Toll-like receptor 4 polymorphisms and susceptibility to multiple autoimmune diseases: Evidence based on pooled analysis

Abstract

Background: Toll-like receptor 4 (TLR4) is known to activate the nuclear factor κB (NF-κB) and subsequent gene expression such as cytokines and adhesion molecules. That may subsequently reduce the risk of autoimmune diseases (ADs). However, the results of molecular epidemiological studies remain inconsistent. Material and methods: The PubMed, Embase, CNKI databases were searched for all articles available. The OR corresponding to the 95% confidence interval (95% CI) was used to assess the association between TLR4 polymorphisms and the risk of ADs. Results: The TLR4 Asp299Gly and TLR4 Thr399Ile polymorphisms were not associated significantly with a risk of ADs (Asp299Gly: OR = 0.86, 95% CI: 0.74-1.00 for G vs. A and OR = 0.87, 95% CI: 0.74-1.01 for AG/GG vs. AA, respectively; Thr399Ile: OR = 0.77, 95% CI: 0.57-1.05 for T vs. C and OR = 0.79, 95% CI: 0.58-1.09 for TT/CT vs. CC, respectively). Conclusions: This meta-analysis suggested that TLR4 Asp299Gly and TLR4 Thr399Ile polymorphisms were not involved in the development of ADs. However, well-designed studies with a larger sample size should be conducted to confirm this result.