The Risk of Serious Infections in Patients with Rheumatoid Arthritis Treated with Different Tumor Necrosis Factor a Inhibitors

Abstract

Objective: To evaluate the risk of serious infection in patients with rheumatoid arthritis (RA) treated with etanercept or adalimumab between 2007 and 2012 in a single medical center. Methods: We retrospectively collected the demographic data, clinical characteristics, laboratory findings, and all episodes of serious infection during anti-tumor necrosis factor (TNF)-α therapy. The incidence rate was calculated from the observed number of serious infections and patient-years of follow-up. Univariate and multivariate logistic regression analyses were made to identify the independent predictors of serious infection. Results: A total of 595 patients were included in the analyses: 319 (54%) treated with etanercept and 276 (46%) treated with adalimumab. The overall incidence rate was 6.45/100 patient-years: 5.05/100 patient-years for etanercept and 8.28/100 patient-years for adalimumab. The risk of serious infection was significantly higher in adalimumab than in etanercept (adjusted OR: 2.01, 95% CI: 1.15-3.49, p=0.014). Advanced age at the start of TNF-α inhibitor therapy and chronic pulmonary diseases were associated with significantly higher independent risks for serious infection. Conclusion: The risk of serious infection in RA patients treated with adalimumab was significantly higher than that in RA patients treated with etanercept in this cohort.