Method: Anti-CCP was measured by ELISA. Disease activity and its clinical improvement were assessed using Disease Activity Scores [DAS28; erythrocyte sedimentation rate (ESR) 4] with European League Against Rheumatism (EULAR) response criteria.
Result: In the present study, 64 patients with RA treated with biological agents (infliximab; 30, etanercept; 19, tocilizumab; 7, adalimumab; 8) were included. The mean age was 36.0±18.0 yrs, mean disease duration was 7.8±4.1 yrs, and mean baseline DAS28 was 5.42±1.47. Among the 64 RA patients, 55 patients (85.9%) were positive for anti-CCP, and the mean antibody titer was 293.1±733.4 U/ml. After 14 weeks of treatment, 26 patients showed good responses and 30 moderate responses to biologic agents based on EULAR response criteria, while 8 showed no clinical improvement.
The anti-CCP titer was 73.7±112.1 U/ml in the good responders and 230.3±261.5 U/ml in the moderate responders, which were significantly lower than in the non-responders (1335±1791.5 U/ml). In addition, 100% of patients with low (<100 U/ml) basal anti-CCP titers showed moderate-good response, and 88.0 % of those with moderate (100-499 U/ml) titers also showed a moderate-good response. Among those with higher (≥500 pg/ml) basal anti-CCP titers, 50% showed a moderate response and 50% no response. In addition, the anti-CCP titer was 85.9±879.1 U/ml in the group with remission at 14weeks, although significant higher titers of anti-CCP (396.8±129.2 U/ml) were seen in those had no remission.
Conclusion: The result suggests that anti-CCP titer might to be one of significant predictors of the efficacy of the biological agents in patients with RA.
Disclosure: R. Takahashi, None; R. Yanai, None; H. Furuya, None; K. Wakabayashi, None; T. Odai, None; T. Isozaki, None; N. Yajima, None; Y. Miwa, None; T. Kasama, None.