Roodnat, J.I.

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.

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

KIR-ligand mismatches are associated with reduced long-term graft survival in HLA-compatible kidney transplantation (Article)

2011-09-01T00:00:00Z

Natural killer (NK) cells are cytotoxic lymphocytes of the innate immune system with the ability to detect HLA class I disparities via killer-cell immunoglobulin-like receptors (KIR). To test whether such KIR-ligand mismatches contribute to the rejection of human solid allografts, we did a retrospective cohort study of 397 HLA-DR-compatible kidney transplantations and determined the KIR and HLA genotypes of recipients and the HLA genotypes of donors. In transplantations compatible for HLA-A, HLA-B and HLA-DR (n = 137), in which a role for T cells and HLA antibodies in rejection was minimized, KIR-ligand mismatches were associated with an approximately 25% reduction in 10-year death-censored graft survival (p = 0.043). This effect was comparable to the effect of classical HLA-A and HLA-B incompatibility, and in HLA-A,-B- incompatible transplantations (n = 260) no significant additional effect of KIR-ligand mismatches was observed. Multivariate Cox regression analysis confirmed the effect of KIR-ligand mismatching as an independent risk factor in HLA-A,-B,-DR-compatible transplantations (hazard ratio 2.29, range 1.03-5.10, p = 0.043). This finding constitutes the first indication that alloreactive NK cells may thwart the success of HLA-compatible kidney transplantations, and suggests that suppression of NK-cell activity can improve the survival of such kidney grafts. In this retrospective study, KIR and HLA typing reveals that in kidney transplantations compatible for HLA-A, B and DR, the presence of KIR-ligand mismatches is associated with a significant reduction in 10-year death-censored graft survival. See editorial by Rajalingam and Gebel on page 1771.

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

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.

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.

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.

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.

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.

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

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.

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.

Resolution of IgM Nephropathy After Rituximab Treatment (Article)

2009-06-01T00:00:00Z

Immunoglobulin M (IgM) nephropathy is an idiopathic glomerulonephritis characterized by mesangial deposits of IgM. IgM nephropathy presenting with proteinuria, especially nephrotic syndrome, frequently is steroid dependent or steroid resistant and associated with reaching end-stage renal disease after a 15-year follow-up. Because no long-term effective treatment is known for patients with IgM nephropathy, there is a clear need for therapeutic alternatives. We describe a patient who reached end-stage renal disease 20 years after IgM nephropathy was diagnosed at the age of 3 years. IgM nephropathy recurred after kidney transplantation, leading to microscopic hematuria and proteinuria. High-dose steroid therapy was not effective, and kidney function slowly decreased. Three years after transplantation, 2 doses of rituximab were administered, leading to complete remission of the IgM nephropathy. One year after rituximab treatment, the patient has stable kidney function, normal urinary sediment, and no proteinuria. Rituximab may be a valuable novel therapeutic drug for the treatment of patients with IgM nephropathy.

Quiz page. Muckle Wells syndrome. (Article)

2008-11-01T00:00:00Z

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.

Multivariable analysis of risk factors in renal transplantation (Doctoral Thesis)

2002-11-13T00:00:00Z

The aim of this thesis is to make a distinction between potentially important variables in their influence on the risk of failure after renal transplantation. Which of the known variables really influence our results? Which variables can be neglected? Most studies on this subject are univariable analysis. In these studies selection and inter-dependency of the influence of variables cannot be taken into account. Besides, the importance of the influence of different variables is studied in different analyses and cannot be compared. Multivariable analysis with the Cox proportional hazards analysis offers best prospects to compare the influences of different variables on the failure risk. In the next chapter we describe how the Cox deals with our question and how risk factors are defined. Our principal motivation was to come to an understanding of the reasons for failure after renal transplantation. With this knowledge we could try to decrease the prevalence of high risk or combination of high risk factors in recipients

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.