Pre-transplant risk factors for tuberculosis after kidney transplant in an intermediate burden area

OBJECTIVE: To examine pre-transplant risk factors for the development of post-kidney transplant tuberculosis (TB) in an intermediate TB burden country, as this is important for early detection and prophylaxis to prevent post-transplant TB. DESIGN: A retrospective, longitudinal cohort study of 1097 kidney transplant patients was performed at the Severance Hospital, Seoul, South Korea, between January 2000 and March 2010. The standardised incidence ratio (SIR) of post-transplant TB compared to the general population was calculated and pre-transplant risk factors were analysed. RESULTS: Among the 1097 kidney transplant patients, 2.1% (23/1097) developed post-transplant TB, with an incidence of 445.2 cases per 100 000 patients per year. The SIR of TB in kidney transplant patients compared with the general population was 4.26 (95%CI 2.6-6.45). A positive tuberculin skin test (TST; RR 3.54, 95%CI 1.13-11.11, P = 0.03) and previously healed TB on chest radiograph (CXR; RR 8.71, 95%CI 1.00-75.84, P = 0.05) were significant pre-transplant risk factors for post-transplant TB on multivariate analysis. CONCLUSION: The incidence of TB in kidney transplant patients was higher than in the general population. Positive TST results and previously healed TB lesions visible on pre-transplant CXR were significant pretransplant risk factors for post-kidney transplant TB.