Elena Csernok

Peripheral Blood and Granuloma CD4+CD28− T Cells Are a Major Source of Interferon-γ and Tumor Necrosis Factor-α in Wegener’s Granulomatosis

To elucidate whether the fraction of CD28− T cells within the CD4+ T-cell population is a major source of Th1-like and proinflammatory cytokine production driving Wegener’s granulomatosis (WG) granuloma formation, we analyzed the phenotype and functional characteristics of peripheral blood CD4+CD28− T cells and of T cells in granulomatous lesions of 12 patients with active WG. Surface markers and intracytoplasmic cytokine and perforin expression were assessed by flow cytometry. Cytokine secretion was measured by enzyme-linked immunosorbent assay. Immunohistological studies demonstrated interferon-γ and tumor necrosis factor-α cytokine positivity attributable to CD4+CD28− T cells in granulomatous lesions. Peripheral blood CD4+CD28− T cells expressed CD57, also found on natural killer cells, and intracytoplasmic perforin. They were generally CD25 (interleukin-2 receptor)-negative. CD18 (adhesion molecule β2-integrin) was strongly up-regulated on CD4+CD28− T cells, whereas only a minority of CD4+CD28+ T cells expressed CD18. CD4+CD28− T cells appeared as a major source of interferon-γ and tumor necrosis factor-α. In contrast, CD4+CD28+ T cells were able to produce and secrete a wider variety of cytokines including interleukin-2. One-quarter of CD4+CD28+ T cells expressed the activation marker CD25, but they lacked perforin. Thus, CD4+CD28− T cells appeared more differentiated than CD4+CD28+ T cells. They displayed Th1-like cytokine production and features suggestive of the capability of CD4+ T-cell-mediated cytotoxicity. CD4+CD28− T cells may be recruited into granulomatous lesions from the blood via CD18 interaction, and may subsequently promote monocyte accumulation and granuloma formation through their cytokine secretion in WG.

Prospective long-term follow-up of patients with localised Wegener's granulomatosis: does it occur as persistent disease stage?

Objective To identify patients with localised Wegeners granulomatosis (locWG) to assess whether it occurs as a long-term disease stage or phenotype and to characterise its outcome. Methods Patients in a ‘localised stage’ with histological criteria compatible with WG and a follow-up period of ≥1 year were included. They were prospectively followed at the Vasculitis Center Schleswig-Holstein from 1989 to 2009 and the clinical manifestations, antineutrophil cytoplasmic autoantibodies (ANCA) status and damage were evaluated. Immunosuppression was adapted to disease activity and severity in a step-up regimen. Results Of 1024 patients with suspected WG, 99 were clinically diagnosed with locWG and 50 fulfilled the inclusion criteria (72% women, median age 43 years, 46% ANCA-positive). The median follow-up was 48 months. All achieved a response to treatment, 34% achieved complete remission, 1–4 relapses occurred in 46%, 5 (10%) had generalised disease (median 6 years after onset). ANCA status was not associated with relapse (p=0.98), transition to generalised disease (p=0.51) or refractory manifestations (p=0.60). 47% required cyclophosphamide for localised manifestations, 36% of them for pulmonary masses and 24% for orbital masses. 66% developed organ damage, mostly due to bony destruction or space obturation (28% saddle nose, 24% septal perforation, 10% orbital wall destruction). There were two deaths that were not related to WG. Conclusion There is evidence that locWG is a long-term disease stage or phenotype (5% of all patients with WG), 46% of whom are ANCA-positive. LocWG is characterised by destructive and/or space-consuming lesions associated with high relapse rates (46%) and local damage.

New genomic region for Wegener's granulomatosis as revealed by an extended association screen with 202 apoptosis-related genes.

Wegener’s granulomatosis (WG) is a systemic disease with complex genetic background. It is characterized by necrotizing granulomatous inflammation of the upper and lower respiratory tract, glomerulonephritis, vasculitis and the presence of antineutrophil cytoplasmatic autoantibodies (C-ANCAs) in sera of patients. Here, we report on an extended association screen (EAS) with 202 microsatellite markers, representing apoptosis-related genes and further genes down-regulated in apoptotic neutrophils, using pooled DNA of 150 Northern German patients suffering from WG and 100 healthy Northern German controls. Six microsatellite allele patterns were found significantly associated with WG, three of which could be confirmed by individual genotyping. One marker remained significantly associated after multiple corrections. This marker representing the retinoid X receptor ß gene (RXRB, P=7.60×10−6, distance to gene: ~5.3xa0kb) is localised in the major histocompatibility complex (MHC) region between the HLA-DPB1 and DAXX genes. HLA-DPB1 typing and fine mapping of the region with additional microsatellites and single-nucleotide polymorphisms (SNPs) revealed a strong association of WG with the significantly over-represented DPB1*0401 (P=1.51×10−10, OR=3.91) allele compared with the control cohort. In addition, an extended haplotype DPB1*0401/RXRB03 was identified showing an even stronger association with WG (P=7.13×10−17, OR=6.41). These results represent the strongest association of a genomic region with WG, suggesting a major genetic contribution in the aetiology of the disease. Thus, our data demonstrate that EAS may be a valuable alternative approach for determining genetic predisposition factors in multifactorial diseases.

CD28 negative T cells are enriched in granulomatous lesions of the respiratory tract in Wegener's granulomatosis

BACKGROUND Lack of CD28 expression on peripheral blood CD4+ and CD8+ T cells has been reported in patients with Wegeners 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 v4.1 (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.

Antineutrophil Cytoplasmic Autoantibody-Associated Diseases: A Rheumatologist's Perspective

Autoantibodies against neutrophil cytoplasmic antigens (ANCA) produce two major immunofluorescence (IF) patterns on ethanol-fixed granulocytes: the classical (centrally accentuated) C-ANCA, associated with Wegeners granulomatosis (WG), and P-ANCA (perinuclear), which mainly occur in renal vasculitis. Rheumatic manifestations are an important clinical finding in systemic vasculitis, often preceding a fulminant course and sometimes imitating various rheumatic disorders. We analyzed the incidence of ANCA in rheumatic patients and looked for the frequency of rheumatic symptoms in systemic vasculitis. In WG (n = 186), we found rheumatic symptoms in 55% (myalgia, 45%; arthritis, 21%); in 90%, rheumatic complaints were associated with active vasculitis. In 730 patients with various rheumatic conditions (eg, 268 rheumatoid arthritis, 130 systemic lupus erythematosis [SLE], 32 sharp-S, 50 ankylosing spondylitis, 43 systemic sclerosis) no C-ANCA were found. On the contrary, the P-ANCA pattern was seen in seven of 62 giant cell arteritis, five of 27 Feltys/Stills syndrome, and four of 130 SLE patients in addition to renal vasculitis (21/74). We demonstrated that 95% of C-ANCA-positive sera react with proteinase 3 (PR3 or myeloblastin). Using monoclonal antibodies, we showed that PR3 is expressed on the plasma membrane of neutrophil granulocytes and monocytes; thus, PR3 autoantigens are accessible for circulating antibodies. The detection of ANCA in sera from vasculitis and other rheumatic diseases is of immunodiagnostic value and provides new insight in the pathogenesis of systemic vasculitides.

ANCA in Systemic Vasculitides, Collagen Vascular Diseases, Rheumatic Disorders and Inflammatory Bowel Diseases

It was the aim of this study to reevaluate the diagnostic significance and clinical implication of ANCA after testing sera from 13,606 patients for the presence of ANCA. Our data confirm the high specificity (97%) and sensitivity (80%) of cANCA for Wegeners granulomatosis. pANCA were found in renal vasculitides (60%), collagen vascular diseases (SLE 20%, Sjögrens syndrome 26%, polymyositis 16%) and rheumatic disorders (Feltys syndrome 50%, rheumatoid arthritis 20%). A third fluorescence pattern in sera of patients with inflammatory bowel disease (ulcerative colitis 28/72, Crohns disease 6/84), here called xANCA, was seen. Target antigens of granule proteins from PMN and monocytes (proteinase 3, myeloperoxidase, elastase, cathepsin G, lactoferrin, lysozyme) were identified.

Autoantibody Detection Using Indirect Immunofluorescence on HEp-2 Cells

The detection of autoantibodies is an important element in the diagnosis and monitoring of disease progression in patients with autoimmune diseases. In laboratory diagnostic tests for connective tissue and autoimmune liver diseases, indirect immunofluorescence on HEp‐2 cells plays a central role in a multistage diagnostic process. Despite the high quality of diagnostics, findings at different laboratories can differ considerably due to a lack of standardization, as well as subjective factors.

Current and emerging techniques for ANCA detection in vasculitis

Detection of antineutrophil cytoplasmic antibodies (ANCAs) is a well-established diagnostic test used to evaluate suspected necrotizing vasculitis of small blood vessels. Conditions associated with these antibodies, collectively referred to as ANCA-associated vasculitides, include granulomatosis with polyangiitis (formerly known as Wegener granulomatosis), microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis (formerly known as Churg–Strauss syndrome). The diagnostic utility of ANCA testing depends on the type of assay performed and on the clinical setting. Most laboratories worldwide use standard indirect immunofluorescence tests (IFT) to screen for ANCA and then confirm positive IFT results with antigen-specific tests for proteinase 3 (PR3) and myeloperoxidase (MPO). Developments such as automated image analysis of immunofluorescence patterns, so-called third-generation PR3-ANCA and MPO-ANCA ELISA, and multiplex technology have improved the detection of ANCAs. However, challenges in routine clinical practice remain, including methodological aspects of IFT performance, the diverse antigen-specific assays available, the diagnostic value of testing in clinical settings and the prognostic value of serial ANCA monitoring in the prediction of disease relapse. This Review summarizes the available data on ANCA testing, discusses the usefulness of the various ANCA assays and advises on the clinical indications for the use of ANCA testing.

Clinical and immunological features of drug-induced and infection-induced proteinase 3-antineutrophil cytoplasmic antibodies and myeloperoxidase-antineutrophil cytoplasmic antibodies and vasculitis.

Purpose of reviewDrugs and infections may induce antineutrophil cytoplasmic antibodies (ANCA) and vasculitic manifestations mimicking ANCA-associated vasculitides (AAV) and mechanisms relevant in their pathogenesis. This review summarizes the most recent findings in this field. Recent findingsDrug-induced and infection-induced proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA may be associated with a vasculitis clinically resembling AAV. Mechanisms relevant for the break of tolerance and induction of ANCA (e.g. danger signals, superantigens, neutrophil extracellular traps, protease-activated receptor-2, IL-17 cells) may be shared to some extent between drug-induced and infection-induced ANCA-positive vasculitis and AAV, especially with regard to the potential role of infection in Wegeners granulomatosis. Differences in immunopathology, clinical presentation, and functional aspects of ANCA help to distinguish drug-induced and infection-induced ANCA-positive vasculitis from AAV, and present new avenues for future research in this field. SummaryMedications and infections, which induce PR3-ANCA and MPO-ANCA, have to be considered in the differential diagnosis of primary AAV. Moreover, there is clinical and experimental evidence for an association between certain drugs and infections with ANCA-production. Analysis of ANCA-induction in such conditions also sheds new light on our understanding of immune mechanisms relevant in the break of tolerance and ANCA-production in AAV.

Differences in CCR5 expression on peripheral blood CD4+CD28− T-cells and in granulomatous lesions between localized and generalized Wegener’s granulomatosis

Wegeners granulomatosis (WG) is an autoimmune disease characterized by granulomatous lesions and a necrotizing vasculitis. Th1-type-cells lacking CD28 are expanded independent of age and immunosuppressive therapy in WG. To address their migratory properties of CD4(+)CD28(-) T-cells we studied the expression of the inducible inflammatory Th1-type chemokine receptor CCR5 in localized WG and generalized WG. Expansion of CD4(+)CD28(-) T-cells was more prominent in generalized WG compared to localized WG. In localized WG a larger fraction of CD4(+)CD28(-) T-cells displayed CCR5 expression compared to generalized WG. CCR5 expression was also higher in granulomatous lesions in localized WG. Higher levels of CCR5 expression on CD4(+)CD28(-) T-cells in localized WG may favor stronger CCR5-mediated recruitment of this T-cell subset into granulomatous lesions in localized WG. Expansion of Th-1-type CD4(+)CD28(-)CCR5(+) effector memory T-cells might contribute to disease progression and autoreactivity, either directly, by maintaining the inflammatory response, or as a result of bystander activation.