Effector memory T cells as driving force of granuloma formation and autoimmunity in Wegener's granulomatosis.
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Publications and source records attributed to E Csernok.
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BACKGROUND: Previous studies have shown considerable variation in diagnostic performance of enzyme linked immunosorbent assays (ELISAs) for measuring antineutrophil cytoplasmic antibodies (ANCA) specific for proteinase 3 (PR3) and myeloperoxidase (MPO). OBJECTIVE: To analyse the performance characteristics of different commercially available direct ANCA ELISA kits. METHODS: ELISA kits for detecting PR3-ANCA and MPO-ANCA from 11 manufacturers were evaluated. Serum samples were taken from patients with Wegener's granulomatosis (15), microscopic polyangiitis (15), other vasculitides (10), and controls (40). RESULTS: were compared with data obtained by indirect immunofluorescence (IFT). The diagnostic performance of the tests was analysed and compared by receiver operating characteristic (ROC) curve analysis.Results: Applying the manufacturers' cut off resulted in great variation in sensitivity of the commercial PR3-ANCA kits for diagnosing Wegener's granulomatosis (ranging from 13.3% to 66.7%), and of the MPO-ANCA kits for diagnosing microscopic polyangiitis (ranging from 26.7% to 66.7%). Specificities were relatively constant (from 96.0% to 100%). IFT was superior to all ELISAs (C-ANCA for Wegener's granulomatosis: sensitivity 73.3%, specificity 98%; P-ANCA for microscopic polyangiitis: sensitivity 86.7%, specificity 98%). The sensitivities of PR3-ANCA and MPO-ANCA ELISA kits were increased by lowering the cut off values. This reduced specificity but increased overall diagnostic performance. CONCLUSIONS: The low sensitivity of some commercial kits reflects the high cut off levels recommended rather than methodological problems with the assays. Comparative analyses using sera from well characterised patients may help identify optimum cut off levels of commercial ANCA ELISA tests, resulting in better comparability of results among assays from different manufacturers.
In antineutrophil cytoplasmatic antibody (ANCA)-associated vasculitides (AAV), bactericidal/permeability increasing protein (BPI) ANCAs are detected. Recent observations suggest that BPI-ANCAs can potentially contribute to a proinflammatory setting in the absence of proteinase 3 (PRTN3) ANCAs during the development of a pulmonary relapse by impeding the elimination of Gram-negative bacteria (GNB). However, it is as yet not clear whether the genetic background contributes to the generation of BPI-ANCAs in Wegener granulomatosis (WG) or if BPI polymorphisms are associated with WG. In this study we genotyped the functionally relevant single nucleotide polymorphism (SNP) A645 (Glu216Lys) of the BPI gene in 201 WG patients and 608 healthy controls. To investigate whether further SNPs might be associated with WG, we also examined an intragenic microsatellite marker. No significant differences were found between patients and controls. Thus BPI polymorphisms do not appear to contribute to genetic predisposition to WG. Moreover, our data do not suggest a genetic background for the generation of BPI-ANCAs in WG.
Churg-Strauss syndrome (CSS) belongs to the antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides and is further characterized by severe eosinophilia and, often, granulomatous inflammation. The therapeutic efficacy of recombinant interferon-alpha (IFN-alpha) and tumor necrosis factor-alpha (TNF-alpha) blockade point toward a central role of cytokines in the pathogenesis of CSS. Recent data show that, in contrast to other primary systemic vasculitides, peripheral blood mononuclear cells (PBMCs) secrete not only large amounts of T helper type 1 (Th1) cytokines, particularly IFN-gamma, but also release T helper type 2 (Th2) cytokines such as interleukin-4 (IL-4) and interleukin-13 (IL-13). Interleukin-5 is the most potent stimulator of eosinophil production and functional activation of mature eosinophils, the key effector cells in CSS. Data are presented showing that PBMCs from patients with CSS cultured with T cell-specific stimuli secrete significantly increased amounts of IL-5 compared with healthy controls, suggesting that IL-5 contributes substantially to the development of eosinophilia in CSS. As recombinant IFN-alpha downregulates IL-5 production of CD4(+) T cells in vitro, the increased secretion of IL-5 in patients with CSS may provide the clue for the therapeutic efficacy of recombinant IFN-alpha in the disease. Variations in the balance between Th1 and Th2 cytokines at different disease stages could contribute to the distinct clinical courses seen in patients with CSS, which can range from prominent Th1-mediated generalized vasculitis and granulomatous inflammation on one end of the spectrum to Th2-mediated systemic hypereosinophilia on the other. Although the association of ANCAs with CSS point toward an autoimmune origin of the disease, there is no direct evidence as yet for a direct pathogenic role of ANCAs in CSS.
CASE REPORTS: A 66 year old female patient had relapsing fever and non-suppurative panniculitis suggestive of enigmatic "Weber-Christian disease" (WCD). Antineutrophil cytoplasmic antibodies with specificity for human leucocyte elastase (HLE-ANCA) were detected. A biopsy showed small vessel vasculitis and panniculitis. A 53 year old man had recurrent episodes of abdominal pain, erythematous rash, and myalgia. Fever attacks had stopped a few years ago. A biopsy showed panniculitis and fasciitis. In both patients mutations (R92Q, T50M) of the tumour necrosis factor receptor super family (TNFRSF) 1A gene were disclosed. Mutations of the TNFRSF 1A gene are the cause of tumour necrosis factor receptor associated periodic syndrome (TRAPS). Both patients responded favourably to treatment with the human soluble p75 TNF alpha receptor fusion protein etanercept (2 x 25 mg subcutaneously/week). DISCUSSION: Small vessel vasculitis and panniculitis have not been reported in TRAPS so far. The cases underline the importance of TNF alpha regulation in inflammatory processes including vasculitis. Genetically determined causes of fever may account for some cases of WCD.
Anti-Neutrophil Cytoplasmic Antibodies (ANCA) are a heterogenous group of autoantibodies with a broad spectrum of clinically associated diseases. The diagnostic value is established of Proteinase 3 (PR3)-ANCA for Wegener's granulomatosis (WG) as well as Myeloperoxidase (MPO)-ANCA for microscopic polyangiitis (MPA). Within the last 20 years these antibodies were subject of intensive studies and a growing body of evidence arose for a distinct role of ANCA in the pathogenesis of the ANCA associated vasculitides WG and MPA. Our current concept of whether ANCA directly or indirectly contribute to vascular damage (ANCA-Cytokine-Sequence-Theory) was mainly developed from in vitro studies. It is plausible and it is supported by data from clinical investigations as well as animal models. Nevertheless our knowledge of the etiological and pathogenetic pathways remains incomplete.
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Wegener's granulomatosis (WG) is characterized by a predominance of the type 1 T-helper cell (Th1) response. We have studied monocytic cytokine expression in untreated patients and in patients who did not respond to prior methotrexate or trimethoprim-sulphamethoxazole therapy, i.e. patients with active disease. Intracytoplasmic IL-12 and TNF-alpha expression was significantly increased in WG compared with healthy controls. IL-8 expression was not increased. Two and 12 weeks of daily standard oral cyclophosphamide and corticosteroid (CYC + GC) treatment induced a stable remission of the disease. Elevated IL-12 and TNF-alpha expression of monocytes was normalized. The active metabolite of CYC was shown to down-regulate IL-12 mRNA in vitro. Monocytic cytokines, especially IL-12, may have a role in the early determination and skewing of the immunoregulatory response towards a Th1 profile. It appears that CYC + GC exerts its effect by normalizing the Th1-driving cytokine pattern, and CYC may maintain this mode of action. Normalization of the skewed cytokine pattern may be a prerequisite and an indicator of inducing a remission in WG.
OBJECTIVE: To evaluate the performance of 11 commercial enzyme-linked immunosorbent assay (ELISA) kits for the detection of antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) and myeloperoxidase (MPO) in patients with Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA). METHODS: Serum samples were taken from 92 patients with a histological and clinical diagnosis of WG (n=50) or MPA (n=42) and from 30 disease controls (systemic lupus erythematosus, n=15; rheumatoid arthritis, n=15) and 30 healthy controls. Each of the sera was tested for the presence of ANCA directed against PR3 and MPO using 11 commercially available direct ELISA kits, our in-house PR3- and MPO-ANCA capture ELISAs, and the indirect immunofluorescence technique (IFT). RESULTS: In tests for WG using PR3-ANCA, the commercial direct ELISA kits differed widely in their sensitivity (from 22 to 70%) and negative predictive value (NPV) (from 43 to 70%), but only moderately in their specificity (from 93 to 100%) and positive predictive value (PPV) (from 93 to 100%). The highest sensitivity (74%) and specificity (100%) for PR3-ANCA were obtained with the in-house capture ELISA. Similar differences and trends were noted for MPO-ANCA assays. Diagnostic sensitivity was more than 60% for four and at least 50% for six of the 11 ELISA kits. The PPV varied from 84 to 100% and the NPV from 58 to 70%. In tests for MPA, the MPO-ANCA ELISA kit designated F and the in-house capture ELISA were best (both had sensitivity 62% and specificity 100%). For both WG and MPA, maximum sensitivity for ANCA was obtained with IFT (80 and 70% respectively). CONCLUSION: Determination of PR3-ANCA and MPO-ANCA with the commercial direct ELISA kits achieved poor sensitivity for both WG and MPA. The in-house PR3 and MPO-ANCA capture ELISAs performed better than the commercial ELISAs, combining higher specificity with similar sensitivity. IFT remains the best method for ANCA detection in both diseases.
OBJECTIVE: To investigate cytokine production patterns of T cell lines (TCL) from patients with Churg-Strauss syndrome (CSS). METHODS: Short-term polyclonal TCL were generated from peripheral blood of patients with CSS or Wegener's granulomatosis (WG) and healthy controls (HC). TCL were established in the presence of interleukin-2 (IL-2) and phytohemagglutinin and were phenotypically characterized by flow cytometry. Th1/ Th2 cytokine production by stimulated TCL (72 hours) was analyzed by enzyme-linked immunosorbent assay. RESULTS: TCL that represented the progeny of in vivo-activated T cells from CSS patients displayed a heterogeneous immunophenotype, with a predominance of CD4+ T cells when compared with WG TCL, which were predominantly CD8+. All CSS TCL shared the ability to produce large amounts of interferon-gamma (IFNgamma), IL-4, and IL-13 compared with HC (P = 0.014 for all 3). Production of IL-4 and IL-13 was higher in CSS TCL than in WG TCL (P = 0.014 for both). IL-5 production was up-regulated in WG TCL compared with CSS TCL (P = 0.014). Compared with HC, WG TCL showed increased production of IFNgamma (P = 0.021), IL-5 (P = 0.043), and IL-13 (P = 0.021). CONCLUSION: Our results indicate that, while there is evidence for both a type 1 and a type 2 response in CSS, type 2 cytokine production pattern appears to predominate in this disease when compared with WG and HC.
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Amphipathic variable-region heavy chain 11-mer peptides from monoclonal human IgM antiproteinase-3 antibodies were studied for peripheral blood lymphocyte stimulation in 21 patients with Wegener's granulomatosis (WG) or microscopic polyangiitis (MPA), connective tissue disease controls and normal control subjects. Positive T-cell activation was observed in most experiments with WG patients' lymphocytes using amphipathic VH-region peptides from four different human monoclonal anti-PR3 antibodies. Control peptides of the same length but without amphipathic characteristics along with other amphipathic peptides not derived from monoclonal anti-PR3 sequence were employed as controls. No significant lymphocyte stimulation was observed with normal controls, but positive stimulation with amphipathic VH peptides was also recorded in other connective tissue disease controls mainly patients with rheumatoid arthritis. Amphipathic peptides not derived from anti-PR3 sequence did not stimulate WG lymphocytes. Our findings indicate that lymphocyte reactivity as an element of cell-mediated immunity may be activated by amphipathic VH-region amino acid sequences of autoantibodies which are themselves associated with diseases such as WG.
CTLA-4 (CD152) is a surface molecule of activated T cells with sequence homology to CD28. Both molecules bind to the same ligands, B7.1 (CD80) and B7.2 (CD86) but have antagonistic functions. While CD28 is an important costimulator, CTLA-4 has an essential inhibitory function in maintaining the homeostasis of the immune system. Furthermore, CTLA-4 has a role in inducing a Th1 response and suppressing Th2 cytokines, an effect which is antagonized by CD28. Many autoimmune diseases are characterized by an overwhelming production of Th1 cytokines. Recently, the predominance of the Th1 cytokine pattern has been directly observed in the granulomatous inflammation of patients with Wegener's granulomatosis. The balance between CD28 and CTLA-4 expression by T lymphocytes could be a factor in the pathogenesis of autoimmune diseases. Down regulation of CD28 predominantly on CD8+ T cells has been described in Wegner's granulomatosis; however, analysis of CTLA-4 is complicated by its low expression levels. Here we have used potent signal enhancement to study CTLA-4 on PBMC in patients with Wegener's granulomatosis (n = 25) in comparison with healthy controls (n = 19). Expression levels of CTLA-4 were significantly increased selectively on CD4+ and possibly also on CD4-/CD8- T cells in Wegener's granulomatosis. High CTLA-4 expression by T lymphocytes was associated with more severe disease. In contrast, after stimulation with the mitogen PHA, CTLA-4 levels were strongly increased on T cells from controls but in T cells from Wegener's granulomatosis patients this response was severely impaired. Interestingly, while CTLA-4 was seen exclusively on T cells in control individuals, about half of the Wegener's patients showed CTLA-4 expression by a fraction of peripheral B lymphocytes. CTLA-4 positive B cells in the periphery were associated with less acute disease.
OBJECTIVES: To evaluate the prevalence and association of antineutrophil cytoplasmic antibodies (ANCA) and their subtypes [proteinase 3 (PR3)-ANCA, myeloperoxidase (MPO)-ANCA] with distinct clinical features in various clinicopathological syndromes. METHODS: All consecutive ANCA-positive patients seen at the combined unit for rheumatology for Bad Bramstedt and the University of Lübeck between 1989 and 1999 were analysed. ANCA were detected by an immunofluorescence technique and ANCA subspecificities were determined by ELISA. Clinical features at presentation and diagnoses were recorded according to standardized procedures. RESULTS: Among 4620 patients tested, 333 were cytoplasmic ANCA-positive and 291 were perinuclear ANCA-positive. cANCA/PR3-ANCA were strongly associated with Wegener's granulomatosis (WG), whereas pANCA/MPO-ANCA were associated with a diverse disease spectrum. Further investigation of PR3-ANCA-positive (n=80) and MPO-ANCA-positive patients (n=40) revealed a greater extent of disease [disease extent index (DEI); median 8 vs 5, P<0.01] and more frequent involvement of the upper/lower respiratory tract and the eyes in PR3-ANCA-positive than in MPO-ANCA-positive patients. Fewer than 5% of WG patients were MPO-ANCA-positive. Compared with matched PR3-ANCA-positive WG patients, the MPO-ANCA-positive WG patients had a lower DEI (median 5 vs 8) and had a lower frequency of peripheral neuropathy. CONCLUSIONS: ANCA testing is useful due to its high sensitivity and specificity, especially for cANCA/PR3-ANCA in WG. We found a divergence in the disease spectrum between PR3- and MPO-ANCA-positive patients, characterized by higher DEI and extrarenal manifestations in the PR3-ANCA group. MPO-ANCA was rarely found in WG and was associated with less organ involvement.
OBJECTIVE: To study immunological markers and compare these markers with standard measures for the clinical and immunological follow up of vasculitis activity in hepatitis C virus (HCV) associated cryoglobulinaemic vasculitis (CV). METHODS: Serial serum samples from eight patients with newly diagnosed HCV associated CV were followed during interferon alpha treatment induced remission of the CV. Vasculitis activity and disease extent were evaluated with the Birmingham vasculitis activity score (BVAS) and disease extent index (DEI). Cryoglobulinaemia, complement levels (C3c, C4, and CH50), rheumatoid factor (RF), autoantibodies such as antinuclear antibodies, soluble interleukin 2 receptor (sIL2r), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble CD30 (sCD30) were determined. RESULTS: All patients achieved either complete or partial remission of their CV during interferon alpha treatment. There was a significant reduction in vasculitis activity and disease extent (BVAS, DEI), cryoglobulinaemia, RF, sIL2r, sICAM-1, and sCD30. Complement C3c levels increased significantly during this period. Erythrocyte sedimentation rate and levels of complement C4 and CH50 did not change significantly. Both clinical measures (BVAS and DEI) correlated significantly only with C3c and sCD30. CONCLUSIONS: Although this study was of only a small group of patients, it shows that BVAS and DEI as clinical measures and C3c and sCD30 as immunological markers may be useful in the follow up of disease activity of HCV associated CV. The data indicate that activity of the humoral (cryoglobulinaemia, RF, autoantibodies) and cellular (sIL2r, sICAM-1, sCD30) immune response and endothelial damage (sICAM-1) are found in HCV associated CV.
BACKGROUND: Lack of CD28 expression on peripheral blood CD4+ and CD8+ T cells has been reported in patients with Wegener's granulomatosis (WG), suggesting a pathogenetic role of CD28- T cells in WG. METHODS: Ten patients with WG and six with sarcoidosis (disease control) were analysed. Fluorescence activated cell sorter (FACS) analysis was used to detect CD28 expression on T cells from peripheral venous blood and from bronchoalveolar lavage (BAL) fluid. T cells in biopsy specimens from granulomatous lesions of the upper respiratory tract were analysed for CD28 expression by double immunofluorescence staining. RESULTS: A significantly higher fraction of CD28- T cells was found in the CD4+ and CD8+ T cell compartment in BAL fluid (65.6 (5.4)% and 76.3 (4.1)%, respectively) than in blood (13.4 (6.2)% and 42.9 (6.2)%; p<0.001) in patients with WG but not in those with acute sarcoidosis (6.7 (2.2)% and 53.4 (7.3)% in BAL fluid v 4.1 (2.5)% and 52.0 (9.4)% in blood). The total number of CD4+/CD28- T cells but not of CD8+/CD28- T cells was also significantly higher in BAL fluid than in blood in patients with WG (p<0.05). Patients with WG had a significantly higher fraction of CD28- T cells in the CD4+ and CD8+ T cell compartment in BAL fluid than patients with acute sarcoidosis (65.6 (5.4)% v 6.7 (2.2)%; p<0.001; and 76.3 (4.1)% v 53.4 (7.3)%; p<0.05). The total number of CD4+/CD28- and CD8+/CD28- T cells was also significantly higher in patients with WG than in those with sarcoidosis (p<0.01). An abundance of CD28- T cells was found in granulomatous lesions by double immunofluorescence staining in patients with WG. CONCLUSIONS: Our data indicate enrichment of CD28- T cells in BAL fluid and suggest recruitment of CD28- T cells into granulomatous lesions in WG. Further analysis of the phenotype and function of T cell subsets in WG is needed to better understand leucocyte homing in WG and to find new therapeutic targets.
Anti-neutrophil cytoplasmic antibodies (ANCA) targeting proteinase 3 (PR3) possess a high sensitivity and specificity for Wegener's granulomatosis. Due to their capacity of directly activating neutrophils, a pathogenetic role for these autoantibodies has been proposed. We investigated the impact of subthreshold concentrations of monoclonal anti-PR3 antibodies (anti-PR3; 0.1 microg/mL) on neutrophil activation elicited by a secondary agent. Preincubation with anti-PR3 resulted in a massive amplification of N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced leukotriene (LT) generation, with a marked increase in the liberation of LTB4, LTA4, and 5-hydroxyeicosatetraenoic acid (5-HETE). This priming commenced within 2.5 min, with a maximum after 5-7.5 min. Moreover, anti-PR3 pretreatment markedly enhanced PMN movement toward fMLP. The priming effect of anti-PR3 toward fMLP challenge was reproduced by c-ANCA, but not by F(ab)2 fragments of the antibodies and isotype-matched control IgG. Generation of superoxide anion and release of elastase were suppressed in anti-PR3-pretreated neutrophils undergoing fMLP challenge. In contrast, neutrophil activation by platelet-activating factor (PAF) or the calcium ionophore A23187 remained unaffected. We conclude that subthreshold concentrations of anti-PR3 antibodies selectively modify neutrophil responses to fMLP, with enhancement of leukotriene generation and chemotaxis, but suppression of respiratory burst and degranulation. Such priming might contribute to localized neutrophil accumulation together with blunted host defense in Wegener's granulomatosis.
The immune response in Wegener's granulomatosis (WG) has been characterized as a predominant, potentially pathogenic Th1-like reaction by blood T cells and T-cell clones from diseased tissues. To elucidate further the immunopathogenic mechanisms, this study analysed the phenotypes of inflammatory infiltrates in frozen nasal biopsies with involvement of the upper respiratory tract only (localized or 'initial phase' WG) and with multi-organ involvement, including systemic vasculitis (generalized WG). The expression and production of Th1 and Th2 cytokines were examined in tissue specimens and peripheral blood mononuclear cells (PBMCs) of localized and generalized WG. The number of CD3+ T cells in inflammatory infiltrates ranged from 50 to 70%, together with approximately 30% CD14+ monocytes/macrophages. An average of 40% of T cells expressed CD26 in nasal biopsies of localized WG, compared with about 16% in specimens of generalized WG. In parallel, a higher number of interferon-gamma (IFN-gamma)-positive cells were detected in nasal tissue of localized than in generalized WG. PBMCs from localized WG similarly exhibited higher spontaneous IFN-gamma production in contrast to generalized WG (207 vs. 3 pg/ml, p<0.05). Interleukin-4 (IL-4) mRNA was found in higher amounts in generalized than in localized WG. IL-4 production was negligible in both disease and controls. In addition, both IL-10 mRNA and IL-10 protein levels of activated PBMCs from localized WG were elevated when compared with generalized disease (574 vs. 154 pg/ml, p<0.05) or healthy controls (574 vs. 246 pg/ml, p<0.05). It is conluded that in nasal tissues, mainly CD4+/CD26+ T cells as well as IFN-gamma-positive cells may support a polarized Th1-like immune response. Furthermore, the data suggest that this in situ immune response is already initiated and established in localized WG, accompanied by increased peripheral IFN-gamma and IL-10 production.