Clinical trial for Japanese patients with myeloperoxidase anti-neutrophil cytoplasmic antibody-associated vasculitis: the JMAAV study.

In view of the marked difference in epidemiology of myeloperoxidase/proteinase 3 anti-neutrophil cytoplasmic antibody (MPO/PR3-ANCA)-associated vasculitis between Japan and Western countries, a prospective, open-label, multi-center trial (Japanese Patients with MPO-ANCA-Associated Vasculitis; JMAAV) was performed to evaluate the usefulness of severity-based treatment in Japanese patients with newly diagnosed MPO-ANCA-associated vasculitis. Among the 47 patients enrolled and prescribed predefined therapies, 42 achieved remission within 6 months (89%), 5 died (11%), and 1 developed end-stage renal disease (2%). Disease relapsed in 8 of the 42 patients with remission during the 18-month follow-up period (19%). The remission and death rates were comparable to several previous clinical trials performed in Western counties. Relapse and severe infection, however, appeared to be more frequent than in previous trials, and therefore should be investigated further in future trials. Subsidiary analysis was also performed using samples from these patients, and a new serum biomarker for microscopic polyangiitis and a novel gene expression profile of peripheral blood to predict response to treatment were found by proteomic and transcriptomic analysis, respectively.