Association between Gene Polymorphisms of T Cell Immunoglobulin Domain and Mucin Domain-3 and Risk of Asthma: A Systematic Review and Meta-analysis

Previous studies have reported that T cell immunoglobulin domain and mucin domain-3 (TIM-3) 574T>G and 1516G>T are associated with the risk of asthma. However, the results are inconsistent due to the small sample size and varied age in studies. We performed this meta-analysis to systematically evaluated the effect of TIM-3 574T>G and 1516G>T genetic polymorphisms on asthma. Eligible articles that reported an association between TIM-3 574T>G and 1516G>T genetic polymorphisms and asthma were searched in PubMed, Medline, EMBASE, Google Scholar, and China National Knowledge Infrastructure up to April 2020. Random or fixed-effects models were used to calculate the summary of odds ratios (ORs) and 95% confidence intervals (CIs) to detect any potential associations between TIM-3 genetic polymorphisms and asthma. Subgroup and sensitivity analyses were performed to assess the potential sources of heterogeneity and the robustness of the pooled estimation. Publication bias was analyzed using the Egger test. A total of 11 case-control studies including 2077 asthma patients and 2122 control subjects were finally analyzed (published data form 2004-2018). The pooled results indicated that TIM-3 574T>G genetic polymorphisms were significantly associated with an increased risk of asthma under the dominant model (GG vs. GT +TT: ORs=2.26, 95% CI 1.09-4.69) and allele model (G vs T: ORs=2.60, 95% CI 1.20-5.64). However, no significant associations between TIM-3 1516G>T genetic polymorphisms with asthma in any model was found. No evidence of publication bias was observed.  Our study indicates that TIM-3 574T>G genetic polymorphisms were associated with increased risk of asthma and the TIM-3 1516G>T genetic polymorphisms may not be correlated with asthma.