Association between Interleukin-4 Receptor α Chain (IL4RA) I50V and Q551R Polymorphisms and Asthma Risk: An Update Meta-Analysis

BackgroundThe associations between the interleukin-4 receptor α chain (IL4RA) I50V and Q551R polymorphisms and asthma risk remained controversial.MethodsWe searched the Pubmed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases for studies published before February 2013. The strengths of the associations were calculated using odds ratios (ORs) with 95% confidence intervals (CIs).ResultsA total of 50 studies were included in this meta-analysis. There was a significant association between the IL4RA I50V polymorphism and asthma risk in a dominant genetic model (OR = 1.13, 95% CI 1.04–1.23, P = 0.005). The IL4RA Q551R polymorphism was associated with a significantly elevated asthma risk in a recessive genetic model (OR = 1.46, 95% CI 1.22–1.75, PIL4RA I50V polymorphism was significantly associated with asthma risk in Asians (OR = 1.72, 95% CI 1.31–2.25, PP = 0.005), and atopic asthma risk (OR = 1.88, 95% CI 1.27–2.79, P = 0.002).ConclusionsThe results of this meta-analysis suggested that the IL4RA I50V and Q551R polymorphisms may be risk factors for developing asthma.