Unusually indolent MPO-ANCA: associated vasculitis-report of two cases.

Vasculitis associated with antineutrophil cytoplasmic antibodies specific to myeloperoxidase generally presents as a life- and organ-threatening disease that evolves over several months. It is a syndrome in which prompt diagnosis and therapy are important both in terms of short-term survival and long-term organ damage. Two cases with quite a different course, sustained and indolent with limited progression over many years, are described in this report. They are compared to cases in the literature. Indolent cases of granulomatous polyangiitis associated with antineutrophil cytoplasmic antibodies against proteinase-3 are well recognised, but these two cases of microscopic polyangiitis are almost unique.