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    <title>Greef, G.E. de</title>
    <link>http://repub.eur.nl/res/aut/5234/</link>
    <description>List of Publications</description>
    <language>en</language>
    <image>
      <url>http://repub.eur.nl/static-eur/img/logo.png</url>
      <title>RePub, Erasmus University Rotterdam</title>
      <link>http://repub.eur.nl</link>
    </image>
    <item>
      <title>Cytarabine dose for acute myeloid leukemia (Article)</title>
      <link>http://repub.eur.nl/res/pub/25150/</link>
      <pubDate>2011-03-17T00:00:00Z</pubDate>
      <description>BACKGROUND: Cytarabine (ara-C) is an important drug in the treatment of acute myeloid leukemia (AML). High-dose cytarabine (2000 to 3000 mg per square meter of body-surface area) is toxic but results in higher rates of relapse-free survival than does the conventional dose of 100 to 400 mg per square meter. Intermediate dose levels have not been thoroughly evaluated. METHODS: We compared two induction regimens in patients 18 to 60 years of age (median, 49) who had newly diagnosed AML. The intermediate-dose group, totaling 431 patients, received cytarabine at a dose of 200 mg per square meter given by continuous intravenous infusion for 24 hours during cycle 1 of induction therapy and 1000 mg per square meter by infusion for 3 hours twice daily during cycle 2 of induction therapy. The high-dose group, totaling 429 patients, received a dose-escalated regimen of 1000 mg of cytarabine per square meter every 12 hours in cycle 1 and 2000 mg per square meter twice daily in cycle 2. Patients with a complete response did not receive additional cytarabine but received consolidation therapy in a third cycle of chemotherapy (mitoxantrone-etoposide) or underwent autologous or allogeneic stem-cell transplantation. Complete remission rates, survival rates, and toxic effects were assessed for each treatment group. RESULTS: At a median follow-up of 5 years, no significant differences were noted between the intermediate-dose group and the high-dose group with respect to complete remission rates (80% and 82%, respectively), probability of relapse, event-free survival at 5 years (34% and 35%), or overall survival (40% and 42%). High-dose cytarabine provided no clear advantage in any prognostic subgroup. The high-dose treatment resulted in higher incidences of grade 3 and grade 4 toxic effects (in cycle 1), prolonged hospitalization, and delayed neutrophil recovery (in cycle 2) and platelet recovery (in cycles 2 and 3). CONCLUSIONS: Induction therapy with cytarabine at the lower dose already produced maximal antileukemic effects for all response end points, suggesting a plateau in the dose-response relationship above this dose level. High-dose cytarabine results in excessive toxic effects without therapeutic benefit. (Netherlands Trial Register number, NTR230.). Copyright </description>
    </item> <item>
      <title>Clinical effectiveness of leucoreduced, pooled donor platelet concentrates, stored in plasma or additive solution with and without pathogen reduction (Article)</title>
      <link>http://repub.eur.nl/res/pub/20660/</link>
      <pubDate>2010-07-01T00:00:00Z</pubDate>
      <description>Pathogen reduction (PR) of platelet products increases costs and available clinical studies are equivocal with respect to clinical and haemostatic effectiveness. We conducted a multicentre, open-label, randomized, non-inferiority trial comparing the clinical effectiveness of buffy-coat derived leucoreduced platelet concentrates (PC) stored for up to 7 d in plasma with platelets stored in platelet additive solution III (PASIII) without and with treatment with amotosalen-HCl/ultraviolet-A (UVA) photochemical pathogen reduction (PR-PASIII). Primary endpoint of the study was 1-h corrected count increment (CCI). Secondary endpoints were 24-h CCI, bleeding, transfusion requirement of red cells and PC, platelet transfusion interval and adverse transfusion reactions. Compared to plasma-PC, in the intention to treat analysis of 278 evaluable patients the mean difference for the 1-h CCI of PR-PASIII-PC and PASIII-PC was -31% (P &lt; 0·0001) and -9% (P = n.s.), respectively. Twenty-seven patients (32%) had bleeding events in the PR-PASIII arm, as compared to 19 (19%) in the plasma arm and 14 (15%) in the PASIII arm (P = 0·034). Despite the potential advantages of pathogen (and leucocyte) inactivation of amotosalen-HCl/UVA-treated platelet products, their clinical efficacy is inferior to platelets stored in plasma, warranting a critical reappraisal of employing this technique for clinical use.</description>
    </item> <item>
      <title>Low frequency of MLL-partial tandem duplications in paediatric acute myeloid leukaemia using MLPA as a novel DNA screenings technique (Article)</title>
      <link>http://repub.eur.nl/res/pub/28223/</link>
      <pubDate>2010-07-01T00:00:00Z</pubDate>
      <description>Mixed-lineage leukaemia (MLL)-partial tandem duplications (PTDs) are found in 3-5% of adult acute myeloid leukaemia (AML), and are associated with poor prognosis. In adult AML, MLL-PTD is only detected in patients with trisomy 11 or internal tandem duplications of FLT3 (FLT3-ITD). To date, studies in paediatric AML are scarce, and reported large differences in the frequency of MLL-PTD, frequently utilising mRNA RT-PCR only to detect MLL-PTDs. We studied the frequency of MLL-PTD in a large cohort of paediatric AML (n = 276) and the results from two different methods, i.e. mRNA RT-PCR, and multiplex ligation-dependent probe amplification (MLPA), a method designed to detect copy number differences of specific DNA sequences. In some patients with an MLL-rearrangement, MLL-PTD transcripts were detected, but were not confirmed by DNA-MLPA, indicating that DNA-MLPA can more accurately detect MLL-PTD compared to mRNA RT-PCR. In paediatric AML, MLL-PTD was detected in 7/276 patients (2.5%). One case had a trisomy 11, while the others had normal cytogenetics. Furthermore 4 of the 7 patients revealed a FLT3-ITD, which was significantly higher compared with the other AML cases (p = 0.016). In conclusion, using DNA-MLPA as a novel screenings technique in combination with mRNA RT-PCR a low frequency of MLL-PTD in paediatric AML was found. Larger prospective studies are needed to further define the prognostic relevance of MLL-PTD in paediatric AML. </description>
    </item> <item>
      <title>Monosomal karyotype in acute myeloid leukemia: A better indicator of poor prognosis than a complex karyotype (Article)</title>
      <link>http://repub.eur.nl/res/pub/14492/</link>
      <pubDate>2008-10-10T00:00:00Z</pubDate>
      <description>Purpose: To investigate the prognostic value of various cytogenetic components of a complex karyotype in acute myeloid leukemia (AML). Patients and Methods: Cytogenetics and overall survival (OS) were analyzed in 1,975 AML patients age 15 to 60 years. Results: Besides AML with normal cytogenetics (CN) and core binding factor (CBF) abnormalities, we distinguished 733 patients with cytogenetic abnormalities. Among the latter subgroup, loss of a single chromosome (n = 109) conferred negative prognostic impact (4-year OS, 12%; poor outcome). Loss of chromosome 7 was most common, but outcome of AML patients with single monosomy -7 (n = 63; 4-year OS, 13%) and other single autosomal monosomies (n = 46; 4-year OS, 12%) did not differ. Structural chromosomal abnormalities influenced prognosis only in association with a single autosomal monosomy (4-year OS, 4% for very poor v 24% for poor). We derived a monosomal karyotype (MK) as a predictor for very poor prognosis of AML that refers to two or more distinct autosomal chromosome monosomies (n = 116; 4-year OS, 3%) or one single autosomal monosomy in the presence of structural abnormalities (n = 68; 4-year OS, 4%). In direct comparisons, MK provides significantly better prognostic prediction than the traditionally defined complex karyotype, which considers any three or more or five or more clonal cytogenetic abnormalities, and also than various individual specific cytogenetic abnormalities (eg, del[5q], inv[3]/t[3;3]) associated with very poor outcome. Conclusion: MK enables (in addition to CN and CBF) the prognostic classification of two new aggregates of cytogenetically abnormal AML, the unfavorable risk MK-negative category (4-year OS, 26% ± 2%) and the highly unfavorable risk MK-positive category (4-year OS, 4% ± 1%).</description>
    </item> <item>
      <title>Kinetic analysis reveals potency of CD4+ CD25bright+ regulatory T-cells in kidney transplant patients (Article)</title>
      <link>http://repub.eur.nl/res/pub/36372/</link>
      <pubDate>2007-11-01T00:00:00Z</pubDate>
      <description>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. </description>
    </item> <item>
      <title>Transfusion of pooled buffy coat platelet components prepared with photochemical pathogen inactivation treatment: the euroSPRITE trial (Article)</title>
      <link>http://repub.eur.nl/res/pub/8233/</link>
      <pubDate>2003-03-15T00:00:00Z</pubDate>
      <description>A nucleic acid-targeted photochemical treatment (PCT) using amotosalen HCl (S-59) and ultraviolet A (UVA) light was developed to inactivate viruses, bacteria, protozoa, and leukocytes in platelet components. We conducted a controlled, randomized, double-blinded trial in thrombocytopenic patients requiring repeated platelet transfusions for up to 56 days of support to evaluate the therapeutic efficacy and safety of platelet components prepared with the buffy coat method using this pathogen inactivation process. A total of 103 patients received one or more transfusions of either PCT test (311 transfusions) or conventional reference (256 transfusions) pooled, leukoreduced platelet components stored for up to 5 days before transfusion. More than 50% of the PCT platelet components were stored for 4 to 5 days prior to transfusion. The mean 1-hour corrected count increment for up to the first 8 test and reference transfusions was not statistically significantly different between treatment groups (13,100 +/- 5400 vs 14,900 +/- 6200, P =.11). By longitudinal regression analysis for all transfusions, equal doses of test and reference components did not differ significantly with respect to the 1-hour (95% confidence interval [CI], -3.1 to 6.1 x 10(9)/L, P =.53) and 24-hour (95% CI, -1.3 to 6.5 x 10(9)/L, P =.19) posttransfusion platelet count. Platelet transfusion dose, pretransfusion storage duration, and patient size were significant covariates (P &lt;.001) for posttransfusion platelet counts. Clinical hemostasis, hemorrhagic adverse events, and overall adverse events were not different between the treatment groups. Platelet components prepared with PCT offer the potential to further improve the safety of platelet transfusion using technology compatible with current methods to prepare buffy coat platelet components.</description>
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      <title>High EVI1 expression predicts poor survival in acute myeloid leukemia: a study of 319 de novo AML patients (Article)</title>
      <link>http://repub.eur.nl/res/pub/8228/</link>
      <pubDate>2003-01-01T00:00:00Z</pubDate>
      <description>The proto-oncogene EVI1 encodes a DNA binding protein and is located on
      chromosome 3q26. The gene is aberrantly expressed in acute myeloid
      leukemia (AML) patients carrying 3q26 abnormalities. Two mRNAs are
      transcribed from this locus: EVI1 and a fusion of EVI1 with MDS1
      (MDS1-EVI1), a gene located 5' of EVI1. The purpose of this study was to
      investigate which of the 2 gene products is involved in transformation in
      human AML. To discriminate between EVI1 and MDS1-EVI1 transcripts,
      distinct real-time quantitative polymerase chain reaction (PCR) assays
      were developed. Patients with 3q26 abnormalities often showed high EVI1
      and MDS1-EVI1 expression. In a cohort of 319 AML patients, 4 subgroups
      could be distinguished: EVI1(+) and MDS1-EVI1(-) (6 patients; group I),
      EVI1(+) and MDS1-EVI1(+) (26 patients; group II), EVI1(-) and MDS1-EVI1(+)
      (12 patients; group III), and EVI1(-) and MDS1-EVI1(-) (275 patients;
      group IV). The only 4 patients with a 3q26 aberration belonged to groups I
      and II. Interestingly, high EVI1 and not MDS1-EVI1 expression was
      associated with unfavorable karyotypes (eg, -7/7q-) or complex karyotypes.
      Moreover, a significant correlation was observed between EVI1 expression
      and 11q23 aberrations (mixed lineage leukemia [MLL] gene involvement).
      Patients from groups I and II had significantly shorter overall and
      event-free survival than patients in groups III and IV. Our data
      demonstrate that high EVI1 expression is an independent poor prognostic
      marker within the intermediate- risk karyotypic group.</description>
    </item> <item>
      <title>Effect of priming with granulocyte colony-stimulating factor on the outcome of chemotherapy for acute myeloid leukemia (Article)</title>
      <link>http://repub.eur.nl/res/pub/8458/</link>
      <pubDate>2003-01-01T00:00:00Z</pubDate>
      <description>BACKGROUND: Sensitization of leukemic cells with hematopoietic growth
      factors may enhance the cytotoxicity of chemotherapy in acute myeloid
      leukemia (AML). METHODS: In a multicenter randomized trial, we assigned
      patients (age range, 18 to 60 years) with newly diagnosed AML to receive
      cytarabine plus idarubicin (cycle 1) and cytarabine plus amsacrin (cycle
      2) with granulocyte colony-stimulating factor (G-CSF) (321 patients) or
      without G-CSF (319). G-CSF was given concurrently with chemotherapy only.
      Idarubicin and amsacrin were given at the end of a cycle to allow the
      cell-cycle-dependent cytotoxicity of cytarabine in the context of G-CSF to
      have a greater effect. The effect of G-CSF on disease-free survival was
      assessed in all patients and in cytogenetically distinct prognostic
      subgroups. RESULTS: After induction chemotherapy, the rates of response
      were not significantly different in the two groups. After a median
      follow-up of 55 months, patients in complete remission after induction
      chemotherapy plus G-CSF had a higher rate of disease-free survival than
      patients who did not receive G-CSF (42 percent vs. 33 percent at four
      years, P=0.02), owing to a reduced probability of relapse (relative risk,
      0.77; 95 percent confidence interval, 0.61 to 0.99; P=0.04). G-CSF did not
      significantly improve overall survival (P=0.16). Although G-CSF did not
      improve the outcome in the subgroup with an unfavorable prognosis, the 72
      percent of patients with standard-risk AML benefited from G-CSF therapy
      (overall survival at four years, 45 percent, as compared with 35 percent
      in the group that did not receive G-CSF [relative risk of death, 0.75; 95
      percent confidence interval, 0.59 to 0.95; P=0.02]; disease-free survival,
      45 percent vs. 33 percent [relative risk, 0.70]; 95 percent confidence
      interval, 0.55 to 0.90; P=0.006). CONCLUSIONS: Sensitization of leukemic
      cells with growth factors is a clinically applicable means of enhancing
      the efficacy of chemotherapy in patients with AML.</description>
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      <title>Complete remission of t(11;17) positive acute promyelocytic leukemia induced by all-trans retinoic acid and granulocyte colony-stimulating factor (Article)</title>
      <link>http://repub.eur.nl/res/pub/9124/</link>
      <pubDate>1999-01-01T00:00:00Z</pubDate>
      <description>The combined use of retinoic acid and chemotherapy has led to an important
          improvement of cure rates in acute promyelocytic leukemia. Retinoic acid
          forces terminal maturation of the malignant cells and this application
          represents the first generally accepted differentiation-based therapy in
          leukemia. Unfortunately, similar approaches have failed in other types of
          hematological malignancies suggesting that the applicability is limited to
          this specific subgroup of patients. This has been endorsed by the
          notorious lack of response in acute promyelocytic leukemia bearing the
          variant t(11;17) translocation. Based on the reported synergistic effects
          of retinoic acid and the hematopoietic growth factor granulocyte
          colony-stimulating factor (G-CSF), we studied maturation of t(11;17)
          positive leukemia cells using several combinations of retinoic acid and
          growth factors. In cultures with retinoic acid or G-CSF the leukemic cells
          did not differentiate into mature granulocytes, but striking granulocytic
          differentiation occurred with the combination of both agents. At relapse,
          the patient was treated with retinoic acid and G-CSF before reinduction
          chemotherapy. With retinoic acid and G-CSF treatment alone, complete
          granulocytic maturation of the leukemic cells occurred in vivo, followed
          by a complete cytogenetical and hematological remission. Bone marrow and
          blood became negative in fluorescense in situ hybridization analysis and
          semi-quantitative polymerase chain reaction showed a profound reduction of
          promyelocytic leukemia zinc finger-retinoic acid receptor-alpha fusion
          transcripts. This shows that t(11;17) positive leukemia cells are not
          intrinsically resistant to retinoic acid, provided that the proper
          costimulus is administered. These observations may encourage the
          investigation of combinations of all-trans retinoic acid and hematopoietic
          growth factors in other types of leukemia.</description>
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