[Clinical investigation of anti-myeloperoxidase antibodies in patients with glomerulonephritis with crescent formation].

Anti-neutrophil cytoplasmic antibodies (ANCA) have been found in patients with systemic vasculitis and crescentic glomerulonephritis. Recently two types of ANCA were identified, one is anti-myeloperoxidase antibodies (Anti-MPO Ab) stained perinuclear pattern of alcohol-fixed neutrophils by immunofluorescence test, and the other is autoantibodies with no reactivity with myeloperoxidase stained diffuse cytoplasmic pattern (C-ANCA). We investigated 59 patients with various glomerulonephritis with or without crescent to detect anti-MPO Ab and C-ANCA by an enzyme-linked immunosorbent assay. The results were as follows: 1) Anti-MPO Ab were detected only in patients with various glomerulonephritis with crescent. 2) Titers of anti-MPO Ab were high related to percentage of crescent in some cases of glomerulonephritis. 3) Titers of anti-MPO Ab were elevated at stage of cellular and fibro-cellular crescent. 4) C-ANCA were detected only in patients with Wegener's granulomatosis. These data suggested that anti-MPO Ab may play important roles in crescent formation and may be a marker of crescent formation in various glomerulonephritis.