Renal artery stenosis modifies glomerular injury in antineutrophil cytoplasmic antibody-associated disease

A 68-year-old man presented with renal failure, heart failure, gastrointestinal bleeding, and a pulmonary infiltrate. Serologic evaluation revealed a perinuclear antineutrophil cytoplasmic antibody (ANCA) at a titer of 1:1280, which on immunoblot and enzyme immunoassay showed antimyeloperoxidase specificity. Autopsy showed microscopic polyarteritis based on the presence of necrotizing alveolitis and crescentic glomerulonephritis. The extent and activity of the glomerular disease was modified by a right renal artery stenosis (RAS). Twenty percent of glomeruli on the right and 82% glomeruli on the left contained crescentic lesions. Furthermore, predominantly active lesions were associated with renal artery stenosis, while the contralateral kidney contained mostly organized crescents. This observation suggests that hemodynamic factors or its sequelae can influence the onset and severity of ANCA-associated disease.