Diagnostic utility of an anti-CCP point-of-care immunotest in Chinese patients with rheumatoid arthritis

Background: Early and accurate diagnosis of rheumatoid arthritis (RA) has become increasingly important. The clinical significance of anti-cyclic citrullinated peptide (CCP) antibody in Chinese RA adults was studied using an anti-CCP2 rapid test. Methods: Anti-CCP antibody and rheumatoid factor (RF) were determined in 95 RA patients and 140 patients with rheumatic diseases other than RA. Results: Two hundred and thirty five subjects were enrolled in this study. Both sensitivity and specificity of anti-CCP2 ELISA (78.9% & 95.7%) were higher than those of RF (67.4% & 84.3%). The area under the receiver operating characteristic curve for anti-CCP2 ELISA was 0.852 (95% CI: 0.792-0.913) which was larger than that for RF 0.775 (95% CI: 0.710-0.840). Both sensitivity and specificity (75.8% and 92.9%) of the anti-CCP2 rapid test were comparable to the ELISA. However, the sensitivity (62.1%) of a combined strategy by measuring anti-CCP antibody and RF was even lower than either marker alone although the specificity (98.6%) was slightly improved. Conclusions: Anti-CCP antibody is a valuable tool for diagnosis of RA in Chinese patients. With the use of the reliable and user-friendly anti-CCP rapid test, it may have an important role in the design of therapeutic strategies in RA patients. (C) 2011 Elsevier B.V. All rights reserved