An Autopsy Case of Myeloperoxidase-anti-neutrophil Cytoplasmic Antibody (MPO-ANCA) -associated Vasculitis Accompanied by Cryoglobulinemic Vasculitis Affecting the Kidneys, Skin, and Gastrointestinal Tract

Abstract

Anti-neutrophil cytoplasmic antibody (ANCA) -associated vasculitis (AAV) and cryoglobulinemic vasculitis (CV) rarely coexist. An 83-year-old woman was admitted with rapidly progressive renal failure, gastrointestinal hemorrhage and purpura with myeloperoxidase (MPO) -ANCA positivity and cryoglobulinemia. Despite intensive immunosuppressive treatment, she died of aspergillus pneumonia. Autopsy revealed necrotizing crescentic glomerulitis in the majority of the glomeruli, accompanied by partially membranoproliferative-like glomerular changes. Immunofluorescence staining revealed the presence of neutrophil extracellular trap (NET) formation in the glomeruli and cutaneous arteries. These pathological findings suggested that MPO-AAV and/or CV caused NET formation, leading to lethal systemic vasculitis.