Risk factors of tuberculosis after liver transplant in a tertiary care hospital

Background: Tuberculosis (TB) is a serious opportunistic infection in liver transplant (LT) recipients with a high rate of morbidity and mortality. This study aims to clarify the frequency and risk factors for tuberculosis in LT recipients. Methods: A total of 884 LT recipients were investigated retrospectively at China Medical University Hospital, Taichung, Taiwan. We performed a case–control study (1:2) to investigate the potential risk factors and disease onset of TB after LT. Results: Among the 884 LT recipients, 25 of TB cases (2.8%) were reported from 2009 to 2016. The overall incidence of TB was 744 cases per 100,000 patient-year, which was 18-fold higher than the general population in Taiwan. The median time to develop TB after liver transplant was 20 months. Of the TB cases, 15 were pulmonary TB and 10 were extra-pulmonary TB. Five cases of those extra-pulmonary TB occurred in the first post-transplant year. Overall five-year survival rate was 63.3%. Multivariate analyses identified apical fibrotic change in pre-transplant computed tomographic (CT) finding and the exposure to mammalian target of rapamycin (mTOR) inhibitors before TB event as independent risk factors for TB development (Odd ratio (OR) 10.79, 95% confidence interval (CI), 1.73–67.49, p = 0.01; OR 3.847, 95% CI 0.80–18.51, P = 0.09, respectively). Conclusion: TB incidence in LT recipients is high in this study. Among those post-transplant recipients with long-term immunosuppression, abnormal CT finding and exposure to mTOR inhibitors before liver transplant might be the risk factors for TB.