Özet:

Objective: We aimed to compare the tuberculin skin test (TST) and the interferon gamma release test (IGRT) for latent tuberculosis (LTBI) screening in patient with ankylosing spondylitis (AS) and rheumatoid arthritis (RA) that have two different pathophysiological pathways and the immunosuppressive therapies used.Material-Method: 85 AS and 75 RA patients were included in the study. TST and IGRT for LTBI were performed in patients who were planned biological therapy due to disease activation. TST was applied using the Mantoux method. QuantiFERON-TB Gold PLUS (QFT-GP) was used for IGRT, a fourth version and a ELISA-based test. Results: In the RA group, TST was positive in 27 (36%) patients and negative in 48 (64%) patients. In the QuantiFERON-TB gold test of 27 patients who were found to be positive with TST, 1 (3.7%) was uncertain, 15 (55.5%) patients were negative, and 11 (40.7%) patients were positive. The kappa value of both tests in RA patients was determined to be 0.440 and was considered to be moderate. In the AS group, TST was positive in 44 (51.8) patients and negative in 41 (48.2%) patients. In this group, 34 (77.3%) patients who were found to be positive by TST were evaluated as negative by the QuantiFERON-TB gold test. Agreement of the two tests in AS patients (kappa) was found to be low (0.184).Conclusion: TST and IGRT are not tests with high agreement with each other. Therefore, although TST is recommended primarily in LTBI screening, IGST may be preferred in selected patient groups such as rheumatologic patients.