Jan Willem Cohen Tervaert

Sheba Medical Center, Ramat Gan, Tel Aviv, Israel

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Publications (96)675.43 Total impact

  • Article: Induction of remission in active anti-neutrophil cytoplasmic antibody-associated vasculitis with mycophenolate mofetil in patients who cannot be treated with cyclophosphamide.
    Patricia M Stassen, Jan Willem Cohen Tervaert, Coen A Stegeman
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    ABSTRACT: Active anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is commonly treated with cyclophosphamide, a drug with serious side effects, and with corticosteroids. To determine the efficacy of a possible alternative drug for cyclophosphamide, oral mycophenolate mofetil (MMF) 1000 mg twice daily and oral prednisolone 1 mg/kg once daily as remission induction treatment. 32 consecutive patients with 34 episodes of active vasculitis who could not be treated with cyclophosphamide were diagnosed for a median (range) of 6.0 (0.3-22) years and experienced 4 (0-14) relapses prior to the current episode. Treatment response and relapse-free survival were analysed. Complete remission (CR) was obtained in 25 (78%) patients, partial remission (PR) in 6 (19%), whereas 1 (3%) patient did not respond. 19 patients relapsed, 13 (52%) after CR, 14 (3-58) months after starting the treatment and 6 (100%) after PR, 6 (2-10) months after starting the treatment. The median relapse-free survival was 16 months, comparable with the interval between the previous relapse and the current MMF-treated relapse (17 (3-134) months). Relapse-free survival at 1, 3, and 5 years was 63%, 38% and 27%, respectively. Patients who had been treated successfully with cyclophosphamide before responded better (CR 84%, relapse 50%) than those who had not (CR 50%, relapse 100%). Minor gastrointestinal side effects and infections occurred frequently. MMF was prematurely discontinued due to adverse effects in two patients. MMF, in combination with prednisolone, can induce remission in patients with relapses of AAV intolerant to cyclophosphamide.
    Annals of the Rheumatic Diseases 07/2007; 66(6):798-802. · 8.73 Impact Factor
  • Article: EULAR recommendations for conducting clinical studies and/or clinical trials in systemic vasculitis: focus on anti-neutrophil cytoplasm antibody-associated vasculitis.
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    ABSTRACT: To develop the European League Against Rheumatism (EULAR) recommendations for conducting clinical studies and/or clinical trials in systemic vasculitis. An expert consensus group was formed consisting of rheumatologists, nephrologists and specialists in internal medicine representing five European countries and the USA, a clinical epidemiologist and representatives from regulatory agencies. Using an evidence-based and expert opinion-based approach in accordance with the standardised EULAR operating procedures, the group identified nine topics for a systematic literature search through a modified Delphi technique. On the basis of research questions posed by the group, recommendations were derived for conducting clinical studies and/or clinical trials in systemic vasculitis. Based on the results of the literature research, the expert committee concluded that sufficient evidence to formulate guidelines on conducting clinical trials was available only for anti-neutrophil cytoplasm antibody-associated vasculitides (AAV). It was therefore decided to focus the recommendations on these diseases. Recommendations for conducting clinical trials in AAV were elaborated and are presented in this summary document. It was decided to consider vasculitis-specific issues rather than general issues of trial methodology. The recommendations deal with the following areas related to clinical studies of vasculitis: definitions of disease, activity states, outcome measures, eligibility criteria, trial design including relevant end points, and biomarkers. A number of aspects of trial methodology were deemed important for future research. On the basis of expert opinion, recommendations for conducting clinical trials in AAV were formulated. Furthermore, the expert committee identified a strong need for well-designed research in non-AAV systemic vasculitides.
    Annals of the Rheumatic Diseases 06/2007; 66(5):605-17. · 8.73 Impact Factor
  • Article: Pneumococcal vaccination does not increase circulating levels of IgM antibodies to oxidized LDL in humans and therefore precludes an anti-atherogenic effect.
    Jan Damoiseaux, Ger Rijkers, Jan Willem Cohen Tervaert
    Atherosclerosis 02/2007; 190(1):10-1. · 3.79 Impact Factor
  • Article: TNF-alpha bioactivity-inhibiting therapy in ANCA-associated vasculitis: clinical and experimental considerations.
    Dennis Huugen, Jan Willem Cohen Tervaert, Peter Heeringa
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    ABSTRACT: Wegener's granulomatosis, microscopic polyangiitis, idiopathic necrotizing crescentic glomerulonephritis, and Churg-Strauss syndrome are associated with the presence of ANCA with specificity for myeloperoxidase or proteinase 3. Current therapy consists mainly of corticosteroids and cyclophosphamide, but because this treatment regimen is associated with considerable morbidity, other treatment modalities remain desirable. There is compelling evidence that TNF-alpha plays an important role in the pathogenesis of ANCA-associated vasculitis. Consequently, inhibition of TNF-alpha bioactivity potentially results in attenuation of disease. This review discusses whether TNF-alpha bioactivity-inhibiting drugs are useful in the treatment of ANCA-associated vasculitis. The results of in vitro and in vivo experiments, as well as clinical studies, are evaluated. Although the importance of TNF-alpha during lesion development is evident, clinical trials that use TNF-alpha blockers in patients with ANCA-associated vasculitis give mixed results. Importantly, in a large-scale, randomized trial, treatment with etanercept was found not to be effective and resulted in an excess of treatment-related morbidity. It remains to be investigated whether inhibition of TNF-alpha bioactivity is effective in a subgroup of patients.
    Clinical Journal of the American Society of Nephrology 10/2006; 1(5):1100-7. · 5.23 Impact Factor
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    Article: Evaluation of antibodies against human HSP60 in patients with MPO-ANCA associated glomerulonephritis: a cohort study.
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    ABSTRACT: Human Heat Shock Protein 60 (hHSP60) has been implicated in autoimmunity through molecular mimicry, based on the high degree of homology with HSP65 of micro-organisms leading to autoimmune recognition of the human protein. Additionally, sequence homology between hHSP60 and myeloperoxidase (MPO) has been described. MPO is a major autoantigen in vasculitis associated with antineutrophil cytoplasmic antibodies (ANCA). We hypothesized that infections may trigger the ANCA response against MPO through hHSP60. In 86 consecutive patients with ANCA-associated vasculitis (AAV), anti-hHSP60 and anti-mycobacterial HSP65 were measured by ELISA. Patients were compared with 69 healthy controls (HC). Continuous data between groups were compared using Wilcoxon signed rank test and Kruskal-Wallis test with Dunn's post-test when appropriate. Correlations between data were derived using Spearman correlation. Odds ratios and 95% confidence intervals were obtained using Fisher's exact test. At diagnosis, median anti-mHSP65 level was higher in AAV (median [range]: 42.5 [0-500]), and subsequently in MPO-ANCA (44 [7-500]), compared to HC (22 [0-430]). Anti-hHSP60 levels in AAV were not higher compared to HC (18 [0-319] and 18.5 [0-98], respectively). However, in MPO-ANCA anti-hHSP60 levels were increased (32.5 [0-319]) compared to PR3-ANCA (13 [0-79]) and HC. We could not detect cross-reactivity between hHSP60 and MPO-ANCA. There was a correlation between anti-mHSP65 and anti-hHSP60 levels (r = 0.32, P = 0.003) but not between anti-hHSP60 and MPO-ANCA (r = -0.064, P = 0.69). Antibodies against mHSP65 are higher in AAV compared to HC, and anti-hHSP60 antibodies are higher in patients with MPO-ANCA than in patients with PR3-ANCA and HC. Although this finding may be indicative for cross-reactivity between MPO-ANCA and hHSP60, additional assays did not support this hypothesis.
    Journal of Autoimmune Diseases 02/2006; 3:4.
  • Article: F.56. Clinical Associations of the -129 and -463 Myeloperoxidase Promoter Polymorphism in Mexican Patients with Systemic Lupus Erythematosus
    Clinical Immunology - CLIN IMMUNOL. 01/2006; 119.
  • Article: Anti-neutrophil cytoplasmic autoantibodies and leukocyte-endothelial interactions: a sticky connection?
    Peter Heeringa, Dennis Huugen, Jan Willem Cohen Tervaert
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    ABSTRACT: Anti-neutrophil cytoplasmic autoantibodies (ANCA) with specificity for myeloperoxidase (MPO) or proteinase 3 (Pr3) are associated with systemic small-vessel vasculitides (SVV). Detection of ANCA is an established clinical tool in disease diagnosis and monitoring. Based on clinical and in vitro experimental evidence, a pathogenic role for ANCA has long been suspected, however, in vivo models in which causality can be tested have been lacking. Recently, an exciting novel rat model of MPO-ANCA-associated vasculitis has been described, which provides compelling evidence that MPO-ANCA are a primary pathogenic factor in SVV by augmenting leukocyte-endothelial interactions and vascular wall damage.
    Trends in Immunology 12/2005; 26(11):561-4. · 10.40 Impact Factor
  • Article: Coexistence of anti-glomerular basement membrane antibodies and myeloperoxidase-ANCAs in crescentic glomerulonephritis.
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    ABSTRACT: In a substantial proportion of patients with crescentic glomerulonephritis (CGN), both anti-glomerular basement membrane (GBM) antibodies and antineutrophil cytoplasmic antibodies (ANCAs) with specificity for myeloperoxidase (MPO-ANCA) are detected. In the present study, we questioned whether histological and clinical features of patients with both ANCA and anti-GBM antibodies differ from those of patients with either ANCA or anti-GBM alone. We reviewed the Limburg renal biopsy registry (1978 to 2003; n = 1,373) for cases of CGN. The presence of linear fluorescence on renal biopsy and the presence of ANCA and/or anti-GBM antibodies were measured. Subsequently, we assessed patient characteristics and follow-up and compared histological findings among the different groups. We identified 46 MPO-ANCA-positive, 10 double-positive, and 13 anti-GBM-positive patients. Mean ages were 63, 64, and 52 years (P = 0.04), and serum creatinine levels were 5.0, 10.3, and 9.6 mg/dL (445, 910, and 850 micromol/L), respectively (P = 0.01). Granulomatous periglomerular inflammation was found in either MPO-ANCA- or double-positive patients, but not in anti-GBM-positive patients with CGN without MPO-ANCAs. Patient survival among the 3 groups was different, although not statistically significant (log rank P = 0.17, with 75%, 79%, and 100% alive at 1 year, respectively). Renal survival analysis showed significant differences among the 3 groups (P = 0.04, with 65%, 10%, and 15% off dialysis therapy at 1 year, respectively). In patients with both anti-GBM antibodies and MPO-ANCAs, histological findings differ from those of patients with anti-GBM antibodies only. However, renal survival in these patients is not better than that in anti-GBM-positive patients and is worse compared with patients with MPO-ANCAs only.
    American Journal of Kidney Diseases 09/2005; 46(2):253-62. · 5.43 Impact Factor
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    Article: Randomized trial of cyclophosphamide versus methotrexate for induction of remission in early systemic antineutrophil cytoplasmic antibody-associated vasculitis.
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    ABSTRACT: Standard therapy for antineutrophil cytoplasmic antibody-associated systemic vasculitis (AASV) with cyclophosphamide (CYC) and prednisolone is limited by toxicity. This unblinded, prospective, randomized, controlled trial was undertaken to determine whether methotrexate (MTX) could replace CYC in the early treatment of AASV. Patients with newly diagnosed AASV, with serum creatinine levels <150 mumoles/liter, and without critical organ manifestations of disease were randomized to receive either standard oral CYC, 2 mg/kg/day or oral MTX, 20-25 mg/week; both groups received the same prednisolone regimen. All drug treatments were gradually tapered and withdrawn by 12 months. Followup continued to 18 months. The primary end point was the remission rate at 6 months (noninferiority testing). One hundred patients were recruited from 26 European centers; 51 patients were randomized to the MTX group and 49 to the CYC group. At 6 months, the remission rate in patients treated with MTX (89.8%) was not inferior to that in patients treated with CYC (93.5%) (P = 0.041). In the MTX group, remission was delayed among patients with more extensive disease (P = 0.04) or pulmonary involvement (P = 0.03). Relapse rates at 18 months were 69.5% in the MTX group and 46.5% in the CYC group; the median time from remission to relapse was 13 months and 15 months, respectively (P = 0.023, log rank test). Two patients from each group died. Adverse events (mean 0.87 episodes/patient) included leukopenia, which was less frequent in the MTX versus the CYC group (P = 0.012), and liver dysfunction, which was more frequent in the MTX group (P = 0.036). MTX can replace CYC for initial treatment of early AASV. The MTX regimen used in the present study was less effective for induction of remission in patients with extensive disease and pulmonary involvement and was associated with more relapses than the CYC regimen after termination of treatment. The high relapse rates in both treatment arms support the practice of continuation of immunosuppressive treatment beyond 12 months.
    Arthritis & Rheumatism 09/2005; 52(8):2461-9. · 7.87 Impact Factor
  • Article: Aggravation of anti-myeloperoxidase antibody-induced glomerulonephritis by bacterial lipopolysaccharide: role of tumor necrosis factor-alpha.
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    ABSTRACT: Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, and idiopathic pauci-immune necrotizing crescentic glomerulonephritis are associated with myeloperoxidase (MPO)-specific anti-neutrophil cytoplasmic autoantibodies (ANCAs). Clinical and experimental evidence indicates that ANCA and proinflammatory stimuli of infectious origin act synergistically to cause vasculitis. We tested this hypothesis in a recently developed mouse model of anti-MPO IgG-induced glomerulonephritis by using bacterial lipopolysaccharide (LPS) as the proinflammatory stimulus. Systemic administration of LPS dose dependently increased renal injury induced by anti-MPO IgG as demonstrated by increased glomerular crescent formation and glomerular necrosis. In the early phase, LPS enhanced anti-MPO IgG-induced glomerular neutrophil accumulation. Furthermore, a transient induction of circulating tumor necrosis factor (TNF)-alpha levels, followed by a marked increase in circulating MPO levels, was observed on administration of LPS. In vitro, anti-MPO IgG induced a respiratory burst in murine neutrophils only after priming with TNF-alpha. Finally, anti-TNF-alpha treatment attenuated, but did not prevent, the LPS-mediated aggravation of anti-MPO IgG-induced glomerulonephritis. In conclusion, our study demonstrates that ANCA and proinflammatory stimuli act synergistically to induce vasculitic disease and suggests potential benefits of inhibiting TNF-alpha bioactivity in treating human ANCA-associated necrotizing crescentic glomerulonephritis.
    American Journal Of Pathology 08/2005; 167(1):47-58. · 4.89 Impact Factor
  • Article: Occurrence of antineutrophil cytoplasmic antibodies and associated vasculitis in patients with hyperthyroidism treated with antithyroid drugs: A long-term followup study.
    Marjan C Slot, Thera P Links, Coen A Stegeman, Jan Willem Cohen Tervaert
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    ABSTRACT: To test whether antineutrophil cytoplasmic antibodies (ANCA) and ANCA-associated vasculitis (AAV) are not only induced during treatment with antithyroid drugs, but can also become evident when medication has been ceased, possibly after years. Patients who visited our hospital for the treatment of hyperthyroidism were included (n = 207). Treatment consisted of antithyroid medications, radioactive iodide, thyroidectomy, or a combination of these treatment options. Patients were retested 3-6 years later to evaluate long-term effects of antithyroid drugs. Patients were tested for the presence of ANCA and, if positive, evaluated for the presence of AAV. Of 209 patients with hyperthyroidism, 12 patients (6%) were positive for myeloperoxidase- (MPO-), proteinase 3-, or human leukocyte elastase-ANCA. Seventy-seven of 209 patients were retested; 1 patient who had not been treated with antithyroid drugs had developed MPO-ANCA. In 3 of 6 patients previously positive, ANCA could still be detected. The presence of ANCA was highly associated with treatment with antithyroid drugs (odds ratio 11.8 [95% confidence interval 1.5-93.3]). Of 13 patients with a positive ANCA result on enzyme-linked immunosorbent assay, AAV with glomerulonephritis was diagnosed in 4 (31%). The presence of ANCA with or without vasculitis is associated with previous treatment with antithyroid drugs, possibly after years.
    Arthritis & Rheumatism 03/2005; 53(1):108-13. · 7.87 Impact Factor
  • Article: Signs and symptoms of thin basement membrane nephropathy: a prospective regional study on primary glomerular disease-The Limburg Renal Registry.
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    ABSTRACT: To chart the epidemiology of primary glomerular disease by means of a prospective regional study in the southern part of The Netherlands. Experienced renal technicians collected renal biopsies, blood, and 24-hour urine samples at the bed site in each of the participating hospitals. The material was processed and analyzed at the University Hospital Maastricht. Analysis included light microscopy, immunohistochemistry, and electron microscopy of the biopsies as well as serologic and chemical analysis. Primary IgA nephropathy (IgAN), membranous glomerulopathy, antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis and thin basement membrane nephropathy (TBMN) are the most common primary glomerular diseases in this order of sequence. Our data show the clinical and histologic phenotype of TBMN to be diverse: the vast majority of TBMN has chronic microscopic hematuria, frequently associated with hypertension in late middle age; about 15% of TBMN has in addition substantial proteinuria which is associated in the majority of cases with the lesions of focal segmental glomerulosclerosis (FSGS). In 5% of TBMN a nephrotic syndrome is observed, occasionally associated with FSGS tip lesions. These results support the notion that TBMN is a disease of genetic heterogeneity; it is not a benign renal condition in a substantial number of patients, particularly those in late middle age.
    Kidney International 10/2004; 66(3):909-13. · 6.61 Impact Factor
  • Article: ANCA-GBM dot-blot: evaluation of an assay in the differential diagnosis of patients presenting with rapidly progressive glomerulonephritis.
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    ABSTRACT: Rapidly progressive glomerulonephritis (RPGN) is characterized by rapid and progressive loss of renal function and the presence of crescentic glomerulonephritis (CGN). Early diagnosis and appropriate treatment is mandatory to prevent death and/or renal failure. We have evaluated an ANCA-GBM dot-blot diagnostic test in terms of sensitivity, specificity, and inter-observer effect in consecutive patients with RPGN ( n = 82). Control sera ( n = 34) included healthy and relevant disease controls. Dot-blots were independently evaluated by nine observers. Proteinase 3 (PR3)-ANCA, myeloperoxidase (MPO)-ANCA, and both were detected by ELISA in 36, 32, and 3 samples of 71 patients with pauci-immune CGN, respectively. Two additional samples were ANCA negative. The dot-blot revealed a sensitivity of 92-95% for PR3-ANCA and 80-86% for MPO-ANCA. The specificity of the dot-blot for PR3- and MPO-ANCA was 100%. In the patients with anti-GBM nephritis ( n = 9) anti-GBM was detected by both ELISA and dot-blot (sensitivity: 100%). The specificity of the anti-GBM dot-blot was 91-94%. However, the inter-observer effect was relatively high for detection of anti-GBM antibodies (24%). In conclusion, the ANCA-GBM dot-blot is a useful screening tool in situations where conventional ANCA testing is not readily available with excellent performance for PR3-ANCA detection, but less optimal sensitivity for MPO-ANCA and specificity for anti-GBM detection. Therefore, it is recommended to include the following advises in the report to the physicians: 1) patients with a high clinical suspicion for MPO-ANCA-associated RPGN and negative dot-blot must have conventional analysis for MPO-ANCA, and 2) negative anti-GBM dot-blot makes anti-GBM disease very unlikely, but positive samples should be confirmed by conventional anti-GBM tests.
    Journal of Clinical Immunology 08/2004; 24(4):435-40. · 3.08 Impact Factor
  • Article: Wegener's granulomatosis.
    Marjan C Slot, Jan Willem Cohen Tervaert
    Autoimmunity 07/2004; 37(4):313-5. · 2.47 Impact Factor
  • Article: Positive classic antineutrophil cytoplasmic antibody (C-ANCA) titer at switch to azathioprine therapy associated with relapse in proteinase 3-related vasculitis.
    Marjan C Slot, Jan Willem Cohen Tervaert, Maarten M Boomsma, Coen A Stegeman
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    ABSTRACT: To analyze disease-free survival in patients with antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitis (AAV) treated with cyclophosphamide only or switched to azathioprine after 3 months of full remission while taking cyclophosphamide. We analyzed disease-free survival in all consecutive patients diagnosed with AAV between 1990 and 2000 at our center. Patients were treated with cyclophosphamide only (1990-1996) or switched to azathioprine after 3 months of remission while taking cyclophosphamide (1997-2000). All patients received at least 12 months of followup. Of the total 128 patients, 53 (41%) relapsed. Forty-four of the 128 patients (34%) had been switched to azathioprine therapy. Disease-free survival at 2 and 4 years was 76% and 65% in the cyclophosphamide group compared with 76% and 51% in the azathioprine group. In patients with proteinase 3 (PR3) classic ANCA (C-ANCA)-associated vasculitis who were switched to azathioprine (n = 33), a positive C-ANCA titer at the moment of treatment switch (n = 13) was significantly associated with relapse (RR 2.6, 95% confidence interval 1.1-8.0; P = 0.04). In patients with a negative ANCA titer at the time of switch to azathioprine, disease-free survival at 2 and 4 years was 80% and 62%, which was identical to that for patients treated with cyclophosphamide only. In patients who were ANCA-positive at the time of treatment switch, disease-free survival at 2 and 4 years was only 58% and 17%. Switching cyclophosphamide to azathioprine after induction of remission in patients with PR3-ANCA-associated vasculitis who are still ANCA-positive at the time of treatment switch is associated with a high risk of relapse.
    Arthritis & Rheumatism 05/2004; 51(2):269-73. · 7.87 Impact Factor
  • Article: Antineutrophil cytoplasmic autoantibodies and pathophysiology: new insights from animal models.
    Dennis Huugen, Jan Willem Cohen Tervaert, Peter Heeringa
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    ABSTRACT: PURPOSE OF REVIEW: Since the discovery of antineutrophil cytoplasmic autoantibodies (ANCA) and their association with the occurrence of several types of small-vessel vasculitis, a causal relation between the two has been suggested. Various in vitro and in vivo experimental data provide indirect evidence in support of this view. This article comprises a review of the animal models that have been used to investigate the pathogenesis of ANCA-associated vasculitis, and focuses on recent developments in this field. RECENT FINDINGS: Xiao et al. provide definite proof of the pathogenic potential of ANCA in a novel mouse model of myeloperoxidase (MPO)-ANCA-associated vasculitis, in which transfer of splenocytes or IgG from MPO-/- mice immunized with murine MPO, to naive wild-type or Rag2-/- (lacking mature B and T lymphocytes) mice causes a disease remarkably similar to its human counterpart. In addition, preliminary studies by Smyth et al. show that immunization of Wistar Kyoto rats with human MPO induces antihuman MPO antibodies that cross-react with rat MPO, as well as a disease closely resembling human small-vessel vasculitis. Another murine ANCA model is the SCG/Kj mouse. A recent publication by Neumann et al., however, puts an important limitation on the use of this mouse model for the study of ANCA-associated vasculitis, demonstrating multiple immune complex deposits in the spontaneously occurring vascular lesions. SUMMARY Recently developed animal models of MPO-ANCA-associated vasculitis convincingly demonstrate that MPO-ANCA are pathogenic. Whether similar strategies can be used to develop an appropriate model for proteinase 3-ANCA-associated vasculitis remains to be investigated.
    Current Opinion in Rheumatology 02/2004; 16(1):4-8. · 4.31 Impact Factor
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    Article: Neutrophil myeloperoxidase activity and the influence of two single-nucleotide promoter polymorphisms.
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    ABSTRACT: Myeloperoxidase (MPO) catalyses the formation of hypochlorous acid and is involved in many (patho)physiological processes. The present study was designed to determine the effect of two MPO promoter polymorphisms (463G/A and 129G/A) on enzyme activity. In 243 healthy controls, genotypes were determined and MPO activity was measured on a single-cell level using a haematological analyser. The 129G/A polymorphism reduces MPO activity in neutrophils, whereas for the 463G/A polymorphism, only gender-dependent differences in MPO activity in older age groups could be found. When studying these polymorphisms in disease, therefore, age and gender should be included in the analysis.
    British Journal of Haematology 12/2003; 123(3):536-8. · 4.94 Impact Factor
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    Article: Neutrophil myeloperoxidase activity and the influence of two single‐nucleotide promoter polymorphisms
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    ABSTRACT:   Myeloperoxidase (MPO) catalyses the formation of hypochlorous acid and is involved in many (patho)physiological processes. The present study was designed to determine the effect of two MPO promoter polymorphisms (463G/A and 129G/A) on enzyme activity. In 243 healthy controls, genotypes were determined and MPO activity was measured on a single-cell level using a haematological analyser. The 129G/A polymorphism reduces MPO activity in neutrophils, whereas for the 463G/A polymorphism, only gender-dependent differences in MPO activity in older age groups could be found. When studying these polymorphisms in disease, therefore, age and gender should be included in the analysis.
    British Journal of Haematology 10/2003; 123(3):536 - 538. · 4.94 Impact Factor
  • Article: A randomized trial of maintenance therapy for vasculitis associated with antineutrophil cytoplasmic autoantibodies.
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    ABSTRACT: The primary systemic vasculitides usually associated with autoantibodies to neutrophil cytoplasmic antigens include Wegener's granulomatosis and microscopic polyangiitis. We investigated whether exposure to cyclophosphamide in patients with generalized vasculitis could be reduced by substitution of azathioprine at remission. We studied patients with a new diagnosis of generalized vasculitis and a serum creatinine concentration of 5.7 mg per deciliter (500 micromol per liter) or less. All patients received at least three months of therapy with oral cyclophosphamide and prednisolone. After remission, patients were randomly assigned to continued cyclophosphamide therapy (1.5 mg per kilogram of body weight per day) or a substitute regimen of azathioprine (2 mg per kilogram per day). Both groups continued to receive prednisolone and were followed for 18 months from study entry. Relapse was the primary end point. Of 155 patients studied, 144 (93 percent) entered remission and were randomly assigned to azathioprine (71 patients) or continued cyclophosphamide (73 patients). There were eight deaths (5 percent), seven of them during the first three months. Eleven relapses occurred in the azathioprine group (15.5 percent), and 10 occurred in the cyclophosphamide group (13.7 percent, P=0.65). Severe adverse events occurred in 15 patients during the induction phase (10 percent), in 8 patients in the azathioprine group during the remission phase (11 percent), and in 7 patients in the cyclophosphamide group during the remission phase (10 percent, P=0.94 for the comparison between groups during the remission phase). The relapse rate was lower among the patients with microscopic polyangiitis than among those with Wegener's granulomatosis (P=0.03). In patients with generalized vasculitis, the withdrawal of cyclophosphamide and the substitution of azathioprine after remission did not increase the rate of relapse. Thus, the duration of exposure to cyclophosphamide may be safely reduced.
    New England Journal of Medicine 08/2003; 349(1):36-44. · 53.30 Impact Factor
  • Article: Laboratory assessment in musculoskeletal disorders.
    Pieter van Paassen, Jan Damoiseaux, Jan Willem Cohen Tervaert
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    ABSTRACT: Autoimmune-mediated musculoskeletal disorders feature the presence and pathogenic role of circulating autoantibodies and autoreactive T cells. Determination of these autoantibodies provides crucial information to establish the diagnosis of these diseases. In addition, the determination of these antibodies may have prognostic value or may be used to monitor response to treatment or to predict relapse of disease. We first address the main characteristics of several autoantibody assays that are considered to be clinically most relevant. These include rheumatoid factor (RF), anti-cyclic citrullinated antibody (anti-CCP), antinuclear autoantibodies (ANA), anti-double-stranded DNA antibodies, antibodies to extractable nuclear antigens (ENA), and antineutrophil cytoplasmic autoantibodies (ANCA). Subsequently we provide a brief overview of the most important musculoskeletal disorders, such as rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis/CREST, polymyositis/dermatomyositis and vasculitis. Our main goal was to address the role of the determination of autoantibodies in the diagnosis and follow-up of musculoskeletal disorders.
    Bailli&egrave re s Best Practice and Research in Clinical Rheumatology 07/2003; 17(3):475-94. · 2.65 Impact Factor

Institutions

  • 2009–2012
    • Sheba Medical Center
      Ramat Gan, Tel Aviv, Israel
  • 2002–2012
    • Maastricht Universitair Medisch Centrum
      Maastricht, Provincie Limburg, Netherlands
  • 2009–2011
    • Tel Aviv University
      Tel Aviv, Tel Aviv, Israel
  • 2002–2011
    • Maastricht University
      • • MHeNS School for Mental Health and Neuroscience
      • • Interne Geneeskunde
      Maastricht, Provincie Limburg, Netherlands
  • 1994–2007
    • University of Groningen
      • • Department of Nephrology
      • • Department of Rheumatology and Clinical Immunology
      • • Department of Internal Medicine
      Groningen, Province of Groningen, Netherlands
  • 2002–2005
    • Universitair Medisch Centrum Groningen
      Groningen, Province of Groningen, Netherlands