Sensitivity and specificity of anti-cyclic citrullinate peptide antibody and IGM rheumatoid factor in serologic diagnosis of rheumatoid arthritis

Introduction. In recent years, anti-cyclic citrullinated peptide (anti-CCP) antibodies have been used as highly specific and sensitive markers in diagnosis of rheumatoid arthritis (RA). The aim ot he study was to determine sensitivity and specificity of anti-CCP antibodies and IgM rheumatoid factor in patients with RA and their association with serological markers of disease activity. Methods. We retrospectively analyzed 60 patients with RA and 40 without RA (with other rheumatoid disease) who had attended the Rheumatology Clinic because of joint pain in the first six months of 2009. The following parameters were studied: age, sex, disease duration, morning stiffness, familiar history, erythrocyte sedimentation rate, haematocrit, number of leucocytes and trombocytes, CRP, IgM RF, anti-CCP, DAS (disease activity score) 28, and joint erosion. Results. Sensitivity and specificity of anti-CCP antibodies for rheumatoid arthritis diagnosis, based on American Rheumatoid Association were 66.7% and 95%, respectively. Sensitivity and specificity for IgM RF were 71.2% and 82.5%, respectively. There was no significant difference between anti-CCP(+) and anti-CCP(-) as well as between RF(+) and RF(-) groups for the analyzed parameters. There was a significant correlation between anti-CCP and IgM RF (r=0.51, p