Objective: Rheumatoid arthritis (RA) is a systemic autoimmune disease of unknown etiology with chronic joint inflammation. The major autoantibody detected in RA patients is rheumatoid factor (RF). RF has demonstrated lower sensitivity for the diagnosis of RA. The aims of this study were to evaluate the diagnostic performance of anti-cyclic citrullinated peptide (anti-CCP) by ELISA method and compared those with the diagnostic performance of RF test in patients with RA, and to determine how frequently anti-CCP antibodies can be found in patients with asthma, systemic lupus erythematosus, and in normal blood donors and control groups.

Materials and Methods: Diagnostic performance of anti-CCP assay by enzyme linked immunosorbent assay (ELISA) was compared with that of RF by nephelometry test. RF and anti-CCP tests were performed in 23 RA patient, 23 healthy control groups, 20 asthma, 7 systemic lupus erythematosus, and 15 normal blood donors.

Results: However, anti-CCP antibody showed positivity in 95.7% of RA patient and 4.3% of healthy control groups, this autoantibody has demonstrated negativity for asthma, systemic lupus erythematosus, and normal blood donors. In the RA groups, sensitivity and specificity were 95.7% and 95.7% for anti-CCP, and 100% and 78.3% for RF antibody, respectively.

Conclusion: It was considered that anti-CCP could be very useful serological assay for the diagnosis of RA, because anti-CCP revealed higher diagnostic specificity than RF.