A rise in antineutrophil cytoplasmic antibody in a patient with systemic vasculitis in remission.

We report a 42-year-old man who showed alveolar hemorrhage and glomerulonephritis as well as episcleritis and skin rash. He had an extremely high titer of cytoplasm-staining antineutrophil cytoplasmic antibody (C-ANCA) and was diagnosed as having systemic vasculitis based on histological findings of kidney and skin biopsies. After immunosuppressive therapy clinical manifestations resolved within several weeks and C-ANCA titers commensurably declined. C-ANCA titers, however, increased again and remained high despite clinical remission. In general, there is a close relationship between ANCA titers and clinical activities in ANCA-associated diseases, but they displayed a large discrepancy in this patient. Indeed, the serum of the patient in remission contained the antibody against 29-kD neutrophil extracts which was detected by immunoblot analysis. These findings suggest that C-ANCA may not necessarily be, by itself, pathogenetic for the development of the vasculitis.