Incidence of Tuberculosis in Rheumatoid Arthritis Patients Using Anti-Tumor Necrosis Factor Agents following Latent Tuberculosis Infection Screening Strategies

Abstract

Objective. To compare the incidence of tuberculosis (TB) in rheumatoid arthritis (RA) patients using tumor necrosis factor (TNF) inhibitors following two strategies for latent tuberculosis infection (LTBI) screening: Tuberculin skin test (TST) only vs. TST plus Qauntiferron-TB gold in tube (QFT-GIT). Methods. Data was extracted from a retrospective cohort of Korean RA patients who used biologic agents. Of the 406 RA patients who underwent TST before starting TNF inhibitor, we selected 355 patients who strictly followed LTBI screening and treatment strategies. Two hundred and twenty-two patients were classified as TST only group and the remaining 133 patients as TST plus QFT-GIT group. We calculated the standardized incidence ratio of TB in the entire sample and compared the TB incidence between groups. Results. Among the patients who received the TST only strategy (n=222, 538.6 person-year [PY]), two patients developed TB during anti-TNF therapy, while of those who followed the TST plus QFT-GIT strategy, none developed TB (n=133, 108.8 PY). The overall crude incidence of TB in RA patients using TNF inhibitors was 314 per 100,000 PY. Compared with the general population, the overall age standardized incidence of TB in TNF inhibitor users who followed management guideline for LTBI was 3.9. Conclusion. Despite following screening and management guidelines for LTBI, TB incidence for RA patients during anti-TNF therapy is higher than in the general population. Combining QFT-GIT with TST as a screening for LTBI might be reduce the risk of TB. (J Rheum Dis 2015;22:223- 230)