Polymorphisms in the SLC11A1 gene and tuberculosis risk: a meta-analysis update

BACKGROUND: Polymorphisms in SLC11A1 gene have been extensively studied for an association with tuberculosis (TB); however, results from replication studies have been inconsistent. OBJECTIVE: To comprehensively evaluate the genetic risk of polymorphisms (D543N, 3'UTR TGTG ins/del, INT4, [GT]n) in the SLC11A1 gene for TB. METHODS: A meta-analysis was carried out to analyse the association between SLC11A1 polymorphisms and TB risk. RESULTS: A total of 82 case-control studies in 35 articles were included in the meta-analysis. The results showed that these four polymorphisms were associated with an increased risk of TB (D543N OR 1.31, 95%CI 1.11-1.55; 3'UTR TGTG ins/del OR 1.45, 95%CI 1.25-1.68; INT4 OR 1.27, 95%CI 1.09-1.49; [GT]n OR 1.35, 95%CI 1.14-1.61). In further stratified analyses by ethnicity and TB forms, significant increased risks were found in subgroups of Asians and in pulmonary TB (PTB) for all four polymorphisms, while an increased risk of extra-pulmonary TB (EPTB) was found for D543N polymorphism. CONCLUSIONS: This meta-analysis suggests that polymorphisms in the SLC11A1 gene contribute to TB (both PTB and EPTB), particularly in Asians.