Original paper
Antineutrophil cytoplasmic antibodies in patients with rheumatoid arthritis

NCA occur in vasculitis, including Wegener’s granulomatosis and Churg-Strauss syndrome. Their presence in some other rheumatic diseases has been well documented. The frequency and clinical significance of ANCA in patients with rheumatoid arthritis are not well established. The aim of the study was to evaluate the prevalence and specificity of antineutrophil cytoplasmic antibodies in patients with rheumatoid arthritis. Serum samples were obtained from 377 patients with rheumatoid arthritis without symptoms of vasculitis. The control group samples were taken from 183 patients with osteoarthritis. ANCA titers and type were determinated by indirect immunofluorescence method (IIF). Antigenic specificity was detected by ELISA method. ANCA were found by IIF in 17.8% patients with rheumatoid arthritis. A perinuclear pattern of ANCA was observed in 70.2% and atypical ANCA in 29.8% of cases. We have not observed C-ANCA as well as the reactivity against proteinase 3. In 8.9% serum samples, ANCA yielded reactivity against mieloperoxidase, in 40.3% against lactoferrin and in 8.8% against lisozyme. In 20.9% cases the antibodies have indicated reactivity against catepsin G and elastase. IgM-ANCA were detected in 7.5% and IgG-ANCA in 92.5% cases. In 58% it was IgG1 class and in 24.1% IgG3.