[Cytoplasm antibodies of polynuclear neutrophils in Wegener's granulomatosis and systemic vasculitis].

In retrospective and prospective studies the sera of 442 patients recruited from an Internal Medicine department were examined by acetone indirect immunofluorescence and immunoblot in search of anti-neutrophil cytoplasm antibodies (ANCA). Twenty-three patients had Wegener's granulomatosis, and 419 had various control diseases including connective tissue diseases, vasculitis and granulomatosis. The sera from 100 healthy blood donors were used as controls. Among the 23 patients with generalized (n = 15) or localized (n = 8) Wegener's granulomatosis (active in 21/23), the indirect immunofluorescence test was positive in 92 percent of those with the generalized form and in 62 percent of those with the localized form. Nine of the 13 sera examined by immunoblot (69 percent) were positive (31 +/- 57 kDa bands). On the other hand, the sera 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 including 3 neoplasms (10 cases, 35.7 percent). Only 6 of these 28 sera showed a 1/100th titer of ANCA. The sera of all healthy controls were negative. The sensitivity of ANCA for Wegener's granulomatosis at all stages was 72.2 percent, and its specificity 94.4 percent. This study confirms the value of ANCA as third diagnostic criterion of Wegener's granulomatosis, after the clinical and histological criteria.