Pınar MUTLU, Işıl Deniz ALIRAVCI
Süleyman Demirel Üniversitesi Tıp Fakültesi Dergisi - 2026;33(3):349-358
Objective: To determine the incidence of active TB in patients receiving biological/tsDMARD therapy and to examine the effects of LTBI prophylaxis and the level of immunosuppression on risk. Material and Method: Patients aged >=18 years who started biological treatment between 2019 and 2024 were reviewed retrospectively. Inclusion criteria: >=3 months of biological/tsDMARD use, at least one LTBI test (PPD or IGRA) performed before the treatment, and >=6 months of follow-up records. Exclusions: previous active TB, missing baseline data, or follow-up at an external center. Demographics, diagnosis, agent type/duration, additional immunosuppression, BCG scar, LTBI screening results, prophylaxis regimen, and adverse events were recorded. The primary endpoint was defined as active TB. The relationship between LTBI treatment, level of immunosuppression, LTBI positivity, and active TB was examined using Bayesian logistic regression. Results: A total of 101 patients were reviewed. PPD was performed in 69.1% and IGRA in 51.5% of patients; BCG scar was observed in 93.8%. Two cases of active TB (2.0%) were observed: one developed under baricitinib and the other under bevacizumab. The LTBI prophylaxis completion rate was 71.2%, and hepatotoxicity was 11.9%. Bayesian analysis revealed a high but uncertain risk association with LTBI treatment (OR 57.65; 95% CrI 0.93-3303.16), which was consistent with indication confounding. The likelihood of higher risk was 78% in the low-moderate immunosuppression group. No independent effect of LTBI positivity was observed. Conclusion: Active TB under biological/tsDMARD therapy is rare but important. The high risk seen in those receiving LTBI prophylaxis may be a result of clinicians selecting high-risk patients rather than the treatment itself. The findings achieved in this study suggest that caution is necessary with JAK inhibitors and anti-angiogenic agents and should be confirmed by larger prospective studies.
