ANTINEUTROPHIL CYTOPLASM ANTIBODIES IN WE GENERS GRANULOMATOSIS AND SYSTEMIC VASCULITIS

In retrospective and prospective studies the sera of 442 patients recr uited from an Internal Medicine department were examined by acetone in direct immunofluorescence and immunoblot in search of anti-neutrophil cytoplasm antibodies (ANCA). Twenty-three patients had Wegener's granu lomatosis, and 419 had various control diseases including connective t issue diseases, vasculitis and granulomatosis. The sera from 100 healt hy blood donors were used as controls. Among the 23 patients with gene ralized (n = 15) or localized (n = 8) Wegener's granulomatosis (active in 21/23), the indirect immunofluorescence test was positive in 92 pe rcent of those with the generalized form and in 62 percent of those wi th the localized form. Nine of the 13 sera examined by immunoblot (69 percent) were positive (31 +/- 57 kDa bands). On the other hand, the s era from 38 (6.9 percent) patients with control diseases were positive at immunofluorescence: vasculitis (14 cases, 50 percent), connective tissue diseases (4 cases, 14.3 percent) and miscellaneous diseases inc luding 3 neoplasms (10 cases, 35.7 percent). Only 6 of these 28 sera s howed a 1/100th titer of ANCA. The sera of all healthy controls were n egative. The sensitivity of ANCA for Wegener's granulomatosis at all s tages was 72.2 percent, and its specificity 94.4 percent. This study c onfirms the value of ANCA as third diagnostic criterion of Wegener's g ranulomatosis, after the clinical and histological criteria.