Treatment of severe and/or refractory ANCA-associated vasculitis.

Most patients presenting with systemic necrotizing vasculitides improve when they are adequately treated. The presence of life-threatening manifestations or visceral involvement modifying organ function characterizes severe vasculitis, confirmed by disease-severity scores. Sequelae cannot always be predicted and prevented but organ involvement present at disease onset requires rapid therapeutic intervention. Some patients present a persistent active disease, which does not respond to treatments and deserve other drugs or combination of drugs. The therapeutic options for severe and/or relapsing and refractory diseases are described.