The -33C/T polymorphism in the interleukin 4 gene is associated with asthma risk: A meta-analysis

Objective: the association between the interleukin 4 (il-4) gene -33c/t polymorphism and asthma risk is a subject of debate. we conducted a meta-analysis to evaluate the association between this polymorphism and asthma susceptibility. materials and methods: a systematic search of electronic databases (pubmed,embase,wanfang,china national knowledge infrastructure,and weipu) was performed,and 18 studies involving 5523 cases and 5618 controls were identified. ors with 95% cis were used to assess the strength of association. results: a significant association between the -33c/t polymorphism and asthma susceptibility was observed for tt vs ct + cc (or,1.16; 95% ci,1.05-1.28; p=.005). in the subgroup analysis by race,a significant association was found among whites (or,1.71; 95% ci,1.14-2.57; p=.01) and asians (or,1.14; 95% ci,1.01-1.28; p=.04) but not among african americans. in the subgroup analysis by atopic status,no significant association was found among atopic asthma patients (or,1.05; 95% ci,0.89-1.24; p=.54) or nonatopic asthma patients (or,1.16; 95% ci,0.81-1.67; p=.42). in the age-stratified analysis,an increased asthma risk was found in children (or,1.28; 95% ci,1.01-1.63; p=.04) but not in adults. conclusions: the results of this meta-analysis suggest that the il-4 -33c/t polymorphism is a risk factor for asthma. © 2014 esmon publicidad.