Antineutrophil cytoplasm antibody in crescentic glomerulonephritis.

Antineutrophil cytoplasm antibody (ANCA) has been reported in the sera of adults with Wegener''s granulomatosis and microscopic polyarteritis, but this phenomenon has not so far been described in children. We report three children with crescentic glomerulonephritis in whom ANCA concentrations were raised at presentation. Two cases were idiopathic, and the other later developed features of Wegener''s granulomatosis. In all three, plasma exchange and immunosuppression removed ANCA, but in only one case was there clinical improvement. This child later developed classical nasal lesions of Wegener''s granulomatosis associated with a decline in renal function and a rise in ANCA. Plasma exchange and immunosuppression again produced a good clinical response and removed ANCA. This suggests that ANCA is either a marker of disease activity, or is involved in the pathogenesis of disease.