In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis is a severe condition encompassing two major syndromes: granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) and microscopic polyangiitis. Its cause is unknown, and there is debate about whether it is a single disease entity and what role ANCA plays in its pathogenesis. We investigated its genetic basis. A genomewide association study was performed in a discovery cohort of 1233 U.K. patients with ANCA-associated vasculitis and 5884 controls and was replicated in 1454 Northern European case patients and 1666 controls. Quality control, population stratification, and statistical analyses were performed according to standard criteria. We found both major-histocompatibility-complex (MHC) and non-MHC associations with ANCA-associated vasculitis and also that granulomatosis with polyangiitis and microscopic polyangiitis were genetically distinct. The strongest genetic associations were with the antigenic specificity of ANCA, not with the clinical syndrome. Anti–proteinase 3 ANCA was associated with HLA-DP and the genes encoding α₁-antitrypsin (SERPINA1) and proteinase 3 (PRTN3) (P=6.2×10⁻⁸⁹, P=5.6×10^−12, and P=2.6×10⁻⁷, respectively). Anti–myeloperoxidase ANCA was associated with HLA-DQ (P=2.1×10⁻⁸). This study confirms that the pathogenesis of ANCA-associated vasculitis has a genetic component, shows genetic distinctions between granulomatosis with polyangiitis and microscopic polyangiitis that are associated with ANCA specificity, and suggests that the response against the autoantigen proteinase 3 is a central pathogenic feature of proteinase 3 ANCA–associated vasculitis. These data provide preliminary support for the concept that proteinase 3 ANCA–associated vasculitis and myeloperoxidase ANCA–associated vasculitis are distinct autoimmune syndromes. (Funded by the British Heart Foundation and others.)

Objective To contrast the effect of the burden of vasculitis activity with the burden of adverse events on 1-year mortality of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Methods This study assessed the outcome and adverse events in patients prospectively recruited to four European AAV clinical trials. Data on 524 patients with newly diagnosed AAV were included. The burden of adverse events was quantified using a severity score for leucopenia, infection and other adverse events, with an additional weighting for follow-up duration. A ‘combined burden of events’ (CBOE) score was generated for each patient by summing the individual scores. Vasculitis severity was quantified using the Birmingham vasculitis activity score and glomerular filtration rate (GFR). Results 1-year mortality probability was 11.1%; 59% and 14% of deaths were caused by therapy-associated adverse events and active vasculitis, respectively. Using Cox regression analysis, infection score (p<0.001), adverse event score (p<0.001), leucopenia score (p<0.001) and GFR (p=0.002) were independently associated with mortality. The risk of 1-year mortality remained low (5%) with CBOE scores less than 7, but increased dramatically with scores above this. Hazard ratio for death with a CBOE greater than 7 was 14.4 (95% CI 8.4 to 24.8). Age and GFR were independent predictors of CBOE score. Conclusions The greatest threat to patients with AAV in the first year of therapy is from adverse events rather than active vasculitis. The accumulation of adverse events, monitored using this scoring method, should prompt increased awareness that the patient is at high risk of death.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare inflammatory disease of unknown cause. 30% of patients have anti-neutrophil cytoplasmic antibodies (ANCA) specific for myeloperoxidase (MPO). Here, we describe a genome-wide association study in 676 EGPA cases and 6809 controls, that identifies 4 EGPA-associated loci through conventional case-control analysis, and 4 additional associations through a conditional false discovery rate approach. Many variants are also associated with asthma and six are associated with eosinophil count in the general population. Through Mendelian randomisation, we show that a primary tendency to eosinophilia contributes to EGPA susceptibility. Stratification by ANCA reveals that EGPA comprises two genetically and clinically distinct syndromes. MPO+ ANCA EGPA is an eosinophilic autoimmune disease sharing certain clinical features and an HLA-DQ association with MPO+ ANCA-associated vasculitis, while ANCA-negative EGPA may instead have a mucosal/barrier dysfunction origin. Four candidate genes are targets of therapies in development, supporting their exploration in EGPA.