Teun van Gelder

Erasmus MC, Rotterdam, South Holland, Netherlands

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Publications (297)1143.63 Total impact

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    ABSTRACT: Biologic drugs ('biologics'), have revolutionized the treatment of patients with extensive and therapy-resistant psoriasis. Unfortunately, biologics (the anti-TNFα agents adalimumab, infliximab and etanercept, and the anti-p40(IL12/23) ustekinumab) appear to lose efficacy over time and many patients are eventually switched to another biologic This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    British Journal of Dermatology 12/2014; · 3.76 Impact Factor
  • 10/2014; 15(11):e470–e471.
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    ABSTRACT: Intra-patient variability (IPV) in tacrolimus exposure is associated with renal allograft failure. The aim of this study was to investigate whether conversion from the twice-daily tacrolimus formulation (Tac-TD) to a once-daily formulation (Tac-OD) leads to a lower IPV in tacrolimus exposure.
    Therapeutic drug monitoring. 09/2014;
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    ABSTRACT: The transplantation literature includes numerous papers that report associations between polymorphisms in genes encoding metabolizing enzymes and drug transporters, and pharmacokinetic data on immunosuppressive drugs. Most of these studies are retrospective in design, and although a substantial number report significant associations, pharmacogenetic tests are hardly used in clinical practice. One of the reasons for this poor implementation is the current lack of evidence of improved clinical outcome with pharmacogenetic testing. Furthermore, with efficient therapeutic drug monitoring it is possible to rapidly correct for the effect of genotypic deviations on pharmacokinetics, thereby decreasing the utility of genotype-based dosing. The future of pharmacogenetics will be in treatment models in which patient characteristics are combined with data on polymorphisms in multiple genes. These models should focus on pharmacodynamic parameters, variations in the expression of drug transporter proteins, and predictors of toxicity. Such models will provide more information than the relatively small candidate gene studies performed so far. For implementation of these models into clinical practice, linkage of genotype data to medication prescription systems within electronic health records will be crucial.
    Nature Reviews Nephrology 09/2014; · 7.94 Impact Factor
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    ABSTRACT: This overview describes the full spectrum of current pre-clinical and clinical kidney-, liver-, heart- and lung transplantation research performed in Erasmus MC – University Medical Centre in Rotterdam, The Netherlands. An update is provided on the development of a large living donor kidney transplantation program and on optimization of kidney allocation, including the implementation of a domino kidney-donation program. Our current research efforts to optimize immunosuppressive regiments and find novel targets for immunosuppressive therapy, our recent studies on prevention of ischemia-reperfusion-induced graft injury, our newest findings on stimulation of tissue regeneration, our novel approaches to prevent rejection and viral infection, and our latest insights in the regulation of allograft rejection, are summarized.
    Transplant Immunology 09/2014; · 1.52 Impact Factor
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    ABSTRACT: Chronic kidney disease (CKD) after liver transplantation (LT) is a major clinical problem that appears to be associated with nongenetic as well as genetic determinants. Calcineurin inhibitor (CNI) use is considered to play a major role in the development of CKD after LT. We studied the influence of single-nucleotide polymorphisms (SNPs) in the genes of the donor and recipient CNI-metabolizing enzyme CYP3A5 and the CNI-transporting ABCB1 on the development of CKD after LT.
    Pharmacogenetics and Genomics 07/2014; · 3.61 Impact Factor
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    ABSTRACT: Several lines of evidence suggest a T cell-mediated immune response in paraneoplastic neurological syndromes with anti-Hu antibodies (Hu-PNS). In order to investigate whether suppression of T cell-mediated immune responses in Hu-PNS patients improved their neurological outcome, we performed a prospective open-label, single-arm study on sirolimus.
    Neuro-oncology. 07/2014;
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    ABSTRACT: In the past decade, many tyrosine-kinase inhibitors have been introduced in oncology and haemato-oncology. Because this new class of drugs is extensively used, serious drug-drug interactions are an increasing risk. In this Review, we give a comprehensive overview of known or suspected drug-drug interactions between tyrosine-kinase inhibitors and other drugs. We discuss all haemato-oncological and oncological tyrosine-kinase inhibitors that had been approved by Aug 1, 2013, by the US Food and Drug Administration or the European Medicines Agency. Various clinically relevant drug interactions with tyrosine-kinase inhibitors have been identified. Most interactions concern altered bioavailability due to altered stomach pH, metabolism by cytochrome P450 isoenzymes, and prolongation of the QTc interval. To guarantee the safe use of tyrosine-kinase inhibitors, a drugs review for each patient is needed. This Review provides specific recommendations to guide haemato-oncologists, oncologists, and clinical pharmacists, through the process of managing drug-drug interactions during treatment with tyrosine-kinase inhibitors in daily clinical practice.
    The Lancet Oncology 07/2014; 15(8):e315-e326. · 25.12 Impact Factor
  • Teun van Gelder
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    ABSTRACT: Within-patient variability in immunosuppressive drug exposure is easily identified by measurement of drug concentrations at the outpatient clinic. Fluctuating levels despite a stable drug dose can be observed in a substantial proportion of patients. It has now been shown that this within-patient variability is a predictor for poor long-term outcome after transplantation. Nonadherence most likely is an important determinant of variability, and strategies to tackle nonadherence are being developed.
    Kidney international. 06/2014; 85(6):1267-8.
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    ABSTRACT: Hypertension is a common side effect of calcineurin inhibitors (CNIs), which are drugs used to prevent rejection after transplantation. Hypertension after kidney transplantation has been associated with earlier graft failure and higher cardiovascular mortality in the recipient. Recent data indicate that enzymes and transporters involved in CNI pharmacokinetics and pharmacodynamics, including CYP3A5, ABCB1, WNK4 and SPAK, are also associated with salt-sensitive hypertension. These insights raise the question whether polymorphisms in the genes encoding these proteins increase the risk of CNI-induced hypertension. Predicting who is at risk for CNI-induced hypertension may be useful for when selecting specific interventions, including dietary salt restriction, thiazide diuretics or a CNI-free immunosuppressive regimen. This review aims to explore the pharmacogenetics of CNI-induced hypertension, highlighting the knowns and unknowns.
    Pharmacogenomics 06/2014; 15(9):1243-51. · 3.86 Impact Factor
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    ABSTRACT: Mycophenolate mofetil (MMF) is used to prevent acute rejection following solid organ transplantation in transplant centers all over the world. Patients from different ethnic backgrounds are treated with this drug, for which therapeutic drug monitoring (TDM) has not become the standard of practice in most centers. Whether or not some ethnic groups require a different MMF dose has been a topic of debate in recent years.In this review it is shown that Asian patients, compared to Caucasian patients, with a comparable MMF dose reach higher mycophenolic acid (MPA) exposure. Also clinical experience points towards more adverse events in case of treatment with 1 gram MMF bid in Asian patients, and therefore for this ethnic group a lower maintenance dose seems justified. In contrast, African American patients reach similar drug concentrations as Caucasians patients receiving the same MMF dose but due to immunological reasons they require a higher MMF dose to reach comparable acute rejection incidences.When TDM is performed clinicians can correct the dose and compensate for inter-ethnic differences in drug exposure. Otherwise, it is important to choose the right dose. This optimal dose is 20%-46% lower in Asian transplant recipients than in Caucasian or African American patients.This article is protected by copyright. All rights reserved.
    Transplant International 06/2014; · 3.16 Impact Factor
  • Teun van Gelder, Jo H M Berden, Stefan P Berger
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    ABSTRACT: Mycophenolic acid (MPA) has become the cornerstone in the treatment of lupus nephritis. However, response rates are still far from ideal in clinical trials. Uncertainty exists regarding the correct dosing of MPA, and the recommended doses vary between recently published guidelines. Side effects are an additional problem resulting in frequent dose reduction and possible suboptimal exposure.In this review, we discuss the large variability between patients in drug exposure to MPA and the evidence for a relationship between drug exposure and efficacy in lupus nephritis. Methods for drug monitoring of MPA are discussed, and based on the current literature, we suggest as potential target levels a pre-dose level of 3.0 mg/L and an area under the concentration-versus-time curve between 35 and 45 mg h/L.Therapeutic drug monitoring may improve response rates in lupus nephritis by preventing low exposure and at the same time may reduce unnecessary side effects in patients who have high drug exposure with standard dose MPA. We specifically advise assessment of MPA drug exposure early after start of treatment and before concluding that treatment with MPA has failed.
    Nephrology Dialysis Transplantation 05/2014; · 3.37 Impact Factor
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    ABSTRACT: Acute rejection (AR) remains a concern for kidney transplantation. Cytokines are key mediators in the induction and effector phases of all immune and inflammatory responses. Single-nucleotide-polymorphisms (SNPs) in cytokines and their receptors may relate to AR. We investigated the relation between AR and SNPs in the genes encoding for IL-2(-330G>T), IL-10(-592C>A and -1082G>A), TGF-β1(915G>C), and IL-2RB(rs228942 C>A and rs228953 C>T) in 325 renal transplant patients during the first year after transplantation. The overall incidence of AR was 15.4%. In multivariate analysis, only the use of induction therapy was correlated with AR (odds ratio 1.9; 95%-confidence interval 1.1 - 3.7; p = 0.04). No statistically significant associations between the SNPs studied and AR were observed. SNPs in the investigated cytokines and their receptors were not associated with the risk of AR. Genotyping patients for these SNPs is unlikely to aid the clinician in adjusting the immunosuppressive therapy for individual patients. This article is protected by copyright. All rights reserved.
    Clinical Transplantation 03/2014; · 1.63 Impact Factor
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    ABSTRACT: Calcineurin inhibitors (CNIs) are essential immunosuppressive drugs after renal transplantation. Because of nephrotoxicity, withdrawal has been a challenge since their introduction. A randomized multicenter trial included 212 kidney patients transplanted between 1997 and 1999. All patients were initially treated with mycophenolate mofetil (MMF), cyclosporine A (CsA), and prednisone (pred). At 6 months after transplantation, 63 patients were randomized for MMF/pred, 76 for MMF/CsA, and 73 for MMF/CsA/pred. Within 18 months after randomization 23 patients experienced a rejection episode: MMF/pred (27.0%), MMF/CsA (6.8%) and MMF/CsA/pred (1.4%) (P<0.001). During 15 years of follow-up, 73 patients died with a functioning graft, and 43 patients lost their graft. Ninety-six were alive with a functioning graft. Intention-to-treat analysis did not show a significant difference in patient and graft survival. In multivariate analysis, death-censored graft survival was significantly associated with serum creatinine at 6 months after transplantation and maximum PRA but not with the randomization group. CNI withdrawal did not result in a reduced incidence of or death by malignancy or cardiovascular disease. Death-censored graft survival was significantly worse in those patients randomized for CNI withdrawal that had to be reverted to CNI. Independent of randomization group, compared with no rejection, death-censored graft survival was significantly worse in 23 patients with acute rejection after randomization. Fifteen years after conversion to a CNI free regimen, there was no benefit regarding graft and patient survival or regarding prevalence of or death by comorbidities. However, rejection shortly after CNI withdrawal was associated with decreased graft survival.
    Transplantation 02/2014; · 3.78 Impact Factor
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    American Journal of Transplantation 02/2014; · 6.19 Impact Factor
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    ABSTRACT: Background. Nonadherence to medication is a common problem after kidney transplantation. The aim of this study was to explore attitudes towards medication, adherence, and the relationship with clinical outcomes. Method. Kidney recipients participated in a Q-methodological study 6 weeks after transplantation. As a measure of medication adherence, respondents completed the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS©-interview). Moreover, the intrapatient variability in the pharmacokinetics of tacrolimus was calculated, which measures stability of drug intake. Data on graft survival was retrieved from patient records up to 2 years after transplantation. Results. 113 renal transplant recipients (19–75 years old) participated in the study. Results revealed three attitudes towards medication adherence—attitude 1: “confident and accurate,” attitude 2: “concerned and vigilant,” and attitude 3: “appearance oriented and assertive.” We found association of attitudes with intrapatient variability in pharmacokinetics of tacrolimus, but not with self-reported nonadherence or graft survival. However, self-reported nonadherence immediately after transplantation was associated with lower two-year graft survival. Conclusion. These preliminary findings suggest that nonadherence shortly after kidney transplantation may be a risk factor for lower graft survival in the years to follow. The attitudes to medication were not a risk factor.
    Journal of Transplantation 01/2014;
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    ABSTRACT: Mycophenolic acid (MPA) has a low therapeutic index and large inter-individual pharmacokinetic variability necessitating therapeutic drug monitoring to individualise dosing after transplantation. There is an ongoing discrepancy as to whether plasma MPA concentrations sufficiently predict kidney rejection or toxicity and whether immunosuppressant concentrations within the graft tissue may better predict transplant outcomes. The aim of the study was to develop an LC-MS/MS method for the quantification of MPA concentrations in human kidney biopsies taken as part of routine clinical procedures. A total of 4 surplus human kidney biopsies obtained from 4 different kidney transplant recipients were available to use for this study. MPA was also quantified in 2 kidney samples from rats administered MPA to assess tissue extraction reproducibility. Human kidney biopsies and rat kidneys were homogenised mechanically and underwent liquid-liquid extraction before analysis by LC-MS/MS. MPA-free human kidney tissue was used in calibrators and quality control samples. Analyte detection was achieved from multiple reaction monitoring of the ammonium adducts of both MPA (m/z 321.1→207.3) and N-phthaloyl-l-phenylalanine (PPA, internal standard, m/z 296.2→250.2) using positive electrospray ionisation. The method was linear (calibration curves R(2)>0.99, n=10), precise, and accurate with coefficients of variation and bias less than 15%. Extraction efficiencies for MPA and PPA were approximately 97% and 86%, respectively, and matrix effects were minimal. In 4 kidney transplant recipients, tissue MPA concentrations ranged from 1.3 to 7.7ng/mg of tissue, however, the correlation between blood (C0) and tissue MPA concentrations could not be established. The method was successfully applied to the quantification of MPA in human kidney biopsies without the need to alter current clinical protocols.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 12/2013; 945-946C:171-177. · 2.78 Impact Factor
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    ABSTRACT: The calcineurin inhibitor tacrolimus is the backbone of immunosuppressive drug therapy after solid organ transplantation. Tacrolimus is effective in preventing acute rejection but has considerable toxicity and displays marked inter-individual variability in its pharmacokinetics and pharmacodynamics. The genetic basis of these phenomena is reviewed here. With regard to its pharmacokinetic variability, a single nucleotide polymorphism (SNP) in cytochrome P450 (CYP) 3A5 (6986A>G) has been consistently associated with tacrolimus dose requirement. Patients expressing CYP3A5 (those carrying the A nucleotide, defined as the *1 allele) have a dose requirement that is around 50 % higher than non-expressers (those homozygous for the G nucleotide, defined as the *3 allele). A randomised controlled study in kidney transplant recipients has demonstrated that a CYP3A5 genotype-based approach to tacrolimus dosing leads to more patients reaching the target concentration early after transplantation. However, no improvement of clinical outcomes (rejection incidence, toxicity) was observed, which may have been the result of the design of this particular study. In addition to CYP3A5 genotype, other genetic variants may also contribute to the variability in tacrolimus pharmacokinetics. Among these, the CYP3A4*22 and POR*28 SNPs are the most promising. Individuals carrying the CYP3A4*22 T-variant allele have a lower tacrolimus dose requirement than individuals with the CYP3A4*22 CC genotype and this effect appears to be independent of CYP3A5 genotype status. Individuals carrying the POR*28 T-variant allele have a higher tacrolimus dose requirement than POR*28 CC homozygotes but this association was only found in CYP3A5-expressing individuals. Other, less well-defined SNPs have been inconsistently associated with tacrolimus dose requirement. It is envisaged that in the future, algorithms incorporating clinical, demographic and genetic variables will be developed that will aid clinicians with the determination of the tacrolimus starting dose for an individual transplant recipient. Such an approach may limit early tacrolimus under-exposure and toxicity. With regard to tacrolimus pharmacodynamics, no strong genotype-phenotype relationships have been identified. Certain SNPs associate with rejection risk but these observations await replication. Likewise, the genetic basis of tacrolimus-induced toxicity remains unclarified. SNPs in the genes encoding for the drug transporter ABCB1 and the CYP3A enzymes may relate to chronic nephrotoxicity but findings have been inconsistent. No genetic markers reliably predict new-onset diabetes mellitus after transplantation, hypertension or neurotoxicity. The CYP3A5*1 SNP is currently the most promising biomarker for tailoring tacrolimus treatment. However, before CYP3A5 genotyping is incorporated into the routine clinical care of transplant recipients, prospective clinical trials are needed to determine whether such a strategy improves patient outcomes. The role of pharmacogenetics in tacrolimus pharmacodynamics should be explored further by the study of intra-lymphocyte and tissue tacrolimus concentrations.
    Clinical Pharmacokinetics 11/2013; · 5.49 Impact Factor
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    ABSTRACT: Pharmacogenetics has generated many expectations for its potential to proactively individualize therapy and improve medical care. However, despite the huge amount of reported genetic associations with either pharmacokinetics or pharmacodynamics of drugs, the translation into patient care is still slow. In fact, strong evidence for a substantial clinical benefit of pharmacogenetic testing is still limited, with a few exceptions. In kidney transplantation, established pharmacogenetic discoveries are being investigated for application in the clinic to improve efficacy and to limit toxicity associated with the use of immunosuppressive drugs, especially the frequently used calcineurin inhibitors (CNIs) tacrolimus and ciclosporin. The purpose of the present review is to picture the current status of CNI pharmacogenetics and to discuss the most promising leads that have been followed so far.
    British Journal of Clinical Pharmacology 10/2013; · 3.69 Impact Factor
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    ABSTRACT: New-onset diabetes after transplantation (NODAT) is an important complication after kidney transplantation. The etiology of the malady is multifactorial and includes both environmental and genetic factors. NODAT is a polygenic disease and many single-nucleotide polymorphisms could constitute potential risk factors. Peroxisome proliferator-activated receptor α (PPARα) and P450 oxidoreductase (POR) play a central role in the control of energy metabolism in humans. Some recent data highlighted a possible functional impact of two single-nucleotide polymorphisms in PPARα (rs4253728 G>A and rs4823613 A>G) and one coding variant in POR (rs1057868; POR*28; A503V) on the activity of their respective encoded proteins. In the present study, we assessed the association between these variants and the risk of developing NODAT after kidney transplantation. Development of NODAT was investigated in 101 renal transplant recipients receiving tacrolimus-based immunosuppressive therapy. Patients were genotyped for PPARα and POR. The incidence of NODAT was compared between different genotypes. Kaplan-Meier and Cox's proportional-hazard analysis were used to evaluate the association of NODAT with potential risk factors. Potential nongenetic risk factors were also considered. The PPARα rs4253728A>G and POR*28 variant alleles were both independently associated with an increased risk for NODAT with respective odds ratios of 8.6 [95% confidence interval (CI) [1.4, 54.2]; P=0.02] and 8.1 (95% CI [1.1, 58.3]; P=0.04). Other risk predictors included sex and body weight. This candidate-gene study shows that polymorphisms in PPARα and POR might predispose patients being treated with tacrolimus to the development of NODAT after kidney transplantation. Patient management after organ transplantation might benefit from genotype data.
    Pharmacogenetics and Genomics 10/2013; · 3.61 Impact Factor

Publication Stats

5k Citations
1,143.63 Total Impact Points

Institutions

  • 2002–2014
    • Erasmus MC
      • • Department of Internal Medicine
      • • Department of Clinical Chemistry (AKC)
      Rotterdam, South Holland, Netherlands
    • University Medical Center Utrecht
      Utrecht, Utrecht, Netherlands
  • 2011–2013
    • The Queen Elizabeth Hospital
      • Department of Clinical Pharmacology
      Tarndarnya, South Australia, Australia
  • 1989–2013
    • Erasmus Universiteit Rotterdam
      • • Department of Clinical Chemistry
      • • Institute of Health Policy & Management (iBMG)
      • • Department of Internal Medicine
      Rotterdam, South Holland, Netherlands
  • 2012
    • Catholic University of Louvain
      • Louvain Centre for Toxicology and Applied Pharmacology
      Louvain-la-Neuve, WAL, Belgium
  • 2010
    • Universitair Ziekenhuis Leuven
      Louvain, Flanders, Belgium
  • 2001–2004
    • Stanford Medicine
      • Department of Cardiothoracic Surgery
      Stanford, California, United States
    • Hospital of the University of Pennsylvania
      • Department of Pathology and Laboratory Medicine
      Philadelphia, Pennsylvania, United States
    • Radboud University Nijmegen
      • Department of Nephrology
      Nijmegen, Provincie Gelderland, Netherlands
  • 2000–2004
    • Stanford University
      • • Department of Cardiothoracic Surgery
      • • Division of Cardiovascular Medicine
      Stanford, CA, United States
  • 1997
    • Kyoto Prefectural University of Medicine
      Kioto, Kyōto, Japan
  • 1993
    • Netherlands Cancer Institute
      Amsterdamo, North Holland, Netherlands