Pathology of Antineutrophil Cytoplasmic Antibody–Associated Pulmonary and Renal Disease

Abstract

Context.—Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis commonly presents with pulmonary and renal involvement that may present diagnostic challenges. Objectives.—To highlight the updates in the classification of small vessel vasculitis, present the patterns of pulmonary and renal pathology in which ANCA-associated vasculitis is included in the differential diagnosis, analyze the screening and specific antineutrophil cytoplasmic antibody testing methods in the clinical laboratory, compare and contrast the 3 major ANCA-associated vasculitis diseases, and review the pathophysiologic mechanisms of tissue injury in this setting. Data Sources.—Data are derived from published literature and clinical experience. Conclusions.—Although rare, ANCA-associated vasculitis diseases are often considered in the differential diagnosis of many pathologic patterns of pulmonary and renal disease. Histopathologic diagnosis of specific entities in this context nearly always requires correlation of the pathology with clinical and serologic data.