Clinical Outcome of Rifabutin-based Treatment for Pulmonary Tuberculosis in Solid Organ Transplant Recipients

Backgrounds Rifabutin is often used instead of rifampin to treat tuberculosis (TB) in solid organ transplant recipients (SOTRs) due to fewer drug interactions with immunosuppressants. However, data on its efficacy are limited. Methods A retrospective, case-control study was conducted at a tertiary care center in Korea. SOTRs aged ≥18 years with culture-positive pulmonary TB treated with isoniazid and rifabutin for >80% of the treatment duration were included. Those with rifampin-resistant TB or who discontinued immunosuppressants prior to TB diagnosis were excluded. Each SOTR was matched to three non-SOTR controls treated with rifampin-based regimens. The primary outcome was treatment completion without early relapse. Logistic regression with and without overlap weighting was used for analysis. Results Forty SOTRs and 120 non-SOTRs were analyzed. Baseline TB severity markers (cavitary lesions, smear/culture-positivity) were comparable, but extrapulmonary TB and isoniazid resistance were more common in SOTRs. Treatment duration was longer in SOTRs (median 272 vs 187 days, P <. 001). The primary outcome occurred in 90% of SOTRs and 96.7% of controls (P =. 108). Treatment completion was lower in SOTRs (92.5% vs 100%, P =. 015). No significant differences were observed in TB recurrence or 1-year mortality. TB-attributable deaths were absent in both groups. After overlap weighting, no significant difference was found in the primary outcome (aOR 0.36; 95% confidence interval, 0.01-10.41). Allograft rejection and failure occurred in 10% and 12.5% of SOTRs, respectively. Conclusions Rifabutin-based therapy in SOTRs achieved treatment outcomes comparable to rifampin-based regimens in non-SOTRs, supporting its use in this population.