Correlations between TLR polymorphisms and inflammatory bowel disease: a meta-analysis of 49 case-control studies

Recently, the roles of toll-like receptor (TLR) polymorphisms in inflammatory bowel disease (IBD) were intensively explored, with conflicting results. Therefore, we performed this study to better assess the relationship between TLR polymorphisms and the risk of IBD. Eligible studies were searched in PubMed, Medline, Embase, and Web of Science. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate associations between TLR polymorphisms and IBD. Significant associations with the risk of IBD were detected for the TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, and TLR6 rs5743810 polymorphisms in overall analyses. Further subgroup analyses according to ethnicity of participants revealed that the TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, TLR6 rs5743810, and TLR9 rs352140 polymorphisms were significantly associated with the risk of IBD in Caucasians. Moreover, the TLR4 rs4986790 polymorphism was significantly correlated with the risk of IBD in West Asians, while the TLR9 rs352140 polymorphism was significantly associated with the risk of IBD in Africans. When we stratified available data according to type of disease, we found similar positive results for TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, and TLR6 rs5743810 polymorphisms. Our findings indicate that TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, TLR6 rs5743810, and TLR9 rs352140 polymorphisms may serve as genetic biomarkers of IBD in certain ethnicities. However, further well-designed studies are still warranted to confirm our findings.