Analysis of the B cell receptor repertoire in six immune-mediated diseases.

B cells are important in the pathogenesis of many, and perhaps all, immune-mediated diseases. Each B cell expresses a single B cell receptor (BCR)1, and the diverse range of BCRs expressed by the total B cell population of an individual is termed the 'BCR repertoire'. Our understanding of the BCR repertoire in the context of immune-mediated diseases is incomplete, and defining this could provide new insights into pathogenesis and therapy. Here, we compared the BCR repertoire in systemic lupus erythematosus, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, Crohn's disease, Behçet's disease, eosinophilic granulomatosis with polyangiitis, and immunoglobulin A (IgA) vasculitis by analysing BCR clonality, use of immunoglobulin heavy-chain variable region (IGHV) genes and-in particular-isotype use. An increase in clonality in systemic lupus erythematosus and Crohn's disease that was dominated by the IgA isotype, together with skewed use of the IGHV genes in these and other diseases, suggested a microbial contribution to pathogenesis. Different immunosuppressive treatments had specific and distinct effects on the repertoire; B cells that persisted after treatment with rituximab were predominately isotype-switched and clonally expanded, whereas the inverse was true for B cells that persisted after treatment with mycophenolate mofetil. Our comparative analysis of the BCR repertoire in immune-mediated disease reveals a complex B cell architecture, providing a platform for understanding pathological mechanisms and designing treatment strategies.

The alternative complement pathway in ANCA-associated vasculitis: further evidence and a meta-analysis.

We compared the common pathway components C3a, C5a and membrane attack complex (MAC), also known as C5b-9, and the alternative pathway components factor B and properdin in patients with ANCA-associated vasculitis (AAV) and healthy controls, and conducted a meta-analysis of the available clinical evidence for the role of complement activation in the pathogenesis of AAV. Complement components were evaluated in 59 patients with newly diagnosed or relapsing granulomatosis with polyangiitis or microscopic polyangiitis and 36 healthy volunteers. In 28 patients, testing was repeated in remission. Next, we performed a meta-analysis by searching databases to identify studies comparing complement levels in AAV patients and controls. A random-effects model was used for statistical analyses. The median concentrations of MAC, C5a, C3a and factor B were higher in active AAV patients (P < 0·001). Achievement of remission was associated with reductions in C3a (P = 0·005), C5a (P = 0·035) and factor B levels (P = 0·045), whereas MAC and properdin levels did not change. In active AAV, there were no effects of ANCA specificity, disease phenotype, previous immunosuppression or disease severity on complement levels. A total of 1122 articles were screened, and five studies, including this report, were entered into the meta-analysis. Plasma MAC, C5a and factor B in patients with active AAV were increased compared to patients in remission (excluding factor B) and controls. Changes in C3a were of borderline significance. Our findings and the results of the meta-analysis support activation of the complement system predominantly via the alternative pathway in AAV patients.

Rituximab for the treatment of eosinophilic granulomatosis with polyangiitis (Churg-Strauss).

BACKGROUND: Conventional treatment of eosinophilic granulomatosis with polyangiitis (EGPA) (Churg-Strauss) with glucocorticoids, with or without additional immunosuppressive drugs, is limited by partial efficacy, frequent toxicity and a high relapse rate. Rituximab is a licensed treatment for granulomatosis with polyangiitis and microscopic polyangiitis and is of potential benefit to patients with EGPA. METHODS: Patients with EGPA who received rituximab as single or repeated courses were identified from four vasculitis centres. Standardised data collection was performed, including disease activity status and adverse events, at the time of initial treatment and after 6 and 12 months. Remission was defined as a Birmingham Vasculitis Activity Score (BVAS) of 0 and partial response as a ≥50% reduction in BVAS compared with baseline. RESULTS: 41 patients (21 women) with EGPA treated with rituximab between 2003 and 2013 were identified. 15 (37%) had refractory, 21 (51%) relapsing and 5 (12%) new onset disease. 19 received a single course and 22 received repeat-dose rituximab to prevent relapse. By 6 months, 83% improved with remission in 34% and partial response in 49%, and by 12 months 49% were in remission and 39% had a partial response. Prednisolone doses decreased in all patients by 6 and 12 months. Antineutrophil cytoplasmic antibody positivity at baseline was associated with a higher remission rate at 12 months. Adverse events included 15 infections (6 were severe). CONCLUSIONS: The treatment of EGPA with rituximab resulted in high rates of improvement and reduced requirement of prednisolone. Rituximab may be considered for the treatment of EGPA.

Rituximab for ANCA-associated vasculitis in the setting of severe infection.

OBJECTIVES: The combination of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) and severe infection presents a challenge because current therapies with high-dose glucocorticoids and cyclophosphamide (CYC) are immunosuppressive and increase the risk of infection. Thus, coincident infection delays and complicates the introduction of treatment. Rituximab (RTX) is an alternative to CYC in AAV and may be preferable in the setting of severe infection. METHOD: From 2005 to July 2011, 100 patients with AAV were treated with RTX at our institution and those who received RTX instead of CYC because of concomitant infection were studied. RESULTS: Eight patients were identified. The mean follow-up was 12 months (range 6-30 months). All patients achieved remission by 6 months that was sustained to the end of follow-up. There were no deaths or further severe infections. CONCLUSIONS: RTX can be considered for patients with generalized AAV and concomitant severe infection.

Long-term outcome of severe alveolar haemorrhage in ANCA-associated vasculitis: a retrospective cohort study.

OBJECTIVES: Alveolar haemorrhage (AH) is a major cause of early death in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). There is a paucity of information regarding the outcomes of AAV patients presenting with severe AH. METHOD: A retrospective cohort study. Patients with severe AH were identified from a case review of 824 AAV patients. Demography, presenting features, treatment, and outcomes are described. RESULTS: Fifty-three patients (33 males, 20 females; median age 59 years) with severe AH were identified: 37 (69.8%) with granulomatosis with polyangiitis (Wegener's) and 16 with microscopic polyangiitis [36 proteinase 3 (PR3)-ANCA positive and 17 myeloperoxidase (MPO)-ANCA positive]. AH was the first disease manifestation in 46 (86.8%) patients. Assisted ventilation was required in 36 (67.9%), renal involvement was present in 52 (98.1%), and 28 (52.8%) required dialysis. Forty (75.5%) received plasma exchange. At 3 months, 44/53 (83.0%) were alive. The mean follow-up was 49 months when 31 (58.5%) were alive and 24 (45.3%) dialysis independent. Mortality was higher in those requiring dialysis at entry (57.1% vs. 24%, p = 0.02) and in patients aged > 65 years (71.4% vs. 30.8%, p = 0.01), and tended to be higher in those requiring intubation (54.5% vs. 32.2%, p = 0.1). CONCLUSIONS: Severe AH was more commonly associated with PR3-ANCA (vs. MPO-ANCA) and strongly correlated with renal vasculitis. Current treatment of severe AH leads to remission but long-term mortality remains high. Concurrent renal failure and older age were associated with higher mortality.

Changes in proteinase 3 anti-neutrophil cytoplasm autoantibody levels in early systemic granulomatosis with polyangiitis (Wegener's) may reflect treatment rather than disease activity.

OBJECTIVES: To investigate the nature of the relationship between proteinase 3 anti-neutrophil cytoplasm autoantibody (PR3-ANCA) and relapse in patients with early systemic granulomatosis with polyangiitis (Wegener's) (GPA). METHODS: Clinical data from 16 relapsing and 12 non-relapsing patients with early systemic GPA from a randomised clinical trial were correlated to monthly PR3-ANCA values over 18 months. Each sample was examined using 9 different enzyme-linked immunosorbent assays (ELISAs) to ensure reliability of ANCA results. PR3-ANCA peaks were identified by the highest sum of logarithmic transformation values from all assays in samples after remission. RESULTS: A PR3-ANCA peak was identified in all relapsing and non-relapsing patients and coincided with relapse in all 14 evaluable relapsing patients. The monthly increment before the peak, however, was similar in relapsing and non-relapsing patients in all assays. Increments from remission to peak were higher in relapsing patients in 2/9 assays. PR3-ANCA values at entry and peak PR3-ANCA values were higher in relapsing patients in 3/9 and 2/9 assays, respectively. However, large overlaps of PR3-ANCA values prevented a distinction between relapsing and non-relapsing patients. The median time to reach peak values was 14 months in relapsing and 12 months in non-relapsing patients with scheduled termination of treatment at 12 months. CONCLUSIONS: The predictive value for relapses of PR3-ANCA determinations confirm and extend previous reports. Although all relapses were related to PR3-ANCA increases, reduction or withdrawal of immunosuppression without relapse was also related to increases and may explain the lack of predictive value of sequential PR3-ANCA determinations.

EULAR recommendations for vaccination in adult patients with autoimmune inflammatory rheumatic diseases.

OBJECTIVES: To develop evidence-based European League Against Rheumatism (EULAR) recommendations for vaccination in patients with autoimmune inflammatory rheumatic diseases (AIIRD). METHODS: A EULAR task force was composed of experts representing 11 European countries, consisting of eight rheumatologists, four clinical immunologists, one rheumatologist/clinical immunologist, one infectious disease physician, one nephrologist, one paediatrician/rheumatologist and one clinical epidemiologist. Key questions were formulated and the eligible spectrum of AIIRD, immunosuppressive drugs and vaccines were defined in order to perform a systematic literature review. A search was made of Medline from 1966 to October 2009 as well as abstracts from the EULAR meetings of 2008 and 2009 and the American College of Rheumatology (ACR) meetings of 2007 and 2008. Evidence was graded in categories I-IV, the strength of recommendations was graded in categories A-D and Delphi voting was applied to determine the level of agreement between the experts of the task force. RESULTS: Eight key questions and 13 recommendations addressing vaccination in patients with AIIRD were formulated. The strength of each recommendation was determined. Delphi voting revealed a very high level of agreement with the recommendations among the experts of the task force. Finally, a research agenda was proposed. CONCLUSION: Recommendations for vaccination in patients with AIIRD based on the currently available evidence and expert opinion were formulated. More research is needed, particularly regarding the incidence of vaccine-preventable infectious diseases and the safety of vaccination in patients with AIIRD.

Deoxyspergualin in relapsing and refractory Wegener's granulomatosis.

OBJECTIVES: Conventional therapy of Wegener's granulomatosis with cyclophosphamide and corticosteroids is limited by incomplete remissions and a high relapse rate. The efficacy and safety of an alternative immunosuppressive drug, deoxyspergualin, was evaluated in patients with relapsing or refractory disease. METHODS: A prospective, international, multicentre, single-limb, open-label study. Entry required active Wegener's granulomatosis with a Birmingham vasculitis activity score (BVAS) > or =4 and previous therapy with cyclophosphamide or methotrexate. Immunosuppressive drugs were withdrawn at entry and prednisolone doses adjusted according to clinical status. Deoxyspergualin, 0.5 mg/kg per day, was self-administered by subcutaneous injection in six cycles of 21 days with a 7-day washout between cycles. Cycles were stopped early for white blood count less than 4000 cells/mm(3). The primary endpoint was complete remission (BVAS 0 for at least 2 months) or partial remission (BVAS <50% of entry score). After the sixth cycle azathioprine was commenced and follow-up continued for 6 months. RESULTS: 42/44 patients (95%) achieved at least partial remission and 20/44 (45%) achieved complete remission. BVAS fell from 12 (4-25), median (range) at baseline to 2 (0-14) at the end of the study (p<0.001). Prednisolone doses were reduced from 20 to 8 mg/day (p<0.001). Relapses occurred in 18 (43%) patients after a median of 170 (44-316) days after achieving remission. Severe or life-threatening (> or = grade 3) treatment-related adverse events occurred in 24 (53%) patients mostly due to leucopaenias. CONCLUSIONS: Deoxyspergualin achieved a high rate of disease remission and permitted prednisolone reduction in refractory or relapsing Wegener's granulomatosis. Adverse events were common but rarely led to treatment discontinuation.

Comparison of disease activity measures for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis.

AIM: Currently, several different instruments are used to measure disease activity and extent in clinical trials of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, leading to division among investigative groups and difficulty comparing study results. An exercise comparing six different vasculitis instruments was performed. METHODS: A total of 10 experienced vasculitis investigators from 5 countries scored 20 cases in the literature of Wegener granulomatosis or microscopic polyangiitis using 6 disease assessment tools: the Birmingham Vasculitis Activity Score (BVAS), The BVAS for Wegener granulomatosis (BVAS/WG), BVAS 2003, a Physician Global Assessment (PGA), the Disease Extent Index (DEI) and the Five Factor Score (FFS). Five cases were rescored by all raters. RESULTS: Reliability of the measures was extremely high (intraclass correlations for the six measures all = 0.98). Within each instrument, there were no significant differences or outliers among the scores from the 10 investigators. Test/retest reliability was high for each measure: range = 0.77 to 0.95. The scores of the five acute activity measures correlated extremely well with one another. CONCLUSIONS: Currently available tools for measuring disease extent and activity in ANCA-associated vasculitis are highly correlated and reliable. These results provide investigators with confidence to compare different clinical trial data and helps form common ground as international research groups develop new, improved and universally accepted vasculitis disease assessment instruments.

A comparative study of the diagnostic accuracy of ELISA systems for the detection of anti-neutrophil cytoplasm antibodies available in Japan and Europe.

OBJECTIVES: Primary systemic vasculitis associated with anti-neutrophil cytoplasm antibodies (ANCA) differs in its frequency and clinical expression between Japan and Europe. We sought to ascertain whether such differences arise from the performance of enzyme-linked immunosorbent assays (ELISAs) for ANCA. METHODS: Plasma samples from 64 consecutive Japanese patients with a clinical and histological diagnosis of primary systemic vasculitis including microscopic polyangiitis (MPA; n=52), Churg-Strauss syndrome (CSS; n=1), and Wegener's granulomatosis (WG; n=11), or those from disease controls with non-vasculitic glomerulonephritis (n=54) and healthy controls (n=55) were tested for the presence of myeloperoxidase (MPO) by ELISAs available in Japan (Nipro and MBL) and compared with those in Europe (Wieslab). The sensitivity and specificity were calculated for each ELISA, and its diagnostic performance was assessed by receiver operating characteristic curve analysis. RESULTS: The sensitivity and specificity of either MPO-ANCA assays for a diagnosis of MPA were 90.4% and 98.2% (Nipro), 88.2% and 96.3% (MBL), and 86.5% and 99.1% (Wieslab). The overall diagnostic performance, assessed as the area under curve of the MPO-ANCA ELISAs for MPA were 0.946+/-0.022 (Nipro), 0.970+/-0.017 (MBL), and 0.971+/-0.017 (Wieslab), while that of PR3-ANCA ELISAs for WG were 0.986+/-0.025 (Nipro), 0.993+/-0.017 (MBL), and 0.916+/-0.059 (Wieslab). CONCLUSIONS: The MPO-ANCA ELISAs commercially available in Japan exhibited high sensitivity and specificity for the diagnosis of ANCA-associated vasculitides and provided similar diagnostic value to those in Europe. These results facilitate further international comparison of ANCA-associated vasculitides between Japanese and European populations.