[Prevalence and specificity of antineutrophil cytoplasmic antibodies (ANCA) in connective tissue diseases].

Antineutrophil cytoplasmic antibodies (ANCA) have specificity for constituents of neutrophil granules. There are two different types of ANCA identifiable by indirect immunofluorescence method. One type produces the cytoplasmic staining pattern (C-ANCA) and the second-perinuclear (P-ANCA). The aim of the study was to evaluate the frequency of ANCA in patients with connective tissue diseases (CTD). Serum samples were obtained from 394 patients suffering from CTD. The patients group consisted of 86 patients with lupus erythematosus systemic (LES) (including 30 with LES accompanied with glomerulonephritis), 136 cases with rheumatoid arthritis (RA) (including 18 patients with RA and vasculitis), 42 patients with systemic sclerosis (SSc), 76 cases of Sjögren's syndrome (SS), 30 with Wegener's granulomatosis (WG), and 24 patients with polyarteritis nodosa (PAN). All patients fulfilled ARA criteria for the classification of CTD. The control group consisted of 42 healthy individuals. ANCA were detected by immunofluorescence method according to Wiik, and by an antigen-specific--enzyme-linked immunosorbent assay (ELISA). Proteinase 3 (PR-3), myeloperoxidase (MPO), elastase (ELA), lactoferrin (LC) and lysozyme (LZ), as well as cathepsin G were used as antigens in ELISA method. ANCA were detected in sera of 86 (21.8%) patients with CTD. C-ANCA pattern was observed in 28 (7.1%) cases, and p-ANCA in 58 (14.7%). C-ANCA were detected in sera of 28 (93%) patients with WG. P-ANCA were showed in 12 (13.9%) patients with LES, in 12 (50%) cases with PAN, in 20 (14.7%) with RA, in sera of 4 (9.5%) patients with SSc and in 10 (13.1%) with SS. No ANCAs were detected in healthy individuals. Ani-PR-3 antibodies were showed in sera of 26 patients, anti MPO in 30 cases, anti-ELA in sera of 12 patients, and anti-LC in 14 cases, but anti-LZ in 4 patients with CTD. The presence of ANCA in CTD patients may indicate the vascular inflammatory process during the course of the disease. It is a very important factor for the clinical course, and prognosis in the CTD patients.