Polymorphisms of Toll-Like Receptor 4 as a Risk Factor for Periodontitis: Meta-Analysis

Background. Toll-like receptors play an important role in the recognition of periopathogens. There are widely known polymorphisms of these receptors that may alter host susceptibility to periodontitis. Objectives. Evaluating the association of TLR4 polymorphisms (Asp299 and Thr399Ile) with the occurrence of periodontitis and its two clinical types: chronic (CP) and aggressive (AgP) among Caucasians. Material and Methods. A review of 4 electronic databases was made to identify studies that match the inclusion criteria for the meta-analysis and were published up to December 31, 2013. Results. Fifteen studies met the inclusion criteria. For Asp299Gly polymorphism 1621 patients with periodontitis (1148 with CP and 473 with AgP) and 1755 individuals without clinical signs of periodontitis were included in the meta-analysis. The occurrence of polymorphism The399Ile was evaluated among 1522 patients with periodontitis (1017 with CP and 505 with AgP) and 1461 subjects in the control group. The pooled OR with a random effects model for the Asp299Gly and chronic periodontitis was 1.35 (95% CI: 1.02-1.8, p = 0.038), indicating a possible association between this polymorphism and CP. Other published meta-analyzes showed no significant association between single nucleotide polymorphisms of TLR4 and periodontitis nor its clinical types. No publication bias was reported. Conclusions. Our meta-analysis showed statistically significant association between TLR4 Asp299Gly allele and increased susceptibility to chronic periodontitis.