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.