Interleukin-17F 7488T/C polymorphism is associated with protection against asthma: a meta-analysis.

The association between interleukin-17F (IL-17F) 7488T/C polymorphism and asthma risk is conflicting. This study conducted a meta-analysis by pooling all available data to make a more precise estimation of the association. Electronic databases PubMed, EMBASE, and China National Knowledge Infrastructure were searched to identify all eligible studies assessing the association between IL-17F 7488T/C polymorphism and asthma risk. The pooled odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) were calculated. A total of five case-control studies with 1445 cases and 1608 controls were included. Overall, the pooled ORs showed that the IL-17F 7488T/C polymorphism was inversely associated with risk of asthma (OR=0.29, 95% CI=[0.12, 0.70]) using recessive genetic model. Furthermore, this association was found to be exclusive to Asians (OR=0.31, 95% CI= [0.12, 0.84]). Sensitivity analysis by omission of single study in turn showed similar results. In conclusion, the present meta-analysis suggested that homozygote of IL-17F 7488T/C variant could protect against asthma in Asians. However, more studies conducted in different ethnic groups with large sample size are warranted to validate the precise association.