Comparative study of anti-CCP and RF for the diagnosis of rheumatoid arthritis
Aim: To determine the frequency of anti-cyclic citrullinated peptide antibody (anti-CCP) in a group of patients with rheumatoid arthritis and another group with other rheumatic diseases. Patients and methods: Anti-CCP1 and rheumatoid factor (RF) titres were determined in 320 serum samples; 136 from RA patients, 184 from control patients (165 patients with rheumatic diseases other than RA, and 21 patients with lymphoproliferative diseases). Results: The sensitivity of Anti-CCP was 62.5% (95% CI: 53-70%) for the diagnosis of RA with a specificity of 89.1% (95% CI: 83-93%). The sensitivity of RF was 85.3% (95% CI: 79-91%). The specificity was 64.7% (95% CI: 57-71%). Conclusions: Anti-CCP1 has not very high specificity for RA regarding other rheumatic disease. However it is still very helpful for the diagnosis of RA. © 2007 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd.