Diagnostic accuracy of anti-cyclic citrullinated peptide antibodies in juvenile idiopathic arthritis.

OBJECTIVE To correlate serum anti-cyclic citrullinated peptide antibodies (anti-CCP) levels with juvenile idiopathic arthritis (JIA) subtypes and with an erosive disease course. METHODS The study group comprised 122 children with JIA; 16 were evaluated during both active disease and remission. Nineteen children with systemic lupus erythematosus (SLE), 27 with rheumatoid arthritis (RA), and 15 healthy children were also included in the study. Twelve children with JIA were rheumatoid factor (RF) positive, and 34 patients had persistent erosive joint disease. Anti-CCP antibody levels were determined by ELISA; values above 5 relative units were regarded as positive. RESULTS Three girls with seropositive polyarticular JIA and erosive joint disease had positive anti-CCP values. Children evaluated during active disease and remission, patients with SLE, and healthy children all had negative anti-CCP antibody levels. However, 19/27 (70%) adult patients with RA had positive anti-CCP antibody values. CONCLUSIONS In contrast with RA, anti-CCP positivity is only rarely found in patients with JIA. In patients with RF positivity and/or in patients with erosive joint disease, anti-CCP can be detected.