THU0226 Serial interferon-gamma release assays in patients with rheumatoid arthritis treated with biologic agents

Background It is increasing attention about the risk of latent tuberculosis infection (LTBI) reactivation during the treatment of biologic agents for patients with rheumatoid arthritis. Taiwan rheumatology association recommend performing at least annual interferon-gamma release assays (IGARs) testing during biologic treatment course because of the moderate prevalence of tuberculosis in Taiwan.[1 Although several studies have reported the risk of active tuberculosis infection in patients with rheumatoid arthritis (RA), the long-term serial IGARs testing in patients with RA is limited. Objectives The aims of this study is to use serial interferon-gamma release assays(IGRAs) as a screening tool in patients with rheumatoid arthritis treated with different biologic agents in Taiwan. Methods We retrospectively collected 189 patients with rheumatoid arthritis receiving biologic agents between 2013 to 2017 in Chang Gung Memorial hospital in Taiwan. All RA patients underwent semi-annual IGRA test during biologic agents treatment. Results The seroconversion rate of IGAR in patients with rheumatoid arthritis after biologic treatment is 6.9%. The median seroconversion period is 19 months. Out of the 13 patients with seroconversion, 8 (61.5%) patients were treated with TNF block and 5 (38.5%) patients were treated with non-TNF blocker. All the patients with seroconversion evaluate the possible active TB infection and 69.2% (9/13) received chemoprophylactic therapy by isoniazid. There is no active tuberculosis infection during serial IGAR tests. The risk factor included high baseline TBAg-nil/nil (OR 3.44, CI 6.64–1.78), leflunomide(OR 11.51, CI 61.34–2.16). Conclusions Our study revealed patients with rheumatoid arthritis receiving long-term biologic therapy had a low rate IGAR seroconversion rate (6.9%). Patients with background Leflunomide had higher odds ratio of seroconversion. However, the clinical importance of IGAR serocoversion remain controversial and further long-term large scale investigation is needed. Reference [1] Chen Y-H. 2015TRA revised recommendations for screening and management of tuberculosis infection in patients before and after anti-tumor necrosis factor-alpha biological treatment. 2015;29:1–8. Disclosure of Interest None declared