Rationale of concomitant cyclophosphamide for remission-induction in patients with antineutrophil cytoplasmic antibody-associated vasculitis: A propensity score-matched analysis of two nationwide prospective cohort studies.

We evaluated the effectiveness of cyclophosphamide for patients with microscopic polyangiitis and granulomatosis with polyangiitis. Patients treated with cyclophosphamide and glucocorticoid (cyclophosphamide group) or glucocorticoid alone (non-cyclophosphamide group) for remission-induction were enrolled from two Japanese nationwide prospective inception cohort studies. The effectiveness and safety outcomes were compared before and after propensity score (PS)- matching. Proportion of patients achieving Birmingham Vasculitis Activity Score (BVAS)-remission and BVAS-remission plus a daily prednisolone dosage of ≤10 mg (GC-remission) by Month 6 were not significantly different between cyclophosphamide and non-cyclophosphamide groups before ( Concomitant cyclophosphamide use may improve GC-remission by Month 6 in MPO-ANCA-positive patients and could exert glucocorticoid sparing effect.