Jack F M Wetzels

Bridgeport Hospital, Bridgeport, Connecticut, United States

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Publications (375)1959.66 Total impact

  • Julia M. Hofstra · Jack F.M. Wetzels
    No preview · Article · May 2016
  • [Show abstract] [Hide abstract] ABSTRACT: Background: Early detection and appropriate management of chronic kidney disease (CKD) in primary care are essential to reduce morbidity and mortality. Aim: To assess the quality of care (QoC) of CKD in primary healthcare in relation to patient and practice characteristics in order to tailor improvement strategies. Design and setting: Retrospective study using data between 2008 and 2011 from 47 general practices (207 469 patients of whom 162 562 were adults). Method: CKD management of patients under the care of their general practitioner (GP) was qualified using indicators derived from the Dutch interdisciplinary CKD guideline for primary care and nephrology and included (1) monitoring of renal function, albuminuria, blood pressure, and glucose, (2) monitoring of metabolic parameters, and alongside the guideline: (3) recognition of CKD. The outcome indicator was (4) achieving blood pressure targets. Multilevel logistic regression analysis was applied to identify associated patient and practice characteristics. Results: Kidney function or albuminuria data were available for 59 728 adult patients; 9288 patients had CKD, of whom 8794 were under GP care. Monitoring of disease progression was complete in 42% of CKD patients, monitoring of metabolic parameters in 2%, and blood pressure target was reached in 43.1%. GPs documented CKD in 31.4% of CKD patients. High QoC was strongly associated with diabetes, and to a lesser extent with hypertension and male sex. Conclusion: Room for improvement was found in all aspects of CKD management. As QoC was higher in patients who received structured diabetes care, future CKD care may profit from more structured primary care management, e.g. according to the chronic care model.
    No preview · Article · Feb 2016 · Scandinavian Journal of Primary Health Care
  • [Show abstract] [Hide abstract] ABSTRACT: Vitamin D plays an important role in renal (patho)physiology. Patients with glomerular diseases have an injured renal filtration barrier, leading to proteinuria and, eventually, reduced renal function. An impaired renal function also leads to 1,25-vitamin D3 deficiency as a result of reduced renal 1α-hydroxylase activity. Vitamin D treatment to reduce proteinuria remains controversial, although there is an inverse correlation between vitamin D levels and the occurrence of proteinuria. Herein, we showed that 1,25-vitamin D3-deficient 25-hydroxy-vitamin-D3-1α-hydroxylase knockout mice and 1,25-vitamin D3-deficient rats develop podocyte injury and renal dysfunction. Glomerular injury was characterized by proteinuria and partial podocyte foot process effacement. Expression of nephrin, podocin, desmin, and transient receptor potential channel C6 in the podocyte was significantly altered in 1,25-vitamin D3-deficient animals. Supplementation with 1,25-vitamin D3 or 1,25-vitamin D2 prevented podocyte effacement or reversed glomerular and tubulointerstitial damage in 1,25-vitamin D3-deficient animals, thereby preserving and restoring renal function, respectively. The effect of 1,25-vitamin D3 deficiency and 1,25-vitamin D3 and 1,25-vitamin D2 repletion on proteinuria could not be explained by hypocalcemia, changes in parathyroid hormone, or fibroblast growth factor 23. This study demonstrates that 1,25-vitamin D3 deficiency directly leads to renal injury in rodents. When translated to human subjects, this would underline the need for early vitamin D supplementation in patients with glomerular disease and chronic renal insufficiency, which might inhibit or potentially reverse renal injury.
    No preview · Article · Feb 2016 · American Journal Of Pathology
  • No preview · Article · Jan 2016 · American Journal of Kidney Diseases
  • [Show abstract] [Hide abstract] ABSTRACT: Urinary hepcidin may have protective effects against AKI. However, renal handling and the potential protective mechanisms of hepcidin are not fully understood. By measuring hepcidin levels in plasma and urine using mass spectrometry and the kidney using immunohistochemistry after intraperitoneal administration of human hepcidin-25 (hhep25) in C57Bl/6N mice, we showed that circulating hepcidin is filtered by the glomerulus and degraded to smaller isoforms detected in urine but not plasma. Moreover, hepcidin colocalized with the endocytic receptor megalin in proximal tubules, and compared with wild-type mice, megalin-deficient mice showed higher urinary excretion of injected hhep25 and no hepcidin staining in proximal tubules that lack megalin. This indicates that hepcidin is reaborbed in the proximal tubules by megalin dependent endocytosis. Administration of hhep25 concomitant with or 4 hours after a single intravenous dose of hemoglobin abolished hemoglobin-induced upregulation of urinary kidney injury markers (NGAL and KIM-1) and renal Interleukin-6 and Ngal mRNA observed 24 hours after administration but did not affect renal ferroportin expression at this point. Notably, coadministration of hhep25 and hemoglobin but not administration of either alone greatly increased renal mRNA expression of hepcidin-encoding Hamp1 and hepcidin staining in distal tubules. These findings suggest a role for locally synthesized hepcidin in renal protection. Our observations did not support a role for ferroportin in hhep25-mediated protection against hemoglobin-induced early injury, but other mechanisms of cellular iron handling may be involved. In conclusion, our data suggest that both systemically delivered and locally produced hepcidin protect against hemoglobin-induced AKI.
    No preview · Article · Jan 2016 · Journal of the American Society of Nephrology
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    [Show abstract] [Hide abstract] ABSTRACT: The bioartificial kidney (BAK) aims at improving dialysis by developing 'living membranes' for cells-aided removal of uremic metabolites. Here, unique human conditionally immortalized proximal tubule epithelial cell (ciPTEC) monolayers were cultured on biofunctionalized MicroPES (polyethersulfone) hollow fiber membranes (HFM) and functionally tested using microfluidics. Tight monolayer formation was demonstrated by abundant zonula occludens-1 (ZO-1) protein expression along the tight junctions of matured ciPTEC on HFM. A clear barrier function of the monolayer was confirmed by limited diffusion of FITC-inulin. The activity of the organic cation transporter 2 (OCT2) in ciPTEC was evaluated in real-time using a perfusion system by confocal microscopy using 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP(+)) as a fluorescent substrate. Initial ASP(+) uptake was inhibited by a cationic uremic metabolites mixture and by the histamine H2-receptor antagonist, cimetidine. In conclusion, a 'living membrane' of renal epithelial cells on MicroPES HFM with demonstrated active organic cation transport was successfully established as a first step in BAK engineering.
    Full-text · Article · Nov 2015 · Scientific Reports
  • No preview · Article · Nov 2015 · American Journal of Kidney Diseases
  • Jaap Deinum · Jack F M Wetzels
    No preview · Article · Nov 2015 · The Lancet
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    [Show abstract] [Hide abstract] ABSTRACT: Complement C5 inhibitor eculizumab treatment in atypical hemolytic uremic syndrome is effective, but associated with high costs. Complement inhibition monitoring in these patients has not been standardized. In this study we evaluated novel functional assays for application in routine follow-up. We documented that the Wieslab® complement screen assay showed a sensitivity of 1-2% of C5 activity by adding purified C5 or normal human serum to a C5 deficient serum. All the patient samples obtained during the treatment course, were completely blocked for terminal complement pathway activity for up to four weeks after the eculizumab infusion. Levels of complexes between eculizumab and C5 were inversely correlated to the complement activity (p=0.01). Moreover, titrating serum from eculizumab-treated patients into normal serum revealed that eculizumab was present in excess up to four weeks after infusion. Thus, we demonstrate sensitive, reliable and easy-performed assays which can be used to design individual eculizumab dosage regimens.
    Full-text · Article · Sep 2015 · Clinical Immunology
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    [Show abstract] [Hide abstract] ABSTRACT: New options recently became available for treatment of uncontrolled blood pressure. Information on the prevalence of therapy-resistant hypertension (TRH) in patients with chronic kidney disease and its consequences is relevant to balance risks and benefits of potential new therapies. Data of 788 patients with chronic kidney disease came from a multicenter study investigating the effect on outcome of an integrated multifactorial approach delivered by nurse practitioners added to usual care versus usual care alone. Blood pressure was measured at the office and during 30 minutes using an automated oscillometric device. Apparent TRH (aTRH) was defined as a blood pressure ≥130/80 mm Hg despite treatment with ≥3 antihypertensive drugs, including a diuretic or treatment with ≥4 antihypertensive drugs. Participants were followed up for the occurrence of myocardial infarction, stroke or cardiovascular mortality (composite cardiovascular end point) and end-stage renal disease. aTRH was present in 34% (office blood pressure) and in 32% (automated measurements). During 5.3 years of follow-up, 17% of patients with aTRH reached a cardiovascular end point and 27% reached end-stage renal disease. aTRH lead to a 1.5-fold higher risk (95% confidence interval, 0.8-3.0) of a cardiovascular end point compared with controlled hypertensives in multivariable-adjusted analysis. aTRH increased end-stage renal disease risk 2.3-fold (95% confidence interval, 1.4-3.7). During 4 years of follow-up, the prevalence of aTRH did not decline in either treatment group. The prevalence of aTRH is high in patients with chronic kidney disease even after optimization of nephrologist care. The presence of TRH is related to a substantially increased risk of renal and cardiovascular outcomes.
    Full-text · Article · Sep 2015 · Hypertension
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    [Show abstract] [Hide abstract] ABSTRACT: Dermatan sulfate (DS), also known as chondroitin sulfate (CS)-B, is a member of the linear polysaccharides called glycosaminoglycans (GAGs). The expression of CS/DS and DS proteoglycans is increased in several fibrotic renal diseases, including interstitial fibrosis, diabetic nephropathy, mesangial sclerosis and nephrosclerosis. Little, however, is known about structural alterations in DS in renal diseases. The aim of this study was to evaluate the renal expression of two different DS domains in renal transplant rejection and glomerular pathologies. DS expression was evaluated in normal renal tissue and in kidney biopsies obtained from patients with acute interstitial or vascular renal allograft rejection, patients with interstitial fibrosis and tubular atrophy (IF/TA), and from patients with focal segmental glomerulosclerosis (FSGS), membranous glomerulopathy (MGP) or systemic lupus erythematosus (SLE), using our unique specific anti-DS antibodies LKN1 and GD3A12. Expression of the 4/2,4-di-O-sulfated DS domain recognized by antibody LKN1 was decreased in the interstitium of transplant kidneys with IF/TA, which was accompanied by an increased expression of type I collagen, decorin and transforming growth factor beta (TGF-β), while its expression was increased in the interstitium in FSGS, MGP and SLE. Importantly, all patients showed glomerular LKN1 staining in contrast to the controls. Expression of the IdoA-Gal-NAc4SDS domain recognized by GD3A12 was similar in controls and patients. Our data suggest a role for the DS domain recognized by antibody LKN1 in renal diseases with early fibrosis. Further research is required to delineate the exact role of different DS domains in renal fibrosis.
    Full-text · Article · Aug 2015 · PLoS ONE
  • Jacobien C Verhave · Anneke P Bech · Jack F M Wetzels · Tom Nijenhuis
    [Show abstract] [Hide abstract] ABSTRACT: Hepatocyte nuclear factor 1β (HNF1β)-associated disease is a recently recognized clinical entity with a variable multisystem phenotype. Early reports described an association between HNF1B mutations and maturity-onset diabetes of the young. These patients often presented with renal cysts and renal function decline that preceded the diabetes, hence it was initially referred to as renal cysts and diabetes syndrome. However, it is now evident that many more symptoms occur, and diabetes and renal cysts are not always present. The multisystem phenotype is probably attributable to functional promiscuity of the HNF1β transcription factor, involved in the development of the kidney, urogenital tract, pancreas, liver, brain, and parathyroid gland. Nephrologists might diagnose HNF1β-associated kidney disease in patients referred with a suspected diagnosis of autosomal dominant polycystic kidney disease, medullary cystic kidney disease, diabetic nephropathy, or CKD of unknown cause. Associated renal or extrarenal symptoms should alert the nephrologist to HNF1β-associated kidney disease. A considerable proportion of these patients display hypomagnesemia, which sometimes mimics Gitelman syndrome. Other signs include early onset diabetes, gout and hyperparathyroidism, elevated liver enzymes, and congenital anomalies of the urogenital tract. Because many cases of this disease are probably undiagnosed, this review emphasizes the clinical manifestations of HNF1β-associated disease for the nephrologist. Copyright © 2015 by the American Society of Nephrology.
    No preview · Article · Aug 2015 · Journal of the American Society of Nephrology
  • [Show abstract] [Hide abstract] ABSTRACT: The uremic solutes p-cresyl sulfate (pCS) and p-cresyl glucuronide (pCG) accumulate in patients with chronic kidney disease (CKD), and might contribute to disease progression. Moreover, retention of these solutes may directly be related to renal tubular function. Here, we investigated the role of the efflux transporters Multidrug Resistance Protein 4 (MRP4) and Breast Cancer Resistance Protein (BCRP) in pCS and pCG excretion, and studied the impact of both solutes on the phenotype of human conditionally immortalized renal proximal tubule epithelial cells (ciPTEC). Our results show that p-cresol metabolites accumulate during CKD, with a shift from sulfation to glucuronidation upon progression. Moreover, pCS inhibited the activity of MRP4 by 40% and BCRP by 25%, whereas pCG only reduced MRP4 activity by 75%. Moreover, BCRP-mediated transport of both solutes was demonstrated. Exposure of ciPTEC to pCG caused epithelial-to-mesenchymal transition, indicated by increased expression of vimentin and Bcl-2, and diminished E-cadherin. This was associated with altered expression of key tubular transporters. In conclusion, BCRP is likely involved in the renal excretion of both solutes, and pCG promotes phenotypical changes in ciPTEC, supporting the notion that uremic toxins may be involved in CKD progression by negatively affecting renal tubule cell phenotype and functionality.
    No preview · Article · Aug 2015 · Toxicology in Vitro
  • [Show abstract] [Hide abstract] ABSTRACT: Background: There is limited evidence to support cytotoxic therapy in patients with IgA nephropathy and renal insufficiency. We studied the effect of cytotoxic therapy in patients with IgA nephropathy and renal insufficiency, and evaluated possible predictors of response. Methods: Retrospective analysis of patients with IgA nephropathy who received immunosuppressive therapy. The primary outcome measure was progression of renal disease, defined as an increase in serum creatinine levels of ≥ 50% or development of end-stage renal disease. Results: From 1996 to 2008, 19 patients with biopsy-proven IgA nephropathy were treated with cytotoxic agents and prednisone because of renal insufficiency and÷ or severe proteinuria. Characteristics of patients at the start of therapy: age 42±11 years, serum creatinine 208 (96-490) μmol÷l, estimated glomerular filtration rate (eGFR) 33 (12-65) ml÷min÷1.73 m2, and protein- creatinine ratio 3.8 (0.6-18.2) g÷10 mmol. Follow-up after initiation of therapy was 35 (7-133) months. Ten patients had progressive renal disease, whereas eGFR was stable in nine. Serum creatinine levels and proteinuria at the start of treatment were not significantly different between responders and non- responders. Proteinuria response at six months after start of therapy proved a good predictor: proteinuria decreased by ≥ 50% and÷or reached levels below 1 g÷day in 8÷9 responders. In contrast, proteinuria decreased by more than 50% and reached levels < 1 g÷day in only 3÷10 non-responders (p < 0.01). Conclusion: Prolonged immunosuppressive therapy with cytotoxic agents and prednisone may benefit a subgroup of patients with progressive IgA nephropathy. A reduction of proteinuria ≥ 50% to levels below 1 g÷day within six months predicts a favourable long-term response.
    No preview · Article · Aug 2015 · The Netherlands Journal of Medicine
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    [Show abstract] [Hide abstract] ABSTRACT: In autosomal dominant polycystic kidney disease (ADPKD), obtaining measured total kidney volume (mTKV) by magnetic resonance (MR) imaging and manual tracing is time consuming. Two alternative MR imaging methods have recently been proposed to estimate TKV (eTKVellipsoid and eTKVPANK), which require less time. Cross-sectional and longitudinal diagnostic test study. Patients with ADPKD with a wide range of kidney function and an approved T2-weighted MR image obtained at the University Medical Centers of Groningen, Leiden, Nijmegen, and Rotterdam, the Netherlands, in 2007 to 2014. Test set for assessing reproducibility, n=10; cohort for cross-sectional analyses, n=220; and cohort for longitudinal analyses, n=48. Average times for eTKVellipsoid and eTKVPANK were 5 and 15 minutes, respectively. Bias is defined as (mTKV - eTKV)/mTKV × 100%; precision, as one standard deviation of bias. mTKV using manual tracing to calculate the area within kidney boundaries times slice thickness. Average time for mTKV was 55 minutes. In the test set, intra- and intercoefficients of variation for mTKV, eTKVellipsoid, and eTKVPANK were 1.8% and 2.3%, 3.9% and 6.3%, and 3.0% and 3.4%, respectively. In cross-sectional analysis, baseline mTKV, eTKVellipsoid, and eTKVPANK were 1.96 (IQR, 1.28-2.82), 1.93 (IQR, 1.25-2.82), and 1.81 (IQR, 1.17-2.62) L, respectively. In cross-sectional analysis, bias was 0.02% ± 3.2%, 1.4% ± 9.2%, and 4.6% ± 7.6% for repeat mTKV, eTKVellipsoid, and eTKVPANK, respectively. In longitudinal analysis, no significant differences were observed between percentage change in mTKV (16.7% ± 17.1%) and percentage change in eTKVellipsoid (19.3% ± 16.1%) and eTKVPANK (17.8% ± 16.1%) over 3 years. Results for follow-up data should be interpreted with caution because of the limited number of patients. Both methods for eTKV perform relatively well compared to mTKV and can detect change in TKV over time. Because eTKVellipsoid requires less time than eTKVPANK, we suggest that this method may be preferable in clinical care. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · Jul 2015 · American Journal of Kidney Diseases
  • M. A. G. J. ten Dam · J. F. M. Wetzels
    No preview · Article · Jul 2015 · The Netherlands Journal of Medicine
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    [Show abstract] [Hide abstract] ABSTRACT: Connective tissue growth factor (CTGF; CCN2) plays a role in the development of diabetic nephropathy (DN). Urinary CTGF (uCTGF) is elevated in DN patients and has been proposed as a biomarker for disease progression, but it is unknown which pathophysiological factors contribute to elevated uCTGF. We studied renal handling of CTGF by infusion of recombinant CTGF in diabetic mice. In addition, uCTGF was measured in type 1 DN patients and compared with glomerular and tubular dysfunction and damage markers. In diabetic mice, uCTGF was increased and fractional excretion (FE) of recombinant CTGF was substantially elevated indicating reduced tubular reabsorption. FE of recombinant CTGF correlated with excretion of endogenous CTGF. CTGF mRNA was mainly localized in glomeruli and medullary tubules. Comparison of FE of endogenous and recombinant CTGF indicated that 60% of uCTGF had a direct renal source, while 40% originated from plasma CTGF. In DN patients, uCTGF was independently associated with markers of proximal and distal tubular dysfunction and damage. In conclusion, uCTGF in DN is elevated as a result of both increased local production and reduced reabsorption due to tubular dysfunction. We submit that uCTGF is a biomarker reflecting both glomerular and tubulointerstitial hallmarks of diabetic kidney disease.
    Full-text · Article · Jul 2015 · Journal of Diabetes Research
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    [Show abstract] [Hide abstract] ABSTRACT: The Supplemental Material contains data of urinary CTGF expressed per g creatinine. Excretion of CTGF per creatinine gives comparable results as excretion expressed per 24-hour rates.
    Full-text · Dataset · Jun 2015
  • Anne-Els van de Logt · Julia M Hofstra · Jack F M Wetzels
    [Show abstract] [Hide abstract] ABSTRACT: Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published weekly online and twice a month in print.
    No preview · Article · Jun 2015 · Kidney International
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    [Show abstract] [Hide abstract] ABSTRACT: The Modification of Diet in Renal Disease (MDRD) formula is widely used in clinical practice to assess the correct drug dose. This formula is based on serum creatinine levels which might be influenced by chronic diseases itself or the effects of the chronic diseases. We conducted a systematic review to determine the validity of the MDRD formula in specific patient populations with renal impairment: elderly, hospitalized and obese patients, patients with cardiovascular disease, cancer, chronic respiratory diseases, diabetes mellitus, liver cirrhosis and human immunodeficiency virus. We searched for articles in Pubmed published from January 1999 through January 2014. Selection criteria were (1) patients with a glomerular filtration rate (GFR) < 60 ml/min (/1.73m2), (2) MDRD formula compared with a gold standard and (3) statistical analysis focused on bias, precision and/or accuracy. Data extraction was done by the first author and checked by a second author. A bias of 20% or less, a precision of 30% or less and an accuracy expressed as P30% of 80% or higher were indicators of the validity of the MDRD formula. In total we included 27 studies. The number of patients included ranged from 8 to 1831. The gold standard and measurement method used varied across the studies. For none of the specific patient populations the studies provided sufficient evidence of validity of the MDRD formula regarding the three parameters. For patients with diabetes mellitus and liver cirrhosis, hospitalized patients and elderly with moderate to severe renal impairment we concluded that the MDRD formula is not valid. Limitations of the review are the lack of considering the method of measuring serum creatinine levels and the type of gold standard used. In several specific patient populations with renal impairment the use of the MDRD formula is not valid or has uncertain validity.
    Full-text · Article · Mar 2015 · PLoS ONE

Publication Stats

8k Citations
1,959.66 Total Impact Points


  • 2013
    • Bridgeport Hospital
      Bridgeport, Connecticut, United States
  • 1985-2012
    • Radboud University Medical Centre (Radboudumc)
      • Department of Human Genetics
      Nymegen, Gelderland, Netherlands
  • 2011
    • Isala Klinieken
      • Department of Internal Medicine
      Zwolle, Overijssel, Netherlands
    • HagaZiekenhuis van Den Haag
      's-Gravenhage, South Holland, Netherlands
  • 1986-2009
    • Radboud University Nijmegen
      • • Department of Nephrology
      • • Department of General Internal Medicine
      Nymegen, Gelderland, Netherlands
    • St. Joseph's Hospital
      Savannah, Georgia, United States
  • 1998
    • University Hospital Essen
      Essen, North Rhine-Westphalia, Germany
  • 1993-1995
    • University of Colorado Hospital
      • Department of Medicine
      Denver, Colorado, United States