Possible Role of Anti-Cyclic Citrullinated Peptide Antibody (Anti-CCP Ab) in Rheumatic Diseases

Background: Anti-cyclic citrullinated peptide (anti-CCP) antibodies are highly specific for RA, but are not detectable in all RA patients, in addition their usefulness to identify rheumatic arthritis (RA) from other rheumatic diseases presenting with joint pain is not well studied. Aim: To establish whether the clinical phenotypes of anti-CCP positive and negative disease are distinct at the earliest clinically apparent phase of disease and to assess the diagnostic accuracy of the anti-CCP antibodies assay to separate RA patients from a group of patients with (SLE). Patients and Methods: One hindered ten blood samples were collected from patients, 75 with RA (58 seropositive and 17 seronegative) and 35 patients with SLE attending the Rheumatology Clinic of the Al-Yarmook Teaching Hospital for period between March 2009 and November of 2010 were included in this study. Then sera were stored at -20° and tested for anti-CCP antibodies by a commercially available enzyme-linked immunosorbent assay (ELISA) kit (Euroimmun, while CRP and Rheumatoid factor was test by latex agglutination (LA). Results: Forty five of 58 seropositive RA patients (77.6%) were positive for anti-CCP, while 13 patients tested negative for anti-CCP antibodies. Among the seronegative group, antibodies to anti-CCP could be demonstrated in 22.4% of patients. Anti-CCP positive patients were rheumatoid factor positive (77.6% vs. 22.4%, p < 0.005). There was no significant difference in the pattern of joint involvement. In the SLE group, anti-CCP antibody was positive in only 8 of 35 (22.8 %) patients. Conclusions: Patients with and without anti-CCP antibodies present in a similar way, and anti-CCP antibody have high sensitivity for diagnosis of RA