LAUSR

INTRODUCTION Tuberculosis (TB) is considered as a serious complication for organ transplant recipients; therefore, the detection and appropriate treatment of latent infection are recommended for preventing active TB infections in the future. The objective of this review is to conduct a systematic review and meta-analysis of studies assessing the prevalence of latent TB infection (LTBI) in transplant candidates. METHODS Electronic databases, including MEDLINE (via PubMed), SCOPUS were searched until 30 June 2017. The prevalence of LTBI was estimated using the random effects meta-analysis. Heterogeneity was evaluated by subgroup analysis. Data were analyzed by STATA version 14. RESULTS The pooled prevalence of LTBI based on tuberculin skin test (TST) in different transplant types was as follows: liver 24% (14%-33%, 95% CI), lung 22% (18%-26%), renal 21% (16%-27%, 95% CI) and hematopoietic stem cell transplantation (HCT) 14% (9%-19%). The prevalence of LTBI based on Interferon Gamma Release Assay (IGRA) tests in renal transplant candidates was 31% (95% CI; 25-37%), which was much higher than the prevalence of LTBI in liver transplant candidates (25%, 95% CI; 17-33%) and HCT transplant candidates (13%, 95% CI; 10-16%) and there was statistically significant differences between them. The pooled prevalence of indeterminate results based on IGRAs test in different transplant types was as follows: renal 6% (4%-8%, 95% CI) and liver 12% (2%-21%, 95% CI). Subgroup analysis revealed that there were statistically significant differences between the overall prevalence of indeterminate results by using IGRA tests in liver transplant candidates (12%, 95% CI; 2-21%) and renal transplant candidates (6%, 95% CI; 4-8%). The pooled prevalence of post-transplant TB was 2% (1%-2%, 95% CI) and its occurrence was more common in renal recipients (4% (2%-7%, 95% CI)) than in the liver transplant patients (1% (0%-2%, 95% CI)). The prevalence of LTBI in the subgroup (i.e. the patients' mean age was <50 years) was significantly higher than the prevalence of LTBI by using TST/IGRAs in the other subgroup (i.e. the patients' mean age was ≥50 years). CONCLUSION Our study suggests fair overall agreement between IGRAs and TST in patients requiring liver and HCT transplantation, while a superiority of IGRAs over TST in patients requiring renal transplantation was seen.