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

Abstract

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.