Evaluation of the Value of Anti-Citrullinated α-enolase Peptide 1 Antibody in the Diagnosis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease. The alpha enolase is a nuclear glycolytic enzyme. Antibodies to citrullinated-enolase peptidel (anti-CEP-1) are found in approximately 40% of patients with RA, but the diagnostic value of anti-CEP-1 for RA is not clear. Methods. We enrolled 282 patients with RA according to the 2010 ACR Classification criteria, referred to the department of Rheumatology in Peking University Third Hospital, 120 sex-and age-matched healthy donors (HD), and 30 patients with osteoarthritis (OA). Anti-CEP-1 IgG antibodies were assessed with a commercially available ELISA kit (Euroimmun, Germany) according to the manufacturers' instructions. Anti-CCP antibodies were assessed with ECLIA (Roche, Germany). Data was processed with SPSS 19. The scatter diagram was drawn in GraphPad Prism. Results. The specificity and sensitivity was 83.3% and 65.2%, respectively. The positive predictive value was 88% and the negative predictive value was 56%. The AUC of anti-CEP1 for diagnosis of RA is 0.80, while that of Anti-CCP is 0.919; the value of anti-CCP combined with anti-CEPI is 0.914. Ten anti-CEPI positive results are found in 48 patients of RA with anti-CCP negative result. Conclusion. The anti-CEP-1 is suitable for diagnosing of RA, but not superior to anti-CCP.