Microscopic polyangiitis with lung-kidney syndrome

case report and literature review

Abstract

Microscopic polyangiitis (MPA) is a pauci-immune systemic necrotizing vasculitis associated with neutrophil anti-cytoplasmic antibody (ANCA) with a preference for small vessels. Case report: We report the case of a 54-year-old woman, who presented migratory polyarthritis in wrists, knees and ankles associated with progressive morning stiffness, with history of malar "rash", photosensitivity and alopecia. It progressed throughout the year of 2017 with deterioration of renal function and pulmonary hemorrhage, requiring intensive care. Renal biopsy suggested a pattern compatible with pauci-immune glomerulonephritis and the diagnosis of microscopic polyangiitis was suggested. She underwent pulse therapy with methylprednisolone and cyclophosphamide, in addition to plasmapheresis, being discharged from hospital after stabilization of the clinical condition. Importance of the issue: The present case reveals an uncommon and high morbimortality complication of MPA. The negativity of the ANCA made diagnosis difficult, and a renal biopsy was necessary to confirm diagnosis. Lung-kidney syndrome is potentially fatal if the treatment is not instituted early.