[Antineutrophil cytoplasmic antibodies (ANCA): clinico-pathologic correlations iin a series of 82 cases].

OBJECTIVE: Antineutrophil cytoplasmic antibodies (ANCA) have been described in a great variety of diseases in addition to the ANCA-associated systemic vasculitis (Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS)) and the pauci-immune rapidly progressive glomerulonephritis (RPGN). The objective of this work is to describe the clinical-pathological diagnosis of a series of patients with ANCA. MATERIAL AND METHODS: Retrospective review of patients with positive ANCA by indirect immunofluorescence in our hospital between January 1997 and December 1998. RESULTS: We identify 82 patients with ANCA. Six cases (7.3%) showed a C-ANCA pattern, 19 (23.2%) a P-ANCA pattern and 57 (69.5%) an atypical pattern. Eight patients (9.7%) had an ANCA-associated systemic vasculitis (5 WG, 2 MPA and 1 SCS). Four patients (4.9%) had a pauci-immune RPGN without systemic vasculitis. One only case (1.2%) in our series presented a C-ANCA pattern without evidence of an ANCA-associated systemic vasculitis or a pauci-immune RPGN. CONCLUSIONS: The atypical pattern is the most frequent in patients with ANCA. A minority of patients with ANCA have an ANCA-associated systemic vasculitis (WG, MPA or SCS) or a pauci-immune RPGN. The occurrence of a C-ANCA pattern is exceptional in patients without an ANCA-associated systemic vasculitis or a pauci-immune RPGN.