Interleukin-10 Promoter Gene Polymorphisms and Susceptibility to Asthma: A Meta-Analysis

OBJECTIVE The aim of this study was to explore whether the interleukin (IL)-10 polymorphisms and their haplotypes contribute to asthma susceptibility. METHODS MEDLINE, EMBASE and the COCHRANE library databases were utilized to identify available articles. A meta-analysis was conducted on IL-10 -1082 G/A, -819 C/T, -592 C/A polymorphisms, and their haplotypes and asthma. RESULTS Eleven studies involving 2,215 asthma patients and 2,170 controls were considered in the meta-analysis. The meta-analysis revealed no association between asthma and the IL-10 -1082 G allele [Odds ratio (OR) = 0.87, 95% Confidence interval (CI) = 0.68-1.12, p = 0.28]. However, meta-analysis of the five studies in Hardy-Weinburg equilibrium produced the relationship between the IL-10 -1082 G allele and asthma (OR = 0.71, 95% CI = 0.60-0.83, p<0.0001). Stratification by ethnicity indicated an association between the IL-10 -1082 G allele and asthma in East Asians (OR = 0.74, 95% CI = 0.57-0.96, p = 0.02), but not in West Asians. Furthermore, stratification by age indicated an association between the IL-10 -1082 G allele and asthma in adults and mixed groups (OR = 0.77, 95% CI = 0.62-0.96, p = 0.02; OR = 0.67, 95% CI = 0.49-0.92, p = 0.01). No association was found between asthma and IL-10 -819 C/T and IL-10 -592 C/A polymorphisms and their haplotypes. CONCLUSION The IL-10 -1082 G/A polymorphism confers susceptibility to asthma in East Asians and in adults. However, the IL-10 -819 C/T, -592 C/A polymorphisms and their haplotypes are not associated with asthma.