerular filtration rate of <20 mlmin 1.73 m2.Results. The basal IL-2 mRNA level was high in patient-PBMC (P = 0.0002 versus healthy controls). The absolute number of CD4+CD25bright+T-cells was low in patients (P < 0.05 versus healthy controls). Furthermore, proliferation of patient-PBMC upon allogeneic stimulation was impaired (P < 0.0001 versus healthy controls). The regulatory function of CD4+CD25bright+T-cells was determined in the setting of direct allorecognition. First, the effect of depletion of CD25bright+cells from patient-PBMC on proliferation was low. Second, co-culture of CD25bright+cells with CD25negdimcells (1:10 ratio) showed impaired regulatory function (P < 0.001 versus healthy controls), which was especially pronounced in patients on dialysis. The FOXP3 mRNA level was also low upon stimulation (P = 0.0002 versus healthy controls).Conclusions. In line with previous studies, we observed an overactivated but functionally compromised immune system in patients with end-stage renal failure. It now appears that in this setting, regulation by CD4+CD25bright+FoxP3+T-cells is also impaired.

Deficient TNF-α and IFN-γ production correlates with nondetectable donor-specific cytotoxicity after clinical kidney transplantation (Article)

2009-05-27T00:00:00Z

BACKGROUND.: We previously reported that no cytotoxic T-lymphocyte precursor frequencies (CTLpf) were found in 60% of patients on azathioprine or mycophenolate mofetil+Pred long after kidney transplantation. We questioned whether the absence of donor-specific CTLpf was associated with low levels of stimulatory Th1 (tumor necrosis factor [TNF]-α, interferon [IFN]-α) or high levels of regulatory Th2 (interleukin [IL]-4, IL-6, IL-10) cytokines. METHODS.: In this study, peripheral blood monocyte cells (PBMC) were stimulated with irradiated donor cells. After 7 days, cytokine production was determined by cytokine bead array, and CTLpf by limiting dilution assay. RESULTS.: Patients with detectable CTLpf (ĝ‰¥10/10 PBMC) had significantly higher levels of TNF-α (P=0.04) and IFN-α (P=0.02) than patients with nondetectable CTLpf (<10/10 PBMC). Donor-reactive IL-4, IL-6, and IL-10 production was comparable in both patient groups. Additionally, CTLpf was positively correlated with TNF-α (rs=0.54, P=0.0003) and IFN-α (rs=0.64, P<0.0001) production. CONCLUSION.: The absence of donor-specific CTLp after transplantation correlates with low levels of stimulatory cytokines, not with elevated levels of regulatory cytokines.

The effect of rabbit anti-thymocyte globulin induction therapy on regulatory T cells in kidney transplant patients (Article)

2009-05-01T00:00:00Z

Background. Prevention of alloreactivity by rabbit anti-thymocyte globulins (rATG) may not only result from immunodepletion but also from the induction of T cells that control allogeneic immune responses. In the present prospective and controlled study, we investigated the effect of rATG on the frequency, function and phenotype of peripheral immunoregulatory CD4+ T cells in kidney transplant (KTx) patients.Methods. After transplantation, 16 patients received ATG-induction therapy and triple therapy consisting of tacrolimus, MMF and steroids. The control group (n = 18) received triple therapy only. By flow cytometry, T cells were analysed for CD25, FoxP3, CD127, CD45RO and CCR7. To study their suppressive capacities, CD25bright T cells were co-cultured with CD25-dim effector T cells (Teff) in mixed lymphocyte reactions (MLR), stimulated with donor and third party (3P) antigens.Results. Pre-transplant levels of FoxP3+CD127-low T cells were 6 of CD4+ T cells. One week post-ATG treatment, no measurable numbers of regulatory T cells were present (P < 0.01). After 4 weeks, the cell numbers of CD4+FoxP3+CD127-low T cells slowly reappeared and thereafter remained low (P < 0.01). At 14 weeks, a significant shift towards the CD45RO+CCR7+ (central memory) phenotype within CD4+FoxP3+ T cells was observed (P < 0.01). At 26 weeks, the proliferative alloresponses of the PBMC and CD25-dim Teff profoundly decreased compared to pre-transplant (P = 0.01 and P = 0.02 respectively), while the regulatory capacity of the CD25bright T cells, of which 90 consisted of FoxP3+CD127-low T cells, remained unaffected. The CD25bright T cells suppressed the anti-donor (94) and 3P responses (93).Conclusion. Our findings show that rATG therapy does not spare peripheral immunoregulatory T cells in vivo, but after regeneration preserves their suppressive activity.

Inadequate immune regulatory function of CD4+CD25bright+FoxP3+ T cells in heart transplant patients who experience acute cellular rejection (Article)

2009-04-27T00:00:00Z

BACKGROUND.: CD4CD25FoxP3 regulatory T cells are suppressors of antigen-activated immune reactivity. Here, we assessed the clinically relevant role of these cells in the control of immune responses directed to a transplanted heart. METHODS.: We investigated the phenotype and function of peripheral CD4CD25FoxP3 T cells in heart transplant patients free from acute rejections (n=9) and in rejectors (n=12) before and during acute cellular rejection. RESULTS.: Between rejectors and nonrejectors, the proportion of CD4CD25 T cells and of FoxP3 cells within this population was comparable. Yet, CD4CD25FoxP3 T cells of rejectors had a higher CD127 expression than those of nonrejectors (P=0.0001). Depletion of CD4CD25 T cells from peripheral blood mononuclear cells increased the antidonor proliferative response of both nonrejectors (P≤0.0005) and rejectors (P≤0.03). In rejectors, however, only a 2-fold increase was measured, whereas the nonrejectors' response became 14 times higher (P=0.002). Reconstitution of CD4CD25 T cells only suppressed the overall antidonor proliferative response of CD25 responder cells of nonrejectors significantly (P=0.001). Moreover, the percentage inhibition of the response was higher in nonrejectors than in rejectors (P=0.02). Analyses of pretransplant samples revealed that CD4CD25 T cells of rejectors already had a lower suppressive capacity than those of nonrejectors before transplantation (P=0.04). CONCLUSION.: CD4CD25FoxP3 T cells of heart transplant patients who experience acute rejection had an up-regulated CD127 expression and an inadequate regulatory function compared with those of nonrejecting patients. Our observations suggest that the function of circulating CD4CD25FoxP3 regulatory T cells may be pivotal for the prevention of acute cellular rejection after clinical heart transplantation.

Long-term survival after kidney transplantation in an HIV-positive patient (Article)

2009-04-17T00:00:00Z

Only a decade ago, human immunodeficiency virus (HIV)-seropositivity was considered an absolute contraindication for organ transplantation. With the currently available experience, it is no longer justified to deny HIV-positive patients access to transplantation. To the best of our knowledge, we here present the longest surviving HIV-positive patient after renal transplantation. The follow-up period after renal transplantation in this HIV-positive female is now 13 yr and she is in good general condition with excellent renal function. Throughout her post-transplant follow-up, we encountered a number of problems that are illustrative of the HIV-positive patient.

Potential of mesenchymal stem cells as immune therapy in solid-organ transplantation (Article)

2009-04-01T00:00:00Z

Over the last decade, there has been a rising interest in the use of mesenchymal stem cells (MSCs) for clinical applications. This interest stems from the beneficial properties of MSCs, which include multi-lineage differentiation and immunosuppressive ability, suggesting there is a role for MSC therapy for tissue regeneration and in immunologic disease. Despite recent clinical trials investigating the use of MSCs in treating immune-mediated disease, their applicability in solid-organ transplantation is still unknown. In this review, we identified topics that are important when considering MSC therapy in clinical organ transplantation. Whereas, from other clinical studies, it would appear that administration of MSCs is safe, issues like dosing, timing, route of administration, and in particular the use of autologous or donor-derived MSCs may be of crucial importance for the functional outcome of MSCs treatment in organ transplantation. We discuss these topics and assess the feasibility of MSCs therapy in organ transplantation.

T-cell reactivity during tapering of immunosuppression to low-dose monotherapy prednisolone in HLA-identical living-related renal transplant recipients (Article)

2009-03-27T00:00:00Z

BACKGROUND.: In many transplant centers, human leukocyte antigen (HLA)-identical living-related (LR) renal transplant recipients receive standard maintenance immunosuppression from 1 year after transplantation. We questioned whether discontinuation of azathioprine (AZA) or mycophenolate mofetil (MMF) influenced T-cell reactivity, circulating dendritic cell (DC) subsets numbers and their maturation status. METHODS.: Twenty-nine HLA-identical LR renal transplant recipients were withdrawn from AZA or MMF. Thereafter, the patients received only prednisolone. T-cell reactivity was determined by interferon-γ (n=23), interleukin (IL)-10 (n=16), and granzyme B (n=10) Elispot assays. Circulating DC subset numbers and their maturation status determined by CCR2, CCR5, CCR7, and CD83 expression were measured by flow cytometry (n=12). RESULTS.: The number of donor, third-party, and tetanus toxoid-reactive interferon-γ and granzyme-B producing cells was not affected after withdrawal of immunosuppression. Discontinuation of AZA or MMF resulted in significant increased numbers of third-party (P=0.003) and tetanus toxoid-reactive (P=0.008) IL-10 producing cells, and a trend in higher numbers of donor-reactive IL-10 producing cells (P=0.06). No effect was found on the number of circulating DC subsets, but DC was shifted toward a more mature phenotype. CONCLUSIONS.: In HLA-identical LR renal transplant recipients, therapy with AZA and MMF suppress the IL-10 production and the maturation of DC. This suggests that these immunosuppressants may hinder suppression of immune responses in general, including allogeneic responses.

Donor-derived mesenchymal stem cells suppress alloreactivity of kidney transplant patients (Article)

2009-03-27T00:00:00Z

BACKGROUND.: Human mesenchymal stem cells (MSC) have immunosuppressive capacities. Although their efficacy is currently studied in graft-versus-host disease, their effect on alloreactivity in solid organ transplant patients is unknown. In this study, the immunosuppressive effect of MSC on recipient anti-donor reactivity was examined before and after clinical kidney transplantation. METHODS.: Anti-donor reactivity was established in pretransplant and posttransplant mixed lymphocyte reactions (MLR) of 14 living-kidney donor-recipient pairs. MSC from donors and third-party controls were added to the MLR in a ratio of 1:5. RESULTS.: MSC were isolated from donor perirenal fat and showed multilineage differentiation potential and the capacity to inhibit lymphocyte proliferation. The immunosuppressive effect of MSC was dose dependent and mediated by cell-membrane contact and soluble factors, including interleukin-10 and indoleamine 2,3-dioxygenase.Donor-derived MSC significantly inhibited the recipient anti-donor reactivity before and 1 month after transplantation. This effect was independent of human leukocyte antigen background of MSC. Flow cytometric analysis showed that MSC inhibited the proliferation of CD4 and CD8 T-lymphocyte subsets in pretransplant and posttransplant donor-directed MLR, whereas MSC had no effect on B- or natural killer-cell proliferation. CONCLUSION.: Donor MSC significantly inhibited the proliferation of alloactivated recipient T cells before and after kidney transplantation. We believe these findings should encourage MSC-based intervention in clinical organ transplantation.

Successful tapering of immunosuppression to low-dose monotherapy steroids after living-related human leukocyte antigen-identical renal transplantation (Article)

2009-03-15T00:00:00Z

Background. Living-related (LR) human leukocyte antigen (HLA)-identical renal transplant (RTx) recipients often receive standard immunosuppression, despite the absence of mismatched major HLA-antigens and the known complications of long-term use of immunosuppression. No data are available on the need for immunosuppression for these specific patients. We wondered whether their immunosuppressive load could be radically reduced. Method. Between November 1982 and November 2005, 83 LR HLA-identical RTx were performed in our center. Their unadjusted graft survival was 74% at 10 years. In 29 patients (median time after transplantation 5.6 [range 1.0-21.4] years) with stable uncompromised renal function, we tapered their immunosuppression from triple or dual therapy to prednisolone 5 mg/day. Follow up on prednisolone monotherapy was at least 24 months. Results. In 27 of 29 patients reduction of immunosuppression to prednisolone monotherapy was uneventful. One patient, using dual therapy, developed JC-virus nephropathy resulting in graft loss. One refused further discontinuation of his medication. Four (15%) of the 27 patients on monotherapy developed biopsy-proven recurrence of their original disease. Only one of them showed a transient decline in renal function. One additional patient developed minor proteinuria and a rise in serum creatinine level, as a result of chronic urinary tract infections. The remaining 23 of 27 patients (85%) had an uneventful follow up during 24 months prednisolone monotherapy. Conclusion. We conclude that HLA-identical LR RTx recipients who are at least 1 year after transplantation might be treated with low-dose steroid monotherapy. Close surveillance of patients for recurrence of their original disease is recommended to allow for potential early therapeutic intervention.

Laparoscopic donor nephrectomy: A plea for the right-sided approach (Article)

2009-03-15T00:00:00Z

Background. Laparoscopic donor nephrectomy (LDN) has become the preferred procedure for live donor nephrectomy. Most transplant surgeons are reluctant toward right-sided LDN (R-LDN) fearing short vessels and renal vein thrombosis. Methods. In our institution, selection of the appropriate kidney for donation was based on the same criteria that traditionally governed open donor nephrectomy. All intraoperative and postoperative data were prospectively recorded. Results. One hundred fifty-nine R-LDNs (56%) and 124 left-sided LDNs (1-LDN, 44%) were performed. Demographics did not significantly differ. Complications occurred in 10 (6%) vs. 23 (19%) procedures (R-LDN vs. L-LDN, P=0.002), resulting in 2 and 11 conversions, respectively. Right-sided kidney donation was the only independent preventative factor for complications in multivariate analysis (P=0.008, Odds ratio 0.33). R-LDN was associated with shorter operation time (mean 202 vs. 247 min, P<0.001) and less blood loss (139 vs. 294 mL, P<0.001). Hospital stay was 3 days in both groups. With regard to the recipients, the second warm ischemia time was similar (29 vs. 28 min, P=0.699). Conclusions. R-LDN is faster and safer than L-LDN and does not adversely affect graft function. R-LDN may be advocated to allow donors to benefit from the advantages of laparoscopic surgery. Copyright

Generation of donor-specific regulatory t-cell function in kidney transplant patients (Article)

2009-02-15T00:00:00Z

Background.: In the search for mechanisms that can induce and maintain transplant tolerance, donor-specific CD4CD25FoxP3 regulatory T cells have been frequently mentioned. However, it remains to be demonstrated, whether these cells are generated after clinical transplantation. Methods.: We prospectively analyzed the phenotype and function of peripheral regulatory CD4CD25 T cells of 79 patients before, 3, 6, and 12 months after kidney transplantation. The immune regulatory capacities of CD4CD25 T cells were assessed by their depletion from peripheral blood mononuclear cells and in co-culture with CD25 responder T-cells in the mixed lymphocyte reactions. Results.: In the first year after transplantation, the number and proportion of CD4CD25 T cells significantly decreased (P<0.05 and P<0.001, respectively). In the mixed lymphocyte reactions, we observed donor-specific hyporesponsiveness in the presence of significantly increased proliferation to third and fourth Party-Ag, (P<0.001 and P<0.05, respectively). Furthermore, functional analysis of CD25 cells showed that the effect of depletion of these cells from peripheral blood mononuclear cells, and their suppressive capacities in co-culture with donor-Ag stimulated CD25 responder T-cells (1:10 ratio) significantly improved (P<0.01 and P<0.001, respectively). Moreover, the difference between the stimulation with donor-Ag and third Party-Ag became apparent at 6 months after transplantation. Conclusions.: These findings demonstrate that donor-specific CD4CD25 regulatory T-cell function is generated in fully immunosuppressed renal recipients in the first year after transplantation.

Early living-donor kidney transplantation: A review of the associated survival benefit (Article)

2009-02-15T00:00:00Z

Avoidance of dialysis-related morbidity, improvement in quality of life, and reduction of costs have been mentioned as advantages of preemptive kidney transplantation. However, this therapeutic option is underutilized. Previous studies assessing the patient survival benefit of preemptive kidney transplantation compared it with postdialysis kidney transplantation. These studies may have been subjected to lead-time bias. When comparing patient survival of preemptive kidney transplant patients with waitlisted dialysis patients, there is a clear patient survival advantage in favor of preemptive kidney transplantation. This benefit justifies encouragement of preemptive kidney transplantation.

Donor-specific immune regulation by CD8+ lymphocytes expanded from rejecting human cardiac allografts (Article)

2009-02-01T00:00:00Z

To assess whether regulatory T cells are present in rejecting human cardiac allografts, we performed functional analyses of graft lymphocytes (GLs) expanded from endomyocardial biopsies (EMB; n = 5) with histological signs of acute cellular rejection. The GL cultures were tested for their proliferative capacity and regulatory activity on allogeneic-stimulated peripheral blood mononuclear cells (PBMC) of the patient (ratio PBMC:GLs = 5:1). Three of these GL cultures were hyporesponsive to donor antigens and suppressed the antidonor proliferative T-cell response of PBMC, but not the anti-third-party response. Interestingly, it was the CD8+GL subset of these cultures that inhibited the antidonor response (65-91% inhibition of the proportion of proliferating cells); the CD4+GLs of the expanded GL cultures were not suppressive. In conclusion, CD8+GLs expanded from rejecting human cardiac allografts can exhibit donor-specific immune regulatory activities in vitro. We suggest that during acute cellular rejection, GLs may not only consist of graft-destructing effector T cells, but also of cells of the CD8+type with the potential to specifically inhibit antidonor immune reactivity.

The effect of the JAK inhibitor CP-690,550 on peripheral immune parameters in stable kidney allograft patients (Article)

2009-01-15T00:00:00Z

Introduction.: CP-690,550 inhibits Janus kinase 3 (JAK3) which mediates signal transduction of receptors of the common γ-chain cytokines. These cytokines play key roles in lymphocyte function and homeostasis. As part of a phase 1 trial, we evaluated the effect of CP-690,550 on immune parameters. Material.: Stable kidney transplant recipients (n=8) receiving mycophenolate mofetil and prednisolone were treated with CP-690,550, 30 mg twice daily orally for 29 days. Blood samples were collected on days 1 (before first dose), 15, 29 (end of treatment), and 57. Results.: Two patients experienced minor infections (one urinary tract infection and one mild respiratory tract infection). Leukocyte counts remained stable, whereas a mean decrease in hemoglobulin of 8% was measured (P=0.01). CP-690,550 treatment for 29 days resulted in statistically significant changes in the number of circulating CD19 B cells (P=0.05), CD3CD16CD56 natural killer-cells (P<0.01), and CD4CD25 T cells (P=0.05; one-way analysis of variance). After CP-690,550 treatment on day 15 the number of B cells increased by a mean of 100%, (P=0.04), whereas those of natural killer cells and CD4CD25 T cells decreased by 65% (P=0.001) and 38% (P=0.03, t test), respectively, from pretreatment baseline. However, the regulatory capacities of the residual CD4CD25 T cells remained unchanged pre- and posttreatment. In addition, in the presence of CP-690,550, the interferon-γ production capacity of peripheral blood mononuclear cells was reduced by 39% (median) compared with predose baseline (P=0.01). Conclusions.: These findings demonstrate the role of JAK3 in the homeostasis and function of select lymphocyte subpopulations. JAK3 inhibition may provide a novel mechanism for the modulation of allogeneic responses in patients after transplantation.

Blood dendritic cell levels and phenotypic characteristics in relation to etiology of end-stage heart failure: Implications for dilated cardiomyopathy (Article)

2009-01-09T00:00:00Z

Background: Dysregulation of dendritic cell (DC) mediated immune responses towards auto-antigens, is considered an important feature in the maintenance of experimentally induced heart failure (HF). In order to evaluate the role of blood DCs in cardiomyopathies of different origins, we examined myeloid (mDC) and plasmacytoid (pDC) subset levels and maturation characteristics, according to HF severity and etiology in humans. Methods: Absolute numbers of mDCs and pDCs in 12 New York Heart Association (NYHA) class-II, 28 NYHA class III-IV HF patients and 18 healthy controls, were studied by 4-colour whole blood flow cytometry. Results: End-stage (NYHA III-IV) HF patients had comparable circulating DC subset levels to NYHA-II patients and controls. However, within the NYHA III-IV group total DC levels in patients with non-ischemic dilated cardiomyopathy (DCM) were higher (P < 0.001) than in patients with coronary artery disease (CAD), hypertrophic cardiomyopathy (HCM) or other HF etiology. This was due to a significant increase of primarily mDCs (P < 0.0001) and to a lesser extent of pDCs (P < 0.05) in idiopathic DCM patients, independent of systolic or diastolic cardiac dysfunction. Maturation marker CD83 and lymphoid homing chemokine receptor CCR7 surface expression was enhanced only on mDCs, but not pDCs from DCM patients (P < 0.05), compared to patients with CAD, HCM or other underlying cardiac pathophysiology. Conclusions: Total blood DC levels in end-stage HF are elevated in patients with DCM. Whole blood DC characterisation may lead to new insights into the pathophysiology of idiopathic DCM in humans.

Strategies to advance living kidney donation: a single center's experience. (Article)

2009-01-01T00:00:00Z

In Europe, living kidney donation rates differ considerably from country to country. These differences are related to deceased kidney donation rates: countries with higher deceased donation rates have lower living donation rates. Despite the differences, all countries have one thing in common, namely, the shortage of kidneys for transplantation. Living kidney donation is a good option to alleviate these shortages. In our center, 60% to 70% of all kidney transplants come from living donors. This article describes various strategies that may have contributed to these high living donation rates: team attitude, educational materials and meetings, and alternative donation programs (exchange donation, domino-paired donation, Good Samaritan donation). Also described are some less conventional strategies for increasing rate of living kidney donation that are not used in the Netherlands but may offer some good perspectives (e.g., the "Norwegian approach" and home-based educational programs).

Avoiding the issue: Patients' (non)communication with potential living kidney donors (Article)

2009-01-01T00:00:00Z

Objective: Kidney transplantation with a living donor has proved to be an effective solution for kidney patients on the waiting list for transplantation. Nevertheless, it may be difficult to find a living kidney donor. The purpose of this explorative study is to investigate how kidney transplant candidates may, or may not, find a living donor in the Netherlands. Methods: We compared a group of 42 patients who did not find a living donor with a group of 42 patients who did, using semi-structured interviews. Results: We found that, although almost all patients recognized the advantages of living kidney donation and were willing to accept the offer of a living kidney donor, many found it very difficult to ask a potential donor directly. This was true for both groups. Conclusion: Patients may gain from professional support to deal with this situation in ways that balance their medical needs and their personal relationships. Practice Implications: Support programs should be developed to assist patients in developing strategies for discussing living kidney donation with potential donors.

Donor-derived mesenchymal stem cells remain present and functional in the transplanted human heart (Article)

2009-01-01T00:00:00Z

Mesenchymal stem cells (MSC) are characterized by their multilineage differentiation capacity and immunosuppressive properties. They are resident in virtually all tissues and we have recently characterized MSC from the human heart. Clinical heart transplantation offers a model to study the fate of transplanted human MSC. In this study, we isolated and expanded MSC from heart tissue taken before, and 1 week up to 6 years after heart transplantation. MSC from posttransplantation tissue were all of donor origin, demonstrating the longevity of endogenous MSC and suggesting an absence of immigration of recipient MSC into the heart. MSC isolated from transplanted tissue showed an immunophenotype that was characteristic for MSC and maintained cardiomyogenic and osteogenic differentiation capacity. They furthermore preserved their ability to inhibit the proliferative response of donor-stimulated recipient peripheral blood mononuclear cells. In conclusion, functional MSC of donor origin remain present in the heart for several years after transplantation.

Hurdles, barriers, and successes of a national living donor kidney exchange program (Article)

2008-12-27T00:00:00Z

BACKGROUND.: Living donor kidney exchange is now performed in several countries. However, no information is available on the practical problems inherent to these programs. Here, we describe our experiences with 276 couples enrolled in the Dutch program. METHODS.: Our protocol consists of five steps: registration, computerized matching, crossmatching, donor acceptation, and transplantation. We prospectively collected data of each step of the procedure. RESULTS.: Of the 276 registered pairs we created 183 computer-matched combinations. However, 62 of 183 recipients proved to have a positive crossmatch with their new donor, which was not predicted by the screening results of the recipient centers. Alternative solutions were found for 39 couples, resulting in a total of 160 new combinations with negative crossmatches. Thereafter, because of 22 individual clinical problems, the exchange procedure had to be discontinued for 51 couples while only for 19 of them alternative solutions were found. At the end of day, 128 patients had received exchange kidneys, 55 were transplanted outside the program, 59 are still on the crossover waitlist, and 34 had left the program for medical or psychological reasons. CONCLUSION.: A living donor kidney exchange program is a dynamic process. Many clinical hurdles and barriers are encountered that for a large part were not foreseen but should be taken into account when programs are initiated based on computer simulations. Success is dependent on a flexible organization able to create alternative solutions when problems arise. Centralized allocation and crossmatch procedures are instrumental in this respect.

Susceptibility of human mesenchymal stem cells to tacrolimus, mycophenolic acid, and rapamycin (Article)

2008-11-15T00:00:00Z

BACKGROUND.: Mesenchymal stem cells (MSC) have multilineage differentiation and immunomodulatory capacities and are potentially useful for therapeutic applications, such as tissue regeneration and control of alloreactivity. MSC are present in most tissues including the transplantable organs. It is therefore unavoidable that MSC will be exposed to immunosuppressive drugs in a clinical transplantation setting. The molecular targets of these drugs are expressed in MSC, but the effect of their inhibition on MSC functioning is unknown. METHODS.: MSC were isolated and expanded from heart tissue and the effects of the calcineurin inhibitor tacrolimus, the cell cycle inhibitor mycophenolic acid (MPA), and the mammalian target of rapamycin inhibitor on MSC survival, proliferation, differentiation, and immunosuppressive capacity were examined. RESULTS.: Short-term exposure to the immunosuppressants did not induce toxicity or apoptosis in MSC, but high-dose tacrolimus induced toxicity after 7 days. MPA and rapamycin inhibited MSC proliferation at therapeutic doses. The immunosuppressants had differential effects on the differentiation capacity of MSC. Tacrolimus reduced the expression of troponin T type 2 and desmin during cardiomyogenic differentiation of MSC, whereas MPA decreased the deposition of calcified minerals during osteogenic differentiation. Rapamycin stimulated lipid production during adipogenic differentiation. Unexpectedly, MSC had adverse effects on the immunosuppressive efficacy of tacrolimus and rapamycin. There was no such effect of MSC on the function of MPA. Preincubation of MSC with tacrolimus increased the immunosuppressive capacity of MSC. DISCUSSION.: This study demonstrates that therapeutic concentrations of immunosuppressive drugs affect MSC function. MSC affect the efficacy of immunosuppressive medication. These findings are important for potential clinical use of MSC in combination with immunosuppressants.

Quiz page. Muckle Wells syndrome. (Article)

2008-11-01T00:00:00Z

Functional analysis of CD4+ CD25 bright T cells in kidney transplant patients: Improving suppression of donor-directed responses after transplantation (Article)

2008-10-01T00:00:00Z

Background: The role of CD4+ CD25bright regulatory T cells (Treg) in controlling alloreactivity is established, but little is known whether antigen-specific Treg are induced in fully immunosuppressed kidney transplant patients. Methods: The frequency and function of CD25bright T cells of nine stable kidney transplant patients before and 0.5-2yr after transplantation were measured. Patients received triple therapy consisting of cyclosporine, mycophenolate mofetil and prednisone. To investigate the influence of transplantation and immunosuppression on Treg function, we compared their suppressive capacities pre- and post-transplantation using mixed lymphocyte reactions and kept the CD25-/dim effector T-cell (Teff) population constant. Results: After transplantation, the percentage of CD4+ CD25bright T cells significantly decreased from 8.5% pre-transplant to 6.9% post-transplant (median, p=0.05). However, the lower percentage of post-transplant CD4+ CD25bright T cells was not associated with reduced, but rather improved suppressor function of these cells. The proliferative response of pre-transplant Teff to donor-antigens was more profoundly suppressed by post-transplant Treg than by pre-transplant Treg (pre-transplant 18% vs. post-transplant 55% median, p=0.03) and was comparable against third party antigens at a CD25bright:CD25-/dim ratio of 1:20. Conclusions: In immunosuppressed kidney transplant patients, the donor-directed suppressive capacity of CD4+ CD25bright regulatory T cells improved, which may contribute to the development of donor-specific hyporesponsiveness against the graft.

Associations between pre-kidney-transplant risk factors and post-transplant cardiovascular events and death (Article)

2008-10-01T00:00:00Z

The prevalence of cardiovascular risk factors in renal transplant candidates is high. A better understanding of the relation between these risk factors and cardiovascular morbidity and mortality is mandatory to improve transplantation outcome. In this retrospective cohort study 2187 adult patients who received a first kidney transplant between 1984 and 1997 were included. We analyzed the incidence of post-transplant cardiovascular events and tried to identify independent pretransplant risk factors for post-transplant cardiovascular events and all-cause mortality. The cumulative incidence of post-transplant cardiovascular events was 40%. The incidence was highest in the first 3 months after transplantation. Independent pretransplant risk factors for a post-transplant cardiovascular event were diabetic nephropathy [Hazard ratio (HR) 3.02; 95% CI 2.85-3.98], claudication [HR 2.17 (1.42-3.31)], cardiac event [HR 1.76 (1.32-2.33)], cerebrovascular accident HR 1.53 (1.03-2.28), time-on-dialysis [HR 1.06 (1.02-1.11)], recipient age [HR 1.04 (1.04-1.05)], and body mass index [HR 1.03 (1.00-1.05)]. Diabetic nephropathy and cardiovascular disease were also important predictors for all-cause mortality. Diabetic nephropathy and cardiovascular disease were the most important predictors for cardiovascular events and all-cause mortality after renal transplantation. Early treatment of cardiovascular risk factors and pretransplant cardiovascular evaluation might improve transplantation outcome.

Expansion of cytolytic CD4+CD28- T cells in end-stage renal disease (Article)

2008-09-01T00:00:00Z

Cytomegalovirus (CMV) seropositivity is associated with increased risk for atherosclerotic disease in patients with end-stage renal disease. This association is due to a unique peripheral blood CD4+T cell population which lack CD28 (CD4+CD28-T cells). Here we found that this patient population has a significant age-dependent increase of CD4+CD28-T cells that comprise over half of the circulating CD4 T cells in some. Patients over 50 years of age have a 50-fold higher percentage of CD4+CD28-T cells compared to seronegative patients and a 5-fold higher percentage when compared to seropositive healthy controls. Stimulation by CMV-antigen or by polyclonal stimulation using PMA and ionomycin showed that CD4+CD28-cells in patients with end stage renal disease degranulated and secreted interferon γ thus indicating that they are cytolytic. The average anti-CMV IgG titer displayed a remarkable age-dependent increase only in patients with end stage renal disease. These findings are highly suggestive of repetitive antigenic stimulation of the immune system in patients with end stage disease by subclinical CMV reactivation which might contribute to increased atherosclerotic risk.

Ingredients for a successful living donor kidney exchange program (Article)

2008-08-27T00:00:00Z

Phase 1 dose-escalation study of CP-690 550 in stable renal allograft recipients: Preliminary findings of safety, tolerability, effects on lymphocyte subsets and pharmacokinetics (Article)

2008-08-01T00:00:00Z

CP-690 550 inhibits Janus kinase 3 with nanomolar potency. In this dose-escalation study, we assessed the safety, tolerability, effects on lymphocyte subsets, and pharmacokinetics of CP-690 550 when coadministered with mycophenolate mofetil in stable renal allograft recipients for 28 days. Twenty-eight patients were enrolled. Six patients received CP-690 550 5 mg twice daily (BID), 6 patients received 15 mg BID, 10 patients received 30 mg BID, and 6 patients received placebo. The most frequent adverse events were infections and gastrointestinal (abdominal pain, diarrhea, dyspepsia, and vomiting). CP-690 550 15 mg BID and 30 mg BID were associated with a mean decrease in hemoglobin from baseline of 11% and a mean decrease in absolute natural killer cell counts of 50%. CP-690 550 30 mg BID was also associated with a mean increase in absolute CD19+B-lymphocytes of 130%. There were no changes in the number of neutrophils, total lymphocytes, platelets, or CD4+or CD8+T cells; clinical chemistry; vital signs; or electrocardiograms from the pretreatment baseline. Administration of CP-690 550 without a concomitant calcineurin inhibitor resulted in CP-690 550 exposures consistent with previous studies in nontransplant subjects. Additional dose-ranging studies are warranted to evaluate the safety and efficacy of CP-690 550 in renal transplant recipients over longer treatment duration.

Regulatory T cells after organ transplantation: Where does their action take place? (Article)

2008-07-01T00:00:00Z

Regulatory T cells are considered to be pivotal for the induction of tolerance to donor antigens. In the past decades, several regulatory T-cell subsets have been identified, such as CD4+CD25+ regulatory T cells and the CD8+CD28- suppressor T cells. Although many studies have investigated the role of these regulators in transplant tolerance, relatively little attention has focused on the exact place where these cells suppress immune responses directed to donor antigens. The localization of regulatory T cells may influence their effect on allogeneic immune responses. More insight into the localization and migration of regulatory T cells in transplant recipients is therefore important, especially when these cells are to be used for monitoring purposes and for cellular immune therapy. In the present review we summarize current knowledge about the presence of functional donor-directed regulatory T cells in the secondary lymphoid organs, peripheral blood, and the transplanted organ itself. In addition, we discuss the importance of the appropriate localization for the control of anti-donor immune reactivity.

Tapering immunosuppressive therapy significantly improves in vivo cutaneous delayed type hypersensitivity responses (Article)

2008-07-01T00:00:00Z

Immunosuppressive therapy affects cell-mediated immunity and thereby increases the frequency of infections and malignancies in transplanted patients. We questioned whether reducing the immunosuppressive dose in stable kidney transplant patients has an in vivo effect on cutaneous delayed type hypersensitivity responses (DTH) reflecting cell-mediated immunity. We measured DTH responses to recall antigens (Tetanus, Diphteria, Streptococcus, Tuberculin, Candida, Trychophyton, Proteus, glycerin control) on the volar surface of the forearm in patients before and after successful reduction (50%) of the dose of mycophenolate mofetil (MMF) or azathioprine (AZA). In addition, we tested healthy individuals who were age- and sex-matched to the patient group. Results of the skin reaction test were calculated as the sum in millimeters (mm) of all positive reactions (score), and as the number of positive antigens. Patients treated with a high dose of MMF or AZA had a significantly lower test score compared to healthy controls (p = 0.01). Also the number of positive antigens was reduced in patients compared to healthy controls (p = 0.02). After reduction of the MMF or AZA dose, the test score and the number of positive antigens increased significantly (p = 0.02, p = 0.01, respectively) to comparable scores of healthy controls. Additionally, the mycophenolic acid (MPA) trough level was negatively correlated with the test score (p = 0.006) and number of positive antigens (p = 0.004). In conclusion, successful tapering of the MMF or AZA dose in kidney transplant patients more than 2 years after transplantation favorably affects the in vivo DTH response, reflecting an improvement of the general immunity, facilitating the defense against infection and malignancies.

Complex vascular anatomy in live kidney donation: Imaging and consequences for clinical outcome (Article)

2008-06-27T00:00:00Z

BACKGROUND.: Live donor kidneys with multiple arteries are associated with surgical complexity for removal and increased rate of recipient ureteral complications. We evaluated the outcome of vascular imaging and the clinical consequences of multiple arteries and veins. METHODS.: From 2001 to 2005 data of 288 live kidney donations and transplantations were prospectively collected. Vascular anatomy at operation was compared with vascular anatomy as imaged by magnetic resonance imaging (MRI) or subtraction angiography, and consequences of multiple vessels were investigated. RESULTS.: Simple renal anatomy with a solitary artery and vein was present in 208 (72%) kidneys. Sixty (21%) transplants had multiple arteries. Thirty (10%) transplants had multiple veins. Magnetic resonance imaging failed to predict arterial anatomy in 23 of 220 donors (10%) compared with 3 of 101 (3%) after angiography. The presence of multiple veins did not influence outcomes after nephrectomy in general. Multiple arteries did not affect clinical outcomes in open donor nephrectomy (n=103). In laparoscopic donor nephrectomy (n=185) multiple arteries were associated with longer operation times (245 vs. 221 min, P=0.023) and increased blood loss (225 vs. 220 mL, P=0.029). In general, neither multiple arteries nor vascular reconstructions influenced recipient creatinine clearance or ureteral complication rate. However, accessory arteries to the lower pole correlated with an increased rate of ureteral complications (47% vs. 14%, P=0.01). CONCLUSIONS.: Multiple arteries may increase operation time. Accessory lower pole arteries are associated with a higher rate of recipient ureteral complications indicating the importance of arterial imaging. Currently, both magnetic resonance imaging and angiography provide suboptimal information on renal vascular anatomy.

The Control of Anti-Donor Immune Responses by Regulatory T Cells in Organ Transplant Patients (Article)

2008-06-01T00:00:00Z

The role of regulatory T cells in the induction and maintenance of transplant tolerance has been widely investigated in experimental animal models. Their involvement in the regulation of allogeneic immune reactivity in immunosuppressed organ transplant patients, however, remains unclear. Measurements of regulatory T cells after clinical organ transplantation may contribute to understanding their role in anti-donor immune responses. Several studies have investigated the frequency and/or immune regulatory function of peripheral regulatory T-cell populations, such as, the CD4+CD25+regulatory T cells or the CD8+CD28-suppressor T cells, in clinically stable organ transplant patients and patients with acute or chronic rejection. This review summarizes these studies and discusses the correlations found between the number and function of regulatory T cells and the immunological state of the patient. This knowledge is warranted for a better understanding of the control of allogeneic immune responses by regulatory T cells. Subsequently, monitoring regulatory T cells may help us to identify patients in whom the anti-donor reactivity is actively suppressed.

Donor-reactive cytokine profiles after HLA-identical living-related kidney transplantation (Article)

2008-06-01T00:00:00Z

Background. After HLA-identical living-related (LR) kidney transplantation, only non-HLA antigen mismatches between donor and recipient may exist. We questioned whether donor-reactive responses against non-HLA antigens could be found after HLA-identical LR kidney transplantation, and wondered whether donor reactivity in the HLA-identical setting was different from the HLA-mismatched setting during immunological quiescence. Healthy individuals served as controls. Methods. Elispot assays were performed to determine the number of alloreactive IFN-γ-producing cells (pc), IL-10 pc, granzyme B (GrB) pc and IL-13 pc from peripheral blood mononuclear cells (PBMC) of HLA-identical, HLA-mismatched LR kidney transplant recipients and healthy individuals. Results. The frequency of alloreactive IFN-γ pc, IL-13 pc and GrB pc was higher in healthy individuals compared to both transplant patient groups. In the HLA-identical group, significantly higher numbers of donor-reactive IL-10 pc were found compared to their autologous control. These frequencies were also higher compared to the HLA-mismatched and healthy control group. The number of donor-reactive GrB pc was higher in the HLA-mismatched group than in the HLA-identical group. Donor-reactive IFN-γ pc and IL-13 pc were comparable in both transplant groups. Conclusions. In recipients of HLA-identical LR kidney transplant, high donor-reactive IL-10 pc, in combination with low donor-reactive IFN-γ pc, IL-13 pc and GrB pc, suggests active downregulation of reactivity against non-HLA molecules.

After discontinuation of calcineurin inhibitors, tapering of mycophenolate mofetil further impairs donor-directed cytotoxicity (Article)

2008-03-01T00:00:00Z

Background: Recently, we described a significant decrease in donor-specific cytotoxic T-lymphocyte precursor frequency (CTLpf) after discontinuation of calcineurin inhibitors (CNI), while the proliferative capacity in mixed lymphocyte culture (MLC), and the number of interferon-γ (IFN-γ) producing cells (pc) in Elispot remained unchanged. Methods: We tested T-cell reactivity in CNI free patients with stable renal graft function, on mycophenolate mofetil (MMF) or azathioprine (AZA) plus prednisone, who were tapered to 50% of their MMF or AZA dose. Results: Furthermore, tapering of the MMF or AZA dose resulted in a decrease of donor-reactive CTLpf in all patients with detectable CTLpf. Detectable numbers decreased from a median of 32 to 8 CTLp/106 peripheral blood mononuclear cell (PBMC). No effect on third-party reactive CTLpf was found, while the T-cell reactivity to donor and third-party cells as tested in MLC and in IFN-γ Elispot was not affected either by tapering of immunosuppression. Third-party reactivity was significantly higher than donor-specific reactivity in all tests. A control group showed no changes in any of the in vitro assays. Conclusion: Both withdrawal of CNI and tapering of MMF or AZA dose decreases the donor-specific CTLpf. Our data suggest that reduction of immunosuppression results in a specific decrease of donor-directed cytotoxic capacity of immunocompetent cells, while their proliferation and cytokine production capacity remained unchanged. Immunosuppression hinders development of cytotoxic non-responsiveness.

Q-methodology to identify young adult renal transplant recipients at risk for nonadherence (Article)

2008-03-01T00:00:00Z

BACKGROUND. Young adult renal transplant recipients may display patterns of behavior that affect graft survival. The present study aimed to identify young adults at risk for nonadherent behavior by investigating their attitudes about posttransplant health lifestyle. METHOD. A Q-methodological study was conducted. Participants were asked to rank-order statements on issues potentially associated with (non)adherence. Factor analysis was applied to uncover patterns in the ranking of statements. The resulting factors represent attitudes and are described using a composite ranking of the statements. As a first test of discriminated validity, a different group of 34 young renal transplant patients was asked how well the factor descriptions fitted them. RESULTS. Twenty-six young renal transplant recipients (18-25 years) participated in the study. They were remarkably willing to discuss sensitive issues when confronted with statements on cards. Four distinct attitude profiles concerning posttransplant health lifestyle were found among these young adults: (a) concerned and controlled, (b) appearance orientated, (c) opinionated and independent, and (d) easy going and pliable. In a follow-up analysis, self-categorization proved to discriminate well between the four attitude profiles in 67% of the respondents. CONCLUSIONS. Using Q-methodology, four attitude profiles about posttransplant health lifestyle were uncovered. Self-categorization on these attitudes seems feasible and may be a useful screening aid to identify young adults at risk for nonadherence.

Public survey of financial incentives for kidney donation (Article)

2008-03-01T00:00:00Z

Background. One of the most fiercely debated strategies to increase the number of kidneys for transplantation is the introduction of financial incentives. As the success of such strategy largely depends on public support, we performed a public survey on this topic. Methods. We developed a questionnaire on financial incentives for living kidney donation. We investigated the public opinion on two different fixed compensations: either life-long health insurance compensation or €25 000. Furthermore, we investigated public preferences on the practical implementation: either the patient seeks a donor or the donor registers for donation at an independent institute. For all examples, health insurance companies would cover costs of treatment. TNS NIPO, a professional organization for market research, sent the survey to a response panel that is made representative for the general population. Results. Five hundred fifty respondents (M/F: 60/40; median age: 46) filled out the questionnaire. Forty-six percent considered the situation wherein health insurance companies would introduce financial incentives to increase the number of living kidney donors undesirable (26% undesirable; 20% very undesirable), compared to 25% who perceived this as desirable (20% desirable; 5% very desirable). The option wherein the donor registers at an independent institute to donate to a patient on the list and in turn receives life-long health insurance compensation was chosen as most favourable. Of all respondents, 5.5% stated that there was a (very) great chance that they would donate a kidney in order to get compensation if such system were to be reality. Conclusion. Although almost half of the respondents (46%) were reluctant towards introducing a system with fixed compensation to increase the number of living kidney donors, still 25% of the general public reacted positively.

The psychological evaluation of Samaritan kidney donors: A systematic review (Article)

2008-02-01T00:00:00Z

Background. Living kidney donation to a loved one has become common practice. Another type of living donation that is becoming more acceptable to the transplant community is 'Samaritan donation'. Samaritan kidney donors are willing to donate to patients they do not know. Until recently there has been great reluctance to accept the offers of Samaritan donors because it was feared that these donors might be mentally unstable. Method. The purpose of this article is to review the literature about the psychological evaluation of potential Samaritan kidney donors for donor suitability. We have performed a systematic literature search in Pubmed, ISI Web of Science and PsycINFO. We compare and discuss how each study approaches the question about Samaritan donor selection. In addition, we have also screened the studies for reports of rejections of Samaritan donors on psychological grounds. Results. We have found five articles that at least in some detail describe the evaluation of potential Samaritan donors. For all five articles found, a consultation with either a psychiatrist or a psychologist formed a standard part of the donor evaluation procedure. This evaluation consisted of an interview, and in most instances, additional psychometric testing. According to the articles found, the two major criteria for donor rejection were psychopathology/psychological instability and motivational issues. Three studies reported on the rejection of potential donors on psychological grounds. Conclusions. The evaluation of Samaritan kidney donors is a developing field in clinical medicine. Given the relatively low incidence of these types of donations, we recommend the exchange of experience between centres that run a Samaritan donor programme, in order to improve donor evaluation criteria.

Incentives for living kidney donation: what does the public think? (Article)

2008-01-01T00:00:00Z

This mini-review describes a number of recent surveys that have been performed to study public opinion on the idea of introducing incentives for living kidney donation. The results of these surveys are comparable: about a quarter of the population is in favor of this idea, whereas the majority is opposed or undecided.

A flexible national living donor kidney exchange program taking advantage of a central histocompatibility laboratory: the Dutch model. (Article)

2008-01-01T00:00:00Z

The shortage of deceased donor kidneys for transplantation has resulted in the expansion of living donation programs. A number of possibilities have been explored, since it became clear that donors do not need to be genetically related to their recipients. Apart from classical direct donation, other options such as paired exchange, list exchange, altruistic donation and domino paired exchange programs have been implemented. In the Netherlands, patients who cannot be transplanted with their potential living donor because of ABO blood group incompatibility or a positive crossmatch, have the option to participate in a national paired kidney exchange program. The practical issues related to this program are described. The 5-years experience with the Dutch kidney exchange program is very positive as, so far, 42% of the recipients included have been transplanted. Recommendations are given for a successful implementation of a common kidney exchange program of different transplantation centers focusing on the advantage of a central histocompatibility laboratory.

FOXP3 mRNA expression analysis in the peripheral blood and allograft of heart transplant patients (Article)

2008-01-01T00:00:00Z

Previously, we demonstrated in heart transplant patients that FOXP3, a gene required for the development and function of regulatory T cells, was highly expressed in the graft during an acute cellular rejection. In this study, we analyzed whether the FOXP3 gene expression in the peripheral blood also reflects anti-donor immune responses, and therefore may provide clues for non-invasive detection of non-responsiveness or acute rejection. We examined the FOXP3 expression patterns of peripheral blood mononuclear cells (PBMC; n = 69) of 19 heart transplant patients during quiescence and rejection in comparison with those of endomyocardial biopsies (EMB; n = 75) of 24 heart transplant patients. While the FOXP3 mRNA levels were abundantly expressed in rejecting EMB (ISHLT rejection grade > 1R) compared with EMB without histological evidence of myocardial damage (ISHLT rejection grade 0R-1R; p = 0.003), no association with rejection or non-responsiveness was found for the FOXP3 mRNA levels in the peripheral blood. Thus, in contrast to intragraft FOXP3 gene expression, the peripheral FOXP3 mRNA levels lack correlation with anti-donor immune responses in the graft, and, consequently, FOXP3 does not appear to be a potential candidate gene for non-invasive diagnosis of non-responsiveness or rejection.

Beneficial effects of a new fluid regime on kidney function of donor and recipient during laparoscopic v open donor nephrectomy (Article)

2007-12-01T00:00:00Z

Background and Purpose: Laparoscopic donor nephrectomy (LDN) has been associated with delayed graft function compared with open donor nephrectomy (ODN). We have recently shown that the adverse effect of pneumoperitoneum (PP) on hemodynamics could be prevented by a new fluid regime. The aim of this study was to test the effect of this fluid regime on the kidney function of the donor and recipient after LDN and ODN. Patients and Methods: We prospectively collected data of 51 donors undergoing ODN and 59 donors undergoing LDN as well as data from the corresponding recipients. All donors and recipients were treated with a standardized anesthesia and fluid regime. This fluid regime consisted of preoperative overnight hydration together with a bolus of colloid administered before induction of anesthesia and before introduction of PP. Follow-up was 2 years. Results: Baseline characteristics of the two groups were comparable. Hemodynamics and urine output until nephrectomy were comparable between both groups. Donor kidney function did not differ after ODN and LDN. Estimated glomerular filtration rate, graft survival, and recipient survival did not differ between open and laparoscopically procured transplants. No adverse effects of the novel fluid regime (eg, pulmonary edema or additional oxygen supply) were observed in the donors. Conclusion: In contrast to our earlier findings, the kidney function of the donor and recipient is comparable between ODN and LDN after introduction of a new fluid regime.

Kinetic analysis reveals potency of CD4+ CD25bright+ regulatory T-cells in kidney transplant patients (Article)

2007-11-01T00:00:00Z

Donor-specific hyporesponsiveness as occurs after allogeneic kidney transplantation may be mediated by repression of effector cells by a specific subset of T-cells: the CD4+CD25bright+FoxP3+regulatory T-cells (Tregs). Here, we examined the suppressive capacity of Tregs isolated from the leukafereses product of 6 kidney transplant recipients, by reconstituting Tregs to responder T-cells at several time-points after initiation of proliferation. We show that Tregs derived from kidney transplant patients potently restrain proliferation to donor-antigens and 3rd party-antigens in classic reconstitution assays (i.e. addition of Tregs at the start of the co-incubation). However, when Tregs were added 5 days after initiation of proliferation, they were still capable of suppressing proliferation to donor-antigens (by 38%) but no longer to 3rd party-antigens. Thus, we conclude that the potency of Tregs to suppress reactivity to specific antigens should be determined by reconstitution to ongoing reactions.

Laparoscopic donor nephrectomy in obese donors: Easier to implement in overweight women? (Article)

2007-11-01T00:00:00Z

Laparoscopic donor nephrectomy (LDN) has been proven feasible in overweight individuals, but remains technically challenging. As the perirenal fat distribution and consistency significantly differ between men and women, we investigated possible differences between the genders. Prospectively collected data of 37 female and 39 male donors with a body mass index (BMI) over 27 who underwent total LDN were compared. Ninety-one donors with a BMI <25 served as controls. Clinically relevant differences were not observed between men and women of normal weight. In overweight donors, two (5%) procedures were converted to open in females and five (13%) in males. None of these conversions in females, but four conversions in males, appeared to be related to the donor's perirenal fat (P = 0.05). Operation time (median 210 vs. 241 min, P = 0.01) and blood loss (median 100 vs. 200 ml, P = 0.04) were favorable in female donors. The number of complications did not significantly differ. Total LDN in overweight female donors does not lead to increased operation times, morbidity or technical complications. In contrast, the outcome in obese males seems to be less advantageous, indicating that total LDN in overweight women can be advocated as a routine procedure but in obese men reluctance seems justified.

Psychological barriers for living kidney donation: How to inform the potential donors? (Article)

2007-10-01T00:00:00Z

BACKGROUND. This is the first large-scale interview study carried out in patients and potential donors who seem unwilling or unable to pursue living kidney donation. By investigating these groups, we explored whether further expansion of the living kidney donation program is feasible. METHODS. We interviewed 91 patients on the waiting list for a kidney transplant who did not pursue living kidney donation and their potential donors (n=53). We also included a comparison group. All respondents underwent an in-depth interview by a psychologist about topics that could influence their willingness to pursue living kidney donation. RESULTS. A total of 78% of the patients on the waiting list were willing to accept the offer of a living donor. The main reason for not pursuing living kidney donation was reluctance to discuss the issue with the potential donors. This was also found in the comparison group. Both groups indicated that if there was no donor offer, they tended to interpret this as a refusal to donate. This interpretation not always holds: more than one third (19 of 53) of the potential donors were open to consider themselves as a potential donor. On the other hand, a comparably sized group of potential donors (21 of 53) was reluctant about donation. The main reason for donor reluctance was fear for their health after donation. CONCLUSION. The majority of patients on the waiting list are willing to accept a living kidney donor, but adopt an awaiting attitude towards their potential donors. Offering those patients professional assistance should be considered.

Increasing incidence of severe encapsulating peritoneal sclerosis after kidney transplantation [10] (Article)

2007-08-01T00:00:00Z

Human heart, spleen, and perirenal fat-derived mesenchymal stem cells have immunomodulatory capacities (Article)

2007-08-01T00:00:00Z

Mesenchymal stem cells (MSCs) have important tissue repair functions and show potent immunosuppressive capacities in vitro. Although usually isolated from the bone marrow, MSCs have been identified in other tissues, including the skin and liver. In the present study, we isolated and characterized MSCs from human heart, spleen, and perirenal adipose tissue. MSCs from these different tissue sites were similar to those derived from bone marrow in that they expressed comparable levels of the cell-surface markers CD90, CD105, CD166, and HLA class I, were negative for CD34, CD45, HLA class II, CD80, and CD86 expression, and were capable of osteogenic and adipogenic differentiation. Like bone marrow-derived MSCs, MSCs from these different tissue sources inhibited the proliferation of alloactivated peripheral blood mononuclear cells (PBMCs), giving 85%, 79%, 79%, and 81% inhibition, respectively. Also in line with bone marrow-derived MSCs they inhibited proliferative responses of PBMCs to phytohemagglutinin, a nonspecific stimulator of lymphocyte proliferation, and reduced-memory T lymphocyte responses to tetanus toxoid. The results of this study demonstrate that MSCs from various tissues have similar immunophenotypes, in vitro immunosuppressive properties, and differentiation potential.

Interleukin-21: An interleukin-2 dependent player in rejection processes (Article)

2007-06-01T00:00:00Z

BACKGROUND. Interleukin (IL)-21 is the most recently described cytokine that signals via the common cytokine receptor (γc), is produced by activated CD4+ T-cells, and regulates expansion and effector function of CD8+ T-cells. MATERIALS. To explore the actions of IL-21 with other γc-dependent cytokines in alloreactivity, mRNA expression of IL-21, IL-21R α-chain, and IL-2 proliferation and cytotoxicity was measured after stimulation in mixed lymphocyte reactions. Additionally, IL-21 and IL-21R α-chain expression was studied in biopsies of heart transplant patients. RESULTS. Analysis of mRNA expression levels of allostimulated T-cells showed a 10-fold induction of IL-21 and IL-21R α-chain. Interestingly, induction of IL-21 was highly dependent on IL-2 (as in the presence of anti-IL-2, anti-IL-2R α-chain, and the immunosuppressive drugs cyclosporine A, tacrolimus, and rapamycin) the transcription of IL-21 was almost completely inhibited, whereas in the presence of exogenous IL-2 the mRNA expression of IL-21 was even more upregulated. IL-21 functioned as a costimulator for IL-2 to augment proliferation and cytotoxic responses, while blockade of the IL-2 route abrogated these functions of IL-21. Blockade of the IL-21 route by anti-IL-21R α-chain monoclonal antibodies inhibited the proliferation of alloactivated T-cells. Also, in vivo alloreactivity was associated with IL-21/IL-21R α-chain expression. After heart transplantation, the highest intragraft IL-21, IL-21R α-chain, and IL-2 mRNA expression levels were measured during acute rejection (P<0.001, P=0.01, P=0.03). CONCLUSION. IL-21 is a critical cytokine for IL-2 dependent immune processes. Blockade of the IL-21 pathway may provide a new perspective for the treatment of allogeneic responses in patients after transplantation.

Cost effectiveness of laparoscopic versus mini-incision open donor nephrectomy: A randomized study (Article)

2007-06-01T00:00:00Z

BACKGROUND. Cost-effectiveness remains an issue surrounding the introduction of laparoscopic donor nephrectomy (LDN). METHODS. In a randomized controlled trial the cost-effectiveness of LDN versus mini-incision open donor nephrectomy (ODN) was determined. Fifty donors were included in each group. All in-hospital costs were documented. Postoperatively, case record forms were sent to the donors during 1-year follow-up to record return-to-work and societal costs. To offset costs against quality of life, the Euroqol-5D questionnaire was administered preoperatively and 3, 7, 14, 28, 90, 180, and 365 days postoperatively. RESULTS. Mean total costs were €6,090 (US$7,308) after LDN and €4,818 ($5,782) after ODN (P<0.001). Disposables influenced the cost difference most. Mean productivity loss was 68 and 75 days after LDN and ODN respectively, corresponding to €783 ($940) gained per donor after LDN. The main gain in quality of life in the LDN group was realized within 4 weeks postoperatively. LDN resulted in a mean gain of 0.03 quality-adjusted life years at mean costs of €1,271 ($1,525) and €488 ($586) from a healthcare perspective and a societal perspective, respectively. This implies that one additional Quality-Adjusted Life Year after LDN costs about €16,000 ($19,200) from a societal point of view and about €41,000 ($49,200) from a health-care perspective. Activities other than work were resumed significantly earlier after LDN (66 vs. 91 days, P=0.01). CONCLUSION. In addition to a clinically relevant donor-experienced benefit from LDN, this technique appeared, given a societal perspective, a cost-efficient procedure mainly due to less productivity losses.

Intragraft FOXP3 mRNA expression reflects antidonor immune reactivity in cardiac allograft patients (Article)

2007-06-01T00:00:00Z

BACKGROUND. Regulatory FOXP3+ T cells control immune responses of effector T cells. However, whether these cells regulate antidonor responses in the graft of cardiac allograft patients is unknown. Therefore, we analyzed the gene expression profiles of regulatory and effector T-cell markers during immunological quiescence and acute rejection. METHODS. Quantitative real-time polymerase chain reaction was used to analyze mRNA expression levels in time-zero specimens (n=24) and endomyocardial biopsies (EMB; n=72) of cardiac allograft patients who remained free from rejection (nonrejectors; n=12) and patients with at least one histologically proven acute rejection episode (rejectors; International Society for Heart and Lung Transplantation [ISHLT] rejection grade >2; n=12). RESULTS. For all analyzed regulatory and effector T-cell markers, mRNA expression levels were increased in biopsies taken after heart transplantation compared with those in time-zero specimens. Posttransplantation, the FOXP3 mRNA levels were higher in EMB assigned to a higher ISHLT rejection grade than the biopsies with grade 0: the highest mRNA levels were detected in the rejection biopsies (rejection grade >2; P=0.003). In addition, the mRNA levels of CD25, glucocorticoid-induced TNF receptor family-related gene, cytotoxic T lymphocyte-associated antigen 4, interleukin-2, and granzyme B were also significantly higher in rejecting EMB than in nonrejecting EMB (rejection grade ≤2). This increase in expression levels in relation to the histological rejection grade was only observed in patients who developed an acute rejection episode; the mRNA levels of nonrejectors remained stable irrespective of ISHLT rejection grade. CONCLUSIONS. These observations suggest that, after clinical heart transplantation, FOXP3+ T cells do not prevent acute rejection, but rather are a response to antidonor effector T-cell activity.

Decreased antigen-specific T-cell proliferation by moDC among hepatitis B vaccine non-responders on haemodialysis (Article)

2007-06-01T00:00:00Z

Patients with end-stage kidney disease, whether or not on renal replacement therapy, have an impaired immune system. This is clinically manifested by a large percentage of patients unresponsive to the standard vaccination procedure for hepatitis B virus (HBV). In this study, the immune response to HBV vaccination is related to the in vitro function of monocyte-derived dendritic cells (moDC). We demonstrate that mature moDC from nonresponders to HBV vaccination have a less mature phenotype, compared to responders and healthy volunteers, although this did not affect their allostimulatory capacity. However, proliferation of autologous T cells in the presence of tetanus toxoid and candida antigen was decreased in non-responders. Also, HLA-matched CD4+ hsp65-specific human T-cell clones showed markedly decreased proliferation in the group of non-responders. Our results indicate that impairment of moDC to stimulate antigen-specific T cells provides an explanation for the clinical immunodeficiency of patients with end-stage kidney disease.

The implementation of a kidney exchange program does not induce a need for additional psychosocial support (Article)

2007-05-01T00:00:00Z

The Dutch kidney exchange donation program started in January 2004. A literature review has shown that several factors of the exchange program could influence the psychological well being of participants, such as the loss of the possibility of a 'medical excuse' for unwilling donors and the issue of anonymity. However, these factors have not been the subject of empirical study yet. We therefore studied these factors to determine whether additional psychosocial support is necessary for donors and recipients in the Dutch kidney exchange program. We used structured interviews for all 48 donors and recipients that had undergone exchange donation/transplantation in 2004. A psychologist interviewed the participants before and 3 months after transplantation. We included a comparison group of 48 donors and recipients participating in the regular living kidney donation program. Donors did not experience additional pressure to donate due to the exchange donation. Most participants (69%) preferred anonymity between the couples. Ten percentage needed additional emotional support. In this respect the exchange group did not differ from the comparison group. We conclude that the psychosocial support offered to exchange couples can be comparable with the support normally offered to participants in the regular living kidney donation program.

Peripheral blood manipulation significantly affects the result of dendritic cell monitoring (Article)

2007-04-01T00:00:00Z

It has been postulated that the plasmacytoid/myeloid dendritic cell ratio (pDC/mDC) reflects immune reactivity, and can therefore be used to monitor transplant recipients. We investigated the influence of Ficoll-Paque separation and PBMC cryopreservation on the pDC/mDC ratio and the expression of maturation markers, e.g. chemokine receptors (CKRs) CCR7, CXCR4, and CCR5, in comparison to fresh blood cells. Fractions of pDCs and mDCs, and CKR expression were measured by flow cytometry in fresh blood, in Ficoll-isolated PBMCs and in cryopreserved PBMCs from healthy individuals and kidney transplant recipients. Ficoll-isolation of PBMCs resulted in higher pDC/mDC ratios in both groups compared to fresh blood cells resulting from a relatively large increase in pDCs compared to mDCs. The pDC/mDC ratio increased further after cryopreservation of PBMCs from kidney transplant recipients. Ficoll-isolation and cryopreservation of PBMCs affected the proportion of mDCs and pDCs positive for CKRs, and their expression levels resulting in a more mature phenotype. In conclusion, the pDC/mDC ratio and pDC or mDC maturation status based on CKR expression, is dependent on manipulation of PBMCs. Therefore, fresh blood is preferable for monitoring purposes in transplant patients, as only these cells reflect the in vivo immune-status of patients accurately.

Stable T-cell reactivity after successful tapering of azathioprine in HLA-identical living-related kidney transplant recipients despite minor histocompatibility antigen mismatches (Article)

2007-02-01T00:00:00Z

Background. Human leukocyte antigen (HLA)-identical living-related (LR) kidney transplant recipients often receive the standard regimen of immunosuppression. We wondered whether these patients should be exposed to the side effects of these drugs any longer. Safe tapering of immunosuppression should not result in rejection and high donor-directed T-cell responses. In the present study, we investigated the effect of tapering azathioprine (AZA) on T-cell reactivity. Methods. Fifteen HLA-identical LR kidney transplant recipients receiving a median of 150 mg/day AZA and 5-10 mg/day prednisone were tapered to a median of 50 mg/day AZA. Donor-, third-party and tetanus toxoid (TET)-reactivity were determined in interferon (IFN)-γ and interleukin (IL)-13 Elispot assays, which reflect the T-helper (Th)1 and T-helper (Th)2 response. Results. After the tapering of AZA, none of the patients developed acute rejection and the renal function remained stable, even at 1-year follow-up. The frequency of donor-specific IFN-γ and IL-13 producing cells (pc) was low. Tapering of AZA did not influence the frequency of both IFN-γ and IL-13 pc. Also, the reactivity against third-party cells and TET remained unchanged. Conclusions. The AZA-dose can be safely reduced in recipients of an HLA-identical LR kidney transplant without affecting kidney function and without increasing T-cell responses directed against donor or other antigens.

Functional impairment of monocyte-derived dendritic cells in patients with severe chronic kidney disease (Article)

2007-01-01T00:00:00Z

Background. Dendritic cells (DCs) are antigen-presenting cells that are pivotal for the initiation of the primary immune response. Patients with chronic kidney disease (CKD) with or without chronic intermittent haemodialysis (CIHD) show an impaired immune response. Dysfunction of DCs may underlie this phenomenon. Methods. In this study, several different functions of monocyte-derived DCs (moDC) of patients with CKD class IV-V (glomerular filtration rate <30 ml/min) and patients on CIHD were studied in vitro and compared with age- and sex-matched healthy volunteers. Results. We demonstrate that, independent of the maturation stimulus used, mature moDC from both groups of patients did not acquire the same level of terminal differentiation as moDC from controls, as shown by analysis of cell surface markers and the relative high macropinocytosis activity of moDC. The stimulation of allogeneic T-cells by immature moDC and mature moDC did not differ between patients and controls. However, in the presence of immature moDC or antigen-loaded maturated moDC from patients, less proliferation of autologous T-cells was observed in response to recall antigens. There was no difference between moDC from controls and patients in their ability to activate naive T-cells and to differentiate them into Th1 and Th2 cells. Conclusions. These results show that the terminal differentiation of moDC in patients with severe CKD is impaired. This impairment is not restricted to one maturation stimulus and is independent of treatment with haemodialysis.

Functional CD25bright+ alloresponsive T cells in fully immunosuppressed renal allograft recipients (Article)

2007-01-01T00:00:00Z

Background: Evidence from animal studies indicate a crucial role for CD25bright+regulatory T cells in transplantation tolerance. Methods: To assess whether peripheral CD25bright+T cells control immune responses in immunosuppressed kidney transplant patients, we analyzed the suppressive capacities of these cells using mixed lymphocytes reactions. Results: Allogeneic stimulation of patients peripheral blood mononuclear cells was associated with IL-2 production and T-cell proliferation. Depletion of CD25bright+T cells resulted in a 35% (median) higher IL-2 production and a 38% higher proliferative response against third party cells, showing that functional regulatory CD25bright+T cells were present (p = 0.03 and 0.02 respectively). In eight out of 11 patients, we also demonstrated regulation activity against donor-activated T cells (p = 0.03). These data were confirmed in coculture experiments with isolated CD25-/dimT cells plus CD25bright+T cells. At a 1:2 ratio, the CD25bright+T cells suppressed the proliferation of CD25-/dimdonor- and third party-stimulated responder T cells. Conclusions: CD25bright+T cells with immune regulatory activities against anti-donor-responsive T cells are readily detectable in renal allograft recipients during treatment with full dosage immunosuppression. Whether CD25bright+T cells indeed play a role in graft acceptance after organ transplantation in patients remains to be elucidated.

Living Kidney Donation: Psychological and Ethical Aspects (Internal Report)

2006-08-01T00:00:00Z

DOELSTELLING Nierdonatie bij leven levert medisch en maatschappelijk gezien veel voordelen op, maar toch willen of kunnen niet alle nierpatiënten op de wachtlijst en/of hun naasten zich opgeven voor het nierdonatie bij leven programma. De doelstelling van het project ‘Nierdonatie bij leven: psychologische en ethische aspecten’ is het verkrijgen van meer inzicht in de kennis en acceptatie van nierdonatie bij leven. Het gaat hierbij om kennis en acceptatie onder proefpersonen die daadwerkelijk in aanmerking komen voor nierdonatie/ transplantatie bij leven, dat wil zeggen (1) patiënten met eindfase nierfalen op de wachtlijst voor een niertransplantatie en (2) de mensen uit hun omgeving; de potentiële donoren. Het benaderen van deze groepen is de strategie om uit te vinden of, en onder welke voorwaarden, uitbreiding van het nierdonatie bij leven programma praktisch haalbaar en ethisch verdedigbaar is. VRAAGSTELLINGEN Het project omvat twee vraagstellingen. De eerste vraagstelling is: wat zijn de psychologische barrières voor nierdonatie bij leven voor patiënten op de wachtlijst, en de mensen uit hun omgeving? De tweede vraagstelling luidt: wat zijn de morele argumenten om de patiënt en de mensen uit de omgeving van de patiënt (de potentiële donoren) al dan niet actief te benaderen over nierdonatie bij leven? In andere woorden; in hoeverre zijn interventies ethisch verdedigbaar? OPZET PATIËNTEN EN (POTENTIËLE) DONOREN Wij hebben allereerst de groep patiënten die op de wachtlijst voor niertransplantatie staat benaderd (regio Erasmus MC). Aan de patiënt vragen wij toestemming om ook de potentiële donoren uit zijn of haar omgeving te benaderen. Indien beiden hiermee instemmen, vindt het interview met deze potentiële donor plaats. Voor deze studie hebben we tevens een controlegroep benaderd. In de controlegroep zitten patiënten en donoren die nog geen familietransplantatie hebben ondergaan, maar die wel al hebben besloten door te gaan met de donatie bij leven procedure en dit met hun artsen hebben overlegd. INTERVIEW Alle deelnemers aan ons onderzoek zijn geïnterviewd middels een semi-gestructureerd interview. Voorafgaand onderzoek heeft aangetoond dat een aantal factoren een rol kan spelen bij het niet kunnen of willen ondergaan van nierdonatie bij leven. Deze factoren komen terug in de interviews: · Demografische en medische variabelen · Kennis en informatie · Standpunten en argumenten ten aanzien van nierdonatie bij leven, · Communicatie met de arts en de omgeving · Risicoperceptie · Verwachtingen ten aanzien van de gevolgen voor de persoonlijke relatie tussen donor en ontvanger. ETHISCHE ANALYSE De resultaten van de empirische gedeelte van deze studie dienen als basis voor de ethische analyse. Argumenten zoals gevonden in het empirische gedeelte van de studie worden getoetst op houdbaarheid met behulp van ethische theorieën over de structuur van argumenten.,Wij hebben met name gebruik gemaakt van de theorien zoals die geformuleerd zijn door Toulmin, Rawls en Nagel. BEREIKTE RESULTATEN/NIEUWE INZICHTEN De bereidheid om een nier van iemand in de naaste omgeving te accepteren is zeer hoog voor de patiënten in de onderzoeksgroep: slecht 19% is negatief over donatie bij leven. Het is dus niet zo dat de patiënt in het algemeen niet zou willen. Voor een aantal variabelen vonden we verschillen tussen de onderzoeksgroep en de controlegroep. Een opvallende uitkomst is dat in vrijwel àlle gevallen in de controle groep de communicatie over de donatie gestart wordt vanuit de donor: het al dan niet aangeboden krijgen van een nier lijkt bepalend voor het doorgaan van de (levende donor) transplantatie. Patiënten vinden het erg moeilijk om uit zichzelf over het onderwerp te beginnen. Ethische analyse laat zien dat de argumenten en bezwaren tegen nierdonatie bij leven zoals gevonden in de onderzoeksgroep weerlegbaar zijn. Dit gegeven draagt bij aan de rechtvaardiging van interventies in de situatie van patiënten op de wachtlijst voor transplantatie die zich in eerste instantie niet aanmelden voor het nierdonatie bij leven programma.

De Behoefte aan Psychosociale Steun bij Deelnemers aan het Nederlandse Cross-over Transplantatie Programma (Research Paper)

2006-06-01T00:00:00Z

Final technical report of the project.

Comparison of laparoscopic and mini incision open donor nephrectomy: single blind, randomised controlled clinical trial (Article)

2006-01-01T00:00:00Z

OBJECTIVES: To determine the best approach for live donor nephrectomy to minimise discomfort to the donor and to provide good graft function. DESIGN: Single blind, randomised controlled trial. SETTING: Two university medical centres, the Netherlands. PARTICIPANTS: 100 living kidney donors. INTERVENTIONS: Participants were randomly assigned to either laparoscopic donor nephrectomy or to mini incision muscle splitting open donor nephrectomy. MAIN OUTCOME MEASURES: The primary outcome was physical fatigue using the multidimensional fatigue inventory 20 (MFI-20). Secondary outcomes were physical function using the SF-36, hospital stay after surgery, pain, operating times, recipient graft function, and graft survival. RESULTS: Conversions did not occur. Compared with mini incision open donor nephrectomy, laparoscopic donor nephrectomy resulted in longer skin to skin time (median 221 v 164 minutes, P < 0.001), longer warm ischaemia time (6 v 3 minutes, P < 0.001), less blood loss (100 v 240 ml, P < 0.001), and a similar number of complications (intraoperatively 12% v 6%, P = 0.49, postoperatively both 6%). After laparoscopic nephrectomy, donors required less morphine (16 v 25 mg, P = 0.005) and shorter hospital stay (3 v 4 days, P = 0.003). During one year's follow-up mean physical fatigue was less (difference - 1.3, 95% confidence interval - 2.4 to - 0.1) and physical function was better (difference 6.2, 2.0 to 10.3) after laparoscopic nephrectomy. Function of the graft and graft survival rate of the recipient at one year censored for death did not differ (100% after laparoscopic nephrectomy and 98% after open nephrectomy). CONCLUSIONS: Laparoscopic donor nephrectomy results in a better quality of life compared with mini incision open donor nephrectomy but equal safety and graft function.

Mens (dood of levend) of dier? Attitudes over en morele implicaties van orgaanverwerving (Research Paper)

2004-08-02T00:00:00Z

Dit rapport is het verslag van een verkennende studie naar attitudes met betrekking tot orgaandonatie, en de morele implicaties hiervan. Psychologisch en ethisch onderzoek vullen elkaar in dit rapport aan. Er wordt aandacht geschonken aan twee ontwikkelingen op het gebied van orgaanverwerving: de toename van orgaandonaties bij leven, met name bij donatie van nieren en de verminderde interesse in de ontwikkeling van xenotransplantatie. Het psychologische deel van het rapport valt uiteen in literatuurstudie en eigen empirisch onderzoek. In dit deel wordt zowel de attitude van patiënten als de psychosociale belasting beschreven voor xenotransplantatie en voor nierdonatie bij leven. Patiënten zien nierdonatie bij leven in het algemeen als een wenselijk alternatief voor de wachtlijstsituatie, terwijl men in dit opzicht een stuk terughoudender is ten aanzien van xenotransplantatie. Om te bepalen welke rol van overheid, zorgverleners en onderzoekers gepast is, is het van belang te begrijpen hoe persoonlijke overtuigingen worden gevormd en kunnen veranderen. In het ethische, tweede deel van het rapport wordt dan ook meer aandacht besteed aan de verschillende motivaties voor orgaandonatie. Bij postmortale donatie worden vooral waarden als vrijwilligheid, anonimiteit en altruïsme genoemd. Bij familiedonatie doen begrippen als vanzelfsprekende solidariteit, morele plicht en lotsverbondenheid hun intrede, maar ook begrippen als eigenbelang, afhankelijkheid en wederkerigheid. Onderzocht wordt hoe de verschillende donatievormen zich tot elkaar verhouden, teneinde te bepalen op welke motivaties voor orgaandonatie we als maatschappij een beroep willen doen. Op dit punt wordt expliciet ingegaan op de rol van de overheid. Tevens is er een meer losstaand hoofdstuk gewijd aan commerciële orgaandonatie.

Tapering immunosuppression in recipients of living donor kidney transplants. (Article)

2004-07-01T00:00:00Z

We have previously suggested that the in vitro donor-specific cytotoxic T-lymphocyte precursor (CTLp) assay can guide us to identify patients in which the immunosuppressive load can be tapered. In a clinical trial we had observed that a low (<10/10(6) PBMC) frequency of these CTLp was predictive for an uneventful rejection-free clinical course in patients that were converted from calcineurin inhibitors to mycophenolate mofetil or azathiopine. In the present prospective study in 81 stable kidney transplant recipients, already converted from calcineurin inhibitors, we measured CTLp frequencies and reduced the immunosuppressive load on a routine basis when CTLp were <10/10(6) PBMC. Donor-specific cytotoxicity could not be measured in 50/81 patients, while their reactivity against third-party lymphocytes was not impaired. These 50 patients were tapered in their immunosuppression. Only in one patient, who had stopped all his medication, was a rejection episode diagnosed. We conclude that in patients with a low donor-specific CTLp frequency it is safe to reduce the immunosuppression.

Living renal donors: optimizing the imaging strategy--decision- and cost-effectiveness analysis (Article)

2003-01-01T00:00:00Z

PURPOSE: To determine the most cost-effective strategy for preoperative imaging performed in potential living renal donors. MATERIALS AND METHODS: In a decision-analytic model, the societal cost-effectiveness of digital subtraction angiography (DSA), gadolinium-enhanced magnetic resonance (MR) angiography, contrast material-enhanced spiral computed tomographic (CT) angiography, and combinations of these imaging techniques was evaluated. Outcome measures included lifetime cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. A base-case analysis was performed with a 40-year-old female donor and a 40-year-old female recipient. RESULTS: For the donor, MR angiography (24.05 QALYs and 9,000 dollars) dominated all strategies except for MR angiography with CT angiography, which had an incremental ratio of 245,000 dollars per QALY. For the recipient, DSA and DSA with MR angiography yielded similar results (10.46 QALYs and 179,000 dollars) and dominated all other strategies. When results for donor and recipient were combined, DSA dominated all other strategies (34.51 QALYs and 188,000 dollars). If DSA was associated with a 99% specificity or less for detection of renal disease, MR angiography with CT angiography was superior (34.47 QALYs and 190,000 dollars). CONCLUSION: For preoperative imaging in a potential renal donor, DSA is the most cost-effective strategy if it has a specificity greater than 99% for detection of renal disease; otherwise, MR angiography with CT angiography is the most cost-effective strategy.

Preload dependence of new Doppler techniques limits their utility for left ventricular diastolic function assessment in hemodialysis patients (Article)

2003-01-01T00:00:00Z

Left ventricular (LV) hypertrophy leads to diastolic dysfunction. Standard Doppler transmitral and pulmonary vein (PV) flow velocity measurements are preload dependent. New techniques such as mitral annulus velocity by Doppler tissue imaging (DTI) and LV inflow propagation velocity measured from color M-mode have been proposed as relatively preload-independent measurements of diastolic function. These parameters were studied before and after hemodialysis (HD) with ultrafiltration to test their potential advantage for LV diastolic function assessment in HD patients. Ten patients (seven with LV hypertrophy) underwent Doppler echocardiography 1 h before, 1 h after, and 1 d after HD. Early (E) and atrial (A) peak transmitral flow velocities, peak PV systolic (s) and diastolic (d) flow velocities, peak e and a mitral annulus velocities in DTI, and early diastolic LV flow propagation velocity (V(p)) were measured. In all patients, the E/A ratio after HD (0.54; 0.37 to 1.02) was lower (P < 0.01) than before HD (0.77; 0.60 to 1.34). E decreased (P < 0.01), whereas A did not. PV s/d after HD (2.15; 1.08 to 3.90) was higher (P < 0.01) than before HD (1.80; 1.25 to 2.68). Tissue e/a after HD (0.40; 0.26 to 0.96) was lower (P < 0.01) than before HD (0.56; 0.40 to 1.05). Tissue e decreased (P < 0.02), whereas a did not. V(p) after HD (30 cm/s; 16 to 47 cm/s) was lower (P < 0.01) than before HD (45 cm/s; 32 to 60 cm/s). Twenty-four hours after the initial measurements values for E/A (0.59; 0.37 to 1.23), PV s/d (1.85; 1.07 to 3.38), e/a (0.41; 0.27 to 1.06), and V(p) (28 cm/s; 23 to 33 cm/s) were similar as those taken 1 h after HD. It is concluded that, even when using the newer Doppler techniques DTI and color M-mode, pseudonormalization, which was due to volume overload before HD, resulted in underestimation of the degree of diastolic dysfunction. Therefore, the advantage of these techniques over conventional parameters for the assessment of LV diastolic function in HD patients is limited. Assessment of LV diastolic function should not be performed shortly before HD, and its time relation to HD is essential.

Differential expression of heme oxygenase-1 and vascular endothelial growth factor in cadaveric and living donor kidneys after ischemia-reperfusion (Article)

2003-01-01T00:00:00Z

The extent of graft damage after ischemia-reperfusion reflects the balance between deleterious events and protective factors. Heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) may contribute to cytoprotection by their anti-inflammatory and antiapoptotic properties. For investigating whether HO-1 and VEGF play a role in the adaptive response to ischemia-reperfusion injury after renal transplantation, kidney biopsies were analyzed from living (n = 45) and cadaveric (n = 16) donors, obtained at three time points: at the end of cold storage T(-1), after warm ischemia T(0), and after reperfusion T(+1). The mRNA expression levels of HO-1, VEGF(165), Bcl-2, Bax, and hypoxia inducible factor-1alpha were quantified by real-time reverse transcriptase-PCR, and the HO-1 and VEGF proteins were analyzed by immunohistochemistry. Cadaveric donor kidneys presented higher mRNA expression levels of hypoxia inducible factor-1alpha. In contrast, mRNA expression levels of HO-1, VEGF(165), and Bcl-2 were significantly lower in kidneys from cadaveric donors. Overall, a significant correlation was observed between mRNA expression of Bcl-2 and VEGF(165), between Bcl-2 and HO-1, and between HO-1 and VEGF(165). Moreover, protein expression of HO-1 and VEGF was detected in the same anatomical kidney compartments (glomerulus, arteries, and distal tubules). Renal function at the first week posttransplantation (analyzed by serum creatinine levels) showed a significant correlation with both HO-1 and VEGF mRNA expression, reinforcing the protective role of both genes in the early events of transplantation. It is concluded that the lower expression of HO-1, VEGF(165), and Bcl-2 in cadaveric donor kidneys can reflect a defective adaptation against ischemia-reperfusion injury that may affect their function in the short term.

Yersinia pseudotuberculosis bacteraemia in a kidney transplant patient (Article)

2002-01-01T00:00:00Z

Intragraft interleukin 2 mRNA expression during acute cellular rejection and left ventricular total wall thickness after heart transplantation (Article)

2002-01-01T00:00:00Z

OBJECTIVE: To assess whether diastolic graft function is influenced by intragraft interleukin 2 (IL-2) messenger RNA (mRNA) expression in rejecting cardiac allografts. DESIGN: 16 recipients of cardiac allografts were monitored during the first three months after transplantation. The presence of IL-2 mRNA in endomyocardial biopsies (n = 123) was measured by reverse transcriptase polymerase chain reaction. To determine heart function, concurrent M mode and two dimensional Doppler echocardiograms were analysed. RESULTS: Histological signs of acute rejection (International Society for Heart and Lung Transplantation (ISHLT) rejection grade > 2) were strongly associated with IL-2 mRNA expression (IL-2 mRNA was present in 12 of 20 endomyocardial biopsies (60%) with acute rejection and in 24 of 103 endomyocardial biopsies (23%) without acute rejection, p = 0.002). No significant relation was found between either histology or IL-2 mRNA expression alone and the studied echocardiographic parameters. However, stratification of the echocardiographic data into those of patients with and those without acute rejection showed that during acute rejection IL-2 mRNA expression was significantly associated with increased left ventricular total wall thickness (mean change in total wall thickness was +0.22 cm in patients with IL-2 mRNA expression versus -0.18 cm in patients without IL-2 mRNA expression, p = 0.048). CONCLUSIONS: An increase in left ventricular total wall thickness precedes IL-2 positive acute rejection after heart transplantation. Thus, cardiac allograft rejection accompanied by intragraft IL-2 mRNA expression may be indicative of more severe rejection episodes.

Withdrawal of cyclosporine or prednisone six months after kidney transplantation in patients on triple drug therapy: a randomized, prospective, multicenter study (Article)

2002-01-01T00:00:00Z

Uncertainty exists regarding the necessity of continuing triple therapy consisting of mycophenolate mofetil (MMF), cyclosporine (CsA), and prednisone (Pred) after kidney transplantation (RTx). At 6 mo after RTx, 212 patients were randomized to stop CsA (n = 63), stop Pred (n = 76), or continue triple drug therapy (n = 73). The MMF dose was 1000 mg twice daily, target CsA trough levels were 150 ng/ml, and Pred dose was 0.10 mg/kg per d. Follow-up was until 24 mo after RTx. Biopsy-proven acute rejection occurred in 14 (22%) of 63 patients after CsA withdrawal compared with 3 (4%) of 76 in the Pred withdrawal group (P = 0.001) and 1 (1.4%) of 73 in the control group (P = 0.0001). Biopsy-proven chronic rejection was present in one patient in the control group, in nine patients after CsA withdrawal (P = 0.006 versus control group); and in four patients after discontinuation of Pred (NS). Graft loss occurred in two versus one patient after CsA or Pred withdrawal, respectively, and in two patients in the control group (NS). Patients who successfully withdrew CsA had a significantly lower serum creatinine during follow-up. Pred withdrawal resulted in a reduction in mean arterial pressure, and the total cholesterol/HDL ratio increased. In conclusion, rapid CsA withdrawal at 6 mo after RTx results in a significantly increased incidence of biopsy-proven acute and chronic rejection. Pred withdrawal was safe and resulted in a reduction in mean arterial pressure. However, patient and graft survival and renal function 2 yr after RTx were not different among groups.

Specific effect of the infusion of glucose on blood volume during haemodialysis (Article)

2002-01-01T00:00:00Z

BACKGROUND: Intradialytic morbid events such as hypotension and cramps during haemodialysis are generally treated by infusion of iso- or hypertonic solutions. However, differences may exist between solutions with respect to plasma refilling and vascular reactivity. METHODS: We compared the effect of no infusion (NI) with isovolumetric infusion of isotonic saline 0.9% (IS), saline 3% (HS), isotonic glucose 5% (IG), glucose 20% (HG) and mannitol 20% (HM), in six patients during the first hour of six standardized haemodialysis sessions with ultrafiltration. Relative blood volume was monitored continuously by measurement of the intravascular amount of protein. Blood pressure was measured by an oscillometric method, while cardiac output was measured by a thoracic impedance technique. RESULTS: At baseline, no differences in serum urea, sodium, potassium, glucose and osmolarity were found between the various infusion experiments. The maximum increase in relative blood volume directly after infusion was significantly greater with HG (5.1+/-0.7%) than with all other infusions (P<0.05). Stroke volume increased (21.0+/-19.2%, P<0.05) and total peripheral resistance decreased significantly (15.4+/-16.4%, P<0.05) after HG infusions. CONCLUSIONS: Infusion of hypertonic glucose during dialysis results in a greater increase in relative blood volume (RBV) than equal volumes of other solutions. As mannitol has the same osmolarity, molecule mass and charge, the greater increase in RBV following hypertonic glucose appears to be a specific effect, possibly related to a decline in vascular tone. It is therefore uncertain whether the observed increase in plasma volume during hypertonic glucose infusions will be of clinical benefit.

Impact of intraoperative donor management on short-term renal function after laparoscopic donor nephrectomy (Article)

2002-01-01T00:00:00Z

OBJECTIVE: To determine whether intraoperative diuresis, postoperative recovery, and early graft function differ between laparoscopic open nephrectomy (LDN) and open donor nephrectomy (ODN). SUMMARY BACKGROUND DATA: Laparoscopic donor nephrectomy can reduce donor complications in terms of decreased pain and shorter convalescence. Although its technical feasibility has been established, concerns have been raised about the impaired renal function resulting from pneumoperitoneum and short- and long-term function of kidneys removed by LDN. METHODS: Between December 1997 and December 2000, 89 LDNs were performed at the authors' institution. These were compared with 83 conventional ODNs performed between January 1994 and December 1997. Graft function, intraoperative variables, and clinical outcome were compared. RESULTS: Laparoscopic donor nephrectomy was attempted in 89 patients and completed in 91% (81/89). Length of hospital stay was significantly shorter in the laparoscopic group. During kidney dissection, the amount of fluids administered and intraoperative diuresis were significantly lower for LDN. In recipients, mean serum creatinine was higher after LDN compared with ODN 1 day after surgery. From postoperative days 2 until 28, there were no differences in serum creatinine. Graft survival rates were similar for LDN and ODN. CONCLUSIONS: Donors can benefit from an improvement in postoperative recovery after LDN. Assessment of an adequate perioperative hydration protocol is mandatory to ensure optimal kidney quality during laparoscopic procurement. The initial graft survival and function rates justify continued development and adoption of LDN.

Quantitative flow cytometry shows activation of the TNF-alpha system but not of the IL-2 system at the single cell level in renal replacement therapy (Article)

2001-01-01T00:00:00Z

BACKGROUND: Immunological dysfunction in patients on haemodialysis may be related to imbalanced cytokine systems, such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-2. Despite activation of these systems, haemodialysis patients show high susceptibility for infections and malignancies, and have a poor immunological reaction to T-cell-dependent antigens, like hepatitis B vaccination. In this study we have determined the activation status of the two different cytokine systems, at the single cell level, using quantitative flow cytometry. METHODS: Using fluorescein isothiocyanate- or phycoerythrin-conjugated antibodies directed against TNF-R2 (CD120b), IL-2Ralpha (CD25) and IL-2Rbeta (CD122), we measured the expression of these receptors at the single cell level in order to determine the level of activation of monocytes and T-lymphocytes. RESULTS: Significantly higher expression of the TNF-alpha receptor, TNF-R2, was present on both monocytes and T-lymphocytes in patients on renal replacement therapy (RRT) compared with pre-dialysis chronic renal failure (CRF) patients and controls, indicating activation of the TNF-alpha system. In contrast, IL-2R expression was comparable in all groups studied, which may reflect a non-activated state of the IL-2 system. CONCLUSIONS: The present study illustrates an activated state of the TNF-alpha system in patients on RRT, at the single cell level, while the IL-2 system seems to be unaffected. These findings support the hypothesis that the interaction between the TNF-alpha and IL-2 cytokine systems is disturbed.

Variability of relative blood volume during haemodialysis (Article)

2000-01-01T00:00:00Z

BACKGROUND: A decrease in blood volume is thought to play a role in dialysis-related hypotension. Changes in relative blood volume (RBV) can be assessed by means of continuous haematocrit measurement. We studied the variability of RBV changes, and the relation between RBV and ultrafiltration volume (UV), blood pressure, heart rate, and inferior caval vein (ICV) diameter. METHODS: In 10 patients on chronic haemodialysis, RBV measurement was performed during a total of one hundred 4-h haemodialysis sessions. Blood pressure and heart rate were measured at 5-min intervals. ICV diameter was assessed at the start and at the end of dialysis using ultrasonography. RESULTS: The changes in RBV showed considerable inter-individual variability. The average change in RBV ranged from -0.5 to -8.2% at 60 min and from -3.7 to -14.5% at 240 min (coefficient of variation (CV) 0.66 and 0.35 respectively). Intra-individual variability was also high (CV at 60 min 0.93; CV at 240 min 0.33). Inter-individual as well as intra-individual variability showed only minor improvement when RBV was corrected for UV. We found a significant correlation between RBV and UV at 60 (r= -0.69; P<0.001) and at 240 min (r= -0.63; P<0.001). There was a significant correlation between RBV and heart rate (r= -0.39; P<0.001), but not between RBV or UV and blood pressure. The level of RBV reduction at which hypotension occurred was also highly variable. ICV diameter decreased from 10.3+/-1.7 mm/m(2) to 7.3+/-1. 5 mm/m(2). There was only a slight, although significant, correlation between ICV diameter and RBV (r= -0.23; P<0.05). The change in ICV-diameter showed a wide variation. CONCLUSIONS: RBV changes during haemodialysis showed a considerable intra- and inter-individual variability that could not be explained by differences in UV. No correlation was observed between UV or changes in RBV and either blood pressure or the incidence of hypotension. Heart rate, however, was significantly correlated with RBV. Moreover, IVC diameter was only poorly correlated with RBV, suggesting a redistribution of blood towards the central venous compartment. These data indicate that RBV monitoring is of limited use in the prevention of dialysis-related hypotension, and that the critical level of reduction in RBV at which hypotension occurs depends on cardiovascular defence mechanisms such as sympathetic drive.

Mycophenolic acid plasma concentrations in kidney allograft recipients with or without cyclosporin: a cross-sectional study (Article)

1999-01-01T00:00:00Z

BACKGROUND: Combining cyclosporin (CsA) and prednisone with mycophenolate mofetil (MMF) results in a significant reduction in the rate of biopsy-proven acute rejection after kidney transplantation. This is achieved with a standard daily MMF dosage of 2 or 3 g. Whether monitoring of the pharmacologically active metabolite mycophenolic acid (MPA) will lead to improved safety and efficacy is unclear. METHODS: We monitored MPA trough levels in 18 kidney transplant recipients treated with CsA, prednisone, and MMF (63 samples) and in 11 patients (31 samples) treated with prednisone and MMF only, in a cross-sectional study. All patients were at least 3 months after transplantation with stable graft function. All patients were treated with 2 g MMF for at least 3 months and 10 mg prednisone. RESULTS: The MPA trough levels in the CsA-treated patients were significantly lower (P<0.0001; Mann-Whitney) than those in patients on MMF and prednisone only (mean MPA levels 1.98+/-0.12 vs 4.38+/-0.40 mg/l respectively). CONCLUSIONS: Although all patients were treated with an identical MMF dose, a significant difference was found in the MPA trough levels between CsA- vs non-CsA-treated patients. This suggests that CsA influences the MPA trough level. The level at which CsA affects the MPA trough levels is unclear.

The TNF-alpha system in heart failure and after heart transplantation: plasma protein levels, mRNA expression, soluble receptors and plasma buffer capacity (Article)

1999-01-01T00:00:00Z

BACKGROUND: The two soluble tumour necrosis factor (TNF) receptors (sTNF-R1, sTNF-R2) can bind TNF-alpha, which is a cytokine with cardiodepressant properties. In heart failure and after heart transplantation, the TNF-alpha system is unbalanced, due to elevated levels of sTNF receptors. AIM: To assess the activity of the TNF-alpha system in patients with heart failure and after heart transplantation. METHODS: We measured TNF-alpha mRNA expression of peripheral blood mononuclear cells, plasma levels of TNF-alpha and sTNF reverse transcriptase receptors, using polymerase chain reaction and ELISA and performed a TNF-alpha binding capacity analysis, quantitating the buffer capacity of patients' plasma. RESULTS: In 11 patients with heart failure and in 15 cardiac allograft recipients, the TNF-alpha mRNA expression was comparable to controls. This level of mRNA was not accompanied by detectable TNF-alpha plasma levels. Significantly higher sTNF receptors levels were found in patients: ( P <0.001; ANOVA). The TNF-alpha binding capacity of patients' plasma was significantly increased, which led to decreased TNF-alpha recovery ( P<0.05). Both sTNF receptors showed a linear correlation with serum creatinine (sTNF-RI: r=0.92; sTNF-R2: r=0.82, P<0.001). CONCLUSIONS:The TNF-alpha mRNA expression and plasma levels show that the 'peripheral' TNF-alpha system is not activated. The high sTNF-receptors levels and their elevated TNF-alpha binding capacity, resulting in decreased TNF-alpha bioavailability, may contribute to an immunosuppressed state in these patients.

Beneficial effects of conversion from cyclosporine to azathioprine on fibrinolysis in renal transplant recipients (Article)

1999-01-01T00:00:00Z

Cyclosporin A (CsA) has been implicated as one of the factors contributing to the high cardiovascular morbidity and mortality after renal transplantation. This may be mediated by either a high prevalence of conventional risk factors for atherosclerosis, such as hypertension, hypercholesterolemia, and diabetes mellitus, or by impairment of the fibrinolytic activity evoked by CsA, possibly through interference with prostanoid metabolism. We therefore assessed the impact of conversion of CsA to azathioprine immunosuppressive treatment on parameters of fibrinolytic activity and plasma concentration of the prostanoids prostaglandin E2 and thromboxane B2 in 18 stable renal transplant recipients. During CsA, mean arterial pressure and serum creatinine were significantly higher than during azathioprine (116+/-15 mm Hg versus 106+/-13 mm Hg, P=0.0003; and 147+/-34 micromol/L versus 127+/-35 micromol/L, P=0.002; mean+/-SD). On conversion, the plasma tissue plasminogen activator activity increased from 1.2 (1.1 to 1.7; median, 95% CI) to 1.8 (1.6 to 2.0) IU/mL (P=0.011), without a significant change of the plasminogen activator antigen concentration. This was associated with a substantial decrease in plasminogen activator inhibitor-1 activity from 10.4 (8.5 to 16.7) to 6.4 (5.6 to 9.2) IU/mL (P=0.009). Furthermore, plasma levels of prostaglandin E2 and thromboxane B2 markedly decreased (from 9.7 [7.4 to 12.9] to 4.6 [4.3 to 8.1] pg/mL, P=0.0006; and from 106.1 [91.7 to 214.2] to 70.2 [50.3 to 85.6] pg/mL, P=0.002, respectively). During CsA, but not azathioprine, plasma tissue plasminogen activator antigen and plasminogen activator inhibitor-1 levels correlated significantly with prostaglandin E2 (r=0.53, P=0.02; and r=0.60, P=0.008, respectively), and thromboxane B2 (r=0.75, P=0.0001; and r=0.77, P=0.0001, respectively) levels. In conclusion, CsA induced substantial impairment of fibrinolytic activity, which recovered after conversion to azathioprine. The impaired fibrinolysis observed during CsA treatment may be caused by modulation of eicosanoid production or metabolism in vascular endothelial cells and possibly contributes to the high incidence of cardiovascular disease after kidney transplantation.

Effect of mycophenolate mofetil on erythropoiesis in stable renal transplant patients is correlated with mycophenolic acid trough levels (Article)

1999-01-01T00:00:00Z

BACKGROUND: Both mycophenolate mofetil (MMF) and azathioprine (AZA) are immunosuppressive drugs that inhibit purine synthesis. In theory, MMF selectively inhibits lymphocyte proliferation, while AZA has well-known effects on red blood cells and thrombocytes as well. In renal transplant recipients we replaced CsA therapy by MMF in an attempt to reduce the immunosuppressive load 1 year after kidney transplantation. During this study we observed the effect of MMF on haematological parameters such as haemoglobin (Hb), leukocytes, and thrombocytes. METHODS: One year after kidney transplantation 26 stable patients were converted from cyclosporin A (CsA) to MMF (2 g/day). Thereafter, these patients were tapered twice in their MMF dose from 2 g to 1.5 g (4 months after conversion) and from 1.5 to 1 g (8 months after conversion) per day. The Hb levels, leukocyte and thrombocyte counts, and mycophenolic acid (MPA) trough levels were routinely measured. RESULTS: After conversion from CsA to MMF not only creatinine levels and the number of leukocytes, but also the haemoglobin (Hb) level significantly decreased in 21/26 patients (P=0.0004). In eight patients the Hb level dropped more than 1 mmol/l (=1.61 g/dl). Only in two of eight patients was an explanation for blood loss found. The effect on Hb level did not ameliorate after the first MMF dose reduction to 1.5 g/day. After tapering the MMF dose to 1 g/day, the Hb approached the pre-conversion level. Not only the MMF dose but also the mycophenolic acid (MPA) trough level correlated with the Hb level. CONCLUSIONS: After conversion from CsA to MMF 1 year after kidney transplantation, a decrease in Hb level and leukocyte count was observed. The MPA trough level correlated also with the Hb level. The effect on the Hb level was reversible after dose reduction. This finding suggests that MMF exerts a negative effect on erythropoietic cells.

Renal insufficiency after heart transplantation: a case-control study (Article)

1998-01-01T00:00:00Z

BACKGROUND: In Rotterdam 304 heart transplants have been performed since 1984. End-stage renal failure, necessitating renal replacement therapy, has developed in 24 patients (8%) after an interval of 25-121 months (median 79 months). After starting renal replacement therapy one-year survival was only 60%. Overall survival after heart transplantation, however, was favourable: 5 and 10 year survival rates of 79% and 50% respectively. METHODS: A case-control study was performed to identify possible risk factors in cases who went on to develop end-stage renal failure compared to controls. RESULTS: We found that renal failure was not limited to elderly patients with ischaemic heart disease, but also occurred in young patients having dilated cardiomyopathy. A significant rise in the serum creatinine was found in cases compared to controls as early as 3 months after transplantation. Cyclosporin dose and trough levels were not different between cases and controls. Neither were there differences in the use of calcium-antagonists or other antihypertensive drugs, allopurinol or diuretics. Rejection incidence was also similar between the two groups. CONCLUSIONS: Renal failure after heart transplantation is a long term complication of cyclosporin use that is not limited to elderly patients with ischaemic heart disease. Cyclosporin dose and trough levels in the cases were not different from patients maintaining stable good renal function, indicating that cyclosporin nephrotoxicity is the result of an individually determined susceptibility to cyclosporin. Suggestions for future strategies to prevent renal failure are given.

Cytomegalovirus colitis in a CMV-seropositive renal transplant recipient on triple drug therapy (including mycophenolate) (Article)

1997-01-01T00:00:00Z

Stromen langs barrieres (Inaugural Lecture)

1993-10-22T00:00:00Z

Too early for cardiac transplantation-the right decision? (Article)

1992-01-01T00:00:00Z

In 109 out of 479 patients who were referred for cardiac transplantation it was considered to be too early to put them on the waiting list for a donor heart. The clinical course of these 109 patients was analysed in order to verify whether this decision had been right. The mean age of the patients was 43 years, half of them suffered from ischaemic heart disease. The systolic left ventricular function of the patients was severely depressed (mean left ventricular ejection fraction 21%) and the left ventricular cavity was markedly dilated (mean echocardiographic end diastolic dimension 73 mm). Functional capacity, measured by bicycle ergometry, was low: mean maximal workload 62% of the expected load for gender, height and age. The median follow-up duration was 31 months. The survival rate of the patients was better than that of 175 patients who were accepted for transplantation after referral, 92%, 87%, 81%, 71% and 73%, 73%, 71%, 68% after 1, 2, 3 and 4 years respectively. Re-assessment was necessary in 29% of the patients within 1 year and in 52% within 3 years. Twenty patients died: 12 patients died before re-assessment had been initiated (eight sudden deaths), six patients because of progressive heart failure before heart transplantation could be performed and two patients died after heart transplantation. Left ventricular ejection fraction, pulmonary capillary wedge pressure and transpulmonary gradient were not reliable predictors of the course of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment with cyclosporin and risks of graft rejection in male kidney and heart transplant recipients with non-O blood (Article)

1988-01-01T00:00:00Z

In a consecutive series of 146 kidney transplant recipients treated with cyclosporin A a strong correlation between matching for the HLA-A, HLA-B, and HLA-DR loci specificities and outcome of the grafts was observed in male recipients with non-O blood groups. Such a beneficial effect of matching was not found in female patients or male patients with blood group O. In these patients survival of the grafts at one year was good irrespective of the number of HLA-A, B, and DR mismatches. Also in 47 male heart transplant recipients immune responsiveness against mismatched HLA antigens was related to blood group. A significantly higher incidence of rejection episodes was observed in male patients with non-O blood groups (n = 32) than in those with blood group O (n = 15). Matching for HLA-DR reduced the number of acute rejection episodes in male patients with non-O blood. These findings may help explain the controversial reports about the importance of HLA matching in organ transplantation. Furthermore, as most candidates for heart transplantation are male and not of blood group O, the higher incidence of graft rejection in these patients underscores the need for an exchange strategy of donor hearts.

The prophylactic use of Orthoclone OKT3 in kidney and heart transplantation (Article)

1988-01-01T00:00:00Z

Trivalent influenza vaccine in patients on haemodialysis: impaired seroresponse with differences for A-H3N2 and A-H1N1 vaccine components (Article)

1987-03-01T00:00:00Z

One hundred and one patients on haemodialysis, 21 patients on peritoneal dialysis and 30 healthy controls received a trivalent split vaccine containing 15 micrograms haemagglutinin of a recent influenza A-H3N2, influenza A-H1N1 and influenza B strain, respectively. Antibody production after four weeks was determined by the haemagglutination-inhibition test and expressed as response rate, protection rate and overall mean fold increase. The patients on haemodialysis revealed a diminished seroresponse, as compared to patients on peritoneal dialysis and controls. For influenza A-H3N2, this was less distinct than for the other two antigens. In patients on haemodialysis the protection rate was 66% against the A-H3N2 vaccine component (versus 85% in controls, not significant), but only 25% against A-H1N1 and 27% against B (versus 84 and 77% in controls, p less than 0.001). Duration of haemodialysis up to eight years did not affect seroresponse. Patients on haemodialysis who were primed for influenza A-H1N1 in the period 1947-1957, reacted markedly better to the A-H1N1 vaccine component than subjects of other priming periods. A booster injection of the same vaccine dosage four weeks after the first immunization, performed in 98 patients on haemodialysis, was of little value: it had virtually no effect with regard to influenza A-H1N1 and influenza B, and showed, though significantly better, still poor results for A-H3N2. The differences in seroresponse between the A-H3N2 and A-H1N1 vaccine component suggest a major defect of primary, and a minor defect of secondary humoral response in patients on haemodialysis. The consequences for vaccine policy in these patients are discussed.

Value of booster immunisation with influenza vaccine in patients undergoing haemodialysis (Article)

1987-02-01T00:00:00Z

Circadian variation of heart rate but not of blood pressure after heart transplantation (Article)

1987-01-01T00:00:00Z

Results of heart transplantation at Rotterdam, the Netherlands: 1985 to March 1986. (Article)

1986-01-01T00:00:00Z

Interferons, properties and applications (Doctoral Thesis)

1980-05-14T00:00:00Z

The main theme of this thesis is the clinical evaluation of interferon. From the biology of the interferon system and animal experiments it can be expected that exogenous interferon will exert its optimum effect when used to prevent acute infections or to modulate chronic infections. Therefore, we administered interferon to patients with chronic hepatitis B virus infection (chapter 5) and to renal transplant recipients, in whom viral infections occur frequently in the first months after transplantation (chapter 6). The other studies in this thesis are directly related to the problems we met in the clinical studies. We wanted to study interferon in an animal renal transplantation model. For us the most obvious choice was the rat. However, little was known about the production and characterization of rat interferon. Chapter 2 describes our experiences with rat interferon. While we were well underway with the study in renal transplant recipients, we were contacted by Martin Hirsch, who was conducting a similar trial in Boston. Some of his patients receiving 3 x 106 U HLI every other day showed severe bone marrow depression. We had no such problem in our trial, but we used another type of interferon: HFI. For this reason we started a study on the t'oxicity of interferons for bone marrow in vitro.