MPO-ANCA-associated small vessel vasculitis presenting as fever of unknown origin. Report of one case.

Microscopic polyangiitis (MPA) is an antineutrophil cytoplasmic antibody (ANCA) associated small vessel vasculitis which can present with various clinical manifestations, for which the mainstay of treatment is systemic corticosteroids and immunosuppressants. We report a case of a 54-year-old female admitted to the hospital because of fever during the last month, leukocytosis and elevated erythrocyte sedimentation rate. Persistence of elevated serum creatinine levels and accompanying hematuria led us to perform a renal biopsy, and MPA was diagnosed on the basis of light and immunofluorescence microscopy. Remission was induced with oral corticosteroids and cyclophosphamide therapy in conjunction with plasmapheresis (PF). The objective of this report was to assess the role of PF in the treatment of MPA and report on its utility in patients with MPA who are not responding to standard therapy or who require unacceptably high doses of steroids or immunosuppressants. In a patient presenting with fever of unknown origin, microscopic polyangiitis should also be considered in the differential diagnosis. Copyright 2002 S. Karger AG, Basel