Treatment of ANCA-associated vasculitides: Certainties and controversies.

Antineutrophil cytoplasm antibodies (ANCA)-associated vasculitides are necrotizing vasculitis affecting small blood vessels and include granulomatosis with polyangiitis (formerly Wegener's), microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome). Diagnosis of ANCA-associated vasculitis is based on the clinical presentation, ANCA positivity directed against proteinase 3 or myeloperoxidase, and when possible on histological evidence of vasculitis. Evolution of ANCA-associated vasculitides without treatment leads constantly to death. Under treatment, overall survival has considerably improved during the last decades, and the long-term prognosis is mainly conditioned by disease sequelae, relapses and treatment-related toxicity, especially infections and cardiovascular events. Treatment is based on an induction phase followed by maintenance. During the induction phase, glucocorticoids must be associated in most cases with cyclophosphamide or rituximab. Maintenance phase, aiming at preventing relapses particularly frequent with ANCA directed against proteinase 3, is based on rituximab, but optimal dose and duration has still to be determined.