Association of toll-like receptor 2 gene polymorphism with susceptibility to pulmonary tuberculosis and tuberculous meningitis: a meta-analysis

Background: Toll-like receptor 2 (TLR2) gene plays an important role in the pathogenesis of pulmonary tuberculosis and tuberculous meningitis. The association between TLR2 T597C polymorphism and the susceptibility to pulmonary tuberculosis has been extensively studied. However, the results of these studies remain inconsistent. Therefore, we performed a meta-analysis to evaluate the association between TLR2 T597C polymorphism and the susceptibility to pulmonary tuberculosis and tuberculous meningitis. Methods: PubMed, Embase, CNKI, Wanfang, Weipu databases were searched for case-control studies on TLR2 polymorphisms and the risks of tuberculosis, published up to Nov 31, 2014. To assess the strength of the association between TLR2 polymorphism and pulmonary tuberculosis and tuberculous meningitis, the odds ratios (ORs) with 95% confidence intervals (CIs) were used. The meta-analysis of the associations between the TLR2 T597C polymorphism and pulmonary tuberculosis and tuberculous meningitis were carried out under different genetic models. Results: Fourteen published studies with 4381 cases and 5082 controls were included. Overall, there are significant association between TLR2 T597C polymorphism and the risk of tuberculosis (CC vs. TC OR = 1.26, 95% CI = 1.10-1.43; CC vs. TT OR = 1.20, 95% CI = 1.04-1.38; CC vs. TC+TT OR = 1.23, 95% CI = 1.08-1.39). When stratified by ethnicity, we found a significant association between this polymorphism and tuberculosis risks in Asian (CC vs. TC OR= 1.23, 95% CI = 1.02-1.48; CC vs. TT OR = 1.22, 95% CI = 1.12-1.47; CC vs. TC+TT OR = 1.22, 95% CI = 1.02-1.46) and Caucasians (CC vs. TC OR = 1.31, 95% CI = 1.01-1.62; CC vs. TC+TT OR = 1.24, 95% CI = 1.01-1.52). We also found significant the association between this polymorphism and pulmonary tuberculosis (CC vs. TC OR = 1.16, 95% CI = 1.01-1.34) and the tuberculous meningitis (CC vs. TC OR = 3.16, 95% CI = 2.00-5.00; CC vs. TT OR = 3.56, 95% CI = 2.27-5.58; CC vs. TC+TT OR = 3.37, 95% CI = 2.19-5.19; CC+TC vs. TT OR = 1.36, 95% CI = 1.05-1.77; C vs. T OR = 1.52, 95% CI = 1.25-1.85), respectively. Conclusions: TLR2 T597C polymorphism associated with the susceptibility to pulmonary tuberculosis and tuberculous meningitis.