RT Journal Article SR Electronic T1 Clinical outcomes of treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis based on ANCA type JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 1166 OP 1169 DO 10.1136/annrheumdis-2015-208073 VO 75 IS 6 A1 Sebastian Unizony A1 Miguel Villarreal A1 Eli M Miloslavsky A1 Na Lu A1 Peter A Merkel A1 Robert Spiera A1 Philip Seo A1 Carol A Langford A1 Gary S Hoffman A1 CG M Kallenberg A1 E William St. Clair A1 David Ikle A1 Nadia K Tchao A1 Linna Ding A1 Paul Brunetta A1 Hyon K Choi A1 Paul A Monach A1 Fernando Fervenza A1 John H Stone A1 Ulrich Specks YR 2016 UL http://ard.bmj.com/content/75/6/1166.abstract AB Objective To evaluate whether the classification of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) according to ANCA type (anti-proteinase 3 (PR3) or anti-myeloperoxidase (MPO) antibodies) predicts treatment response.Methods Treatment responses were assessed among patients enrolled in the Rituximab in ANCA-associated Vasculitis trial according to both AAV diagnosis (granulomatosis with polyangiitis (GPA)/microscopic polyangiitis (MPA)) and ANCA type (PR3-AAV/MPO-AAV). Complete remission (CR) was defined as disease activity score of 0 and successful completion of the prednisone taper.Results PR3-AAV patients treated with rituximab (RTX) achieved CR at 6 months more frequently than did those randomised to cyclophosphamide (CYC)/azathioprine (AZA) (65% vs 48%; p=0.04). The OR for CR at 6 months among PR3-AAV patients treated with RTX as opposed to CYC/AZA was 2.11 (95% CI 1.04 to 4.30) in analyses adjusted for age, sex and new-onset versus relapsing disease at baseline. PR3-AAV patients with relapsing disease achieved CR more often following RTX treatment at 6 months (OR 3.57; 95% CI 1.43 to 8.93), 12 months (OR 4.32; 95% CI 1.53 to 12.15) and 18 months (OR 3.06; 95% CI 1.05 to 8.97). No association between treatment and CR was observed in the MPO-AAV patient subset or in groups divided according to AAV diagnosis.Conclusions Patients with PR3-AAV respond better to RTX than to CYC/AZA. An ANCA type-based classification may guide immunosuppression in AAV.Trial registration number NCT00104299; post-results.