Lack of association between Toll-like receptor 4 gene Asp299Gly and Thr399Ile polymorphisms and tuberculosis susceptibility: a meta-analysis.

OBJECTIVE

Toll-like receptor 4 (TLR4) plays a vital role in immunity to tubercle bacillus and its gene polymorphisms are supposed to affect tuberculosis susceptibility in some rather than all studies. Then, we integrated published data and performed a comprehensive meta-analysis to get more reliable estimations for the strength of associations between TLR4 gene polymorphisms and the risk of tuberculosis.

METHODS

We systematically searched the electronic PubMed database for research articles about TLR4 gene polymorphisms and tuberculosis up to February 2012. Revman 5.0 software was adopted to conduct the meta-analysis. Crude odds ratio (ORs) and 95% confidence intervals (95% CIs) were calculated by either fixed-effects model or random-effects model.

RESULTS

Finally, six case-control studies were identified, involving 1587 controls and 2110 patients. Overall, no significant associations were found between TLR4 gene Asp299Gly polymorphism and tuberculosis in the codominant models (GG vs AA: OR=1.56, 95% CI=0.76-3.21, P=0.23; GA vs AA: OR=1.01, 95% CI=0.84-1.23, P=0.89), the dominant model (GG+GA vs AA: OR=1.04, 95% CI=0.80-1.35, P=0.75), the recessive model (GG vs GA+AA: OR=1.55, 95% CI=0.75-3.19, P=0.24) and the allele model (G vs A: OR=1.06, 95% CI=0.81-1.40, P=0.66). Similarly, no significant associations between TLR4 gene Thr399Ile and tuberculosis were observed (all P>0.05).

CONCLUSIONS

The present meta-analysis suggests that TLR4 gene Asp299Gly and Thr399Ile polymorphisms are not associated with the susceptibility of tuberculosis.