Association between the IL1B, IL1RN polymorphisms and COPD risk: A meta-analysis

The interleukin-1 (IL-1) gene polymorphisms have been implicated in chronic obstructive pulmonary disease (COPD) risk, but results are controversial. We aimed to conduct a meta-analysis to address this issue. Odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of the association. The meta-analysis revealed no association between the IL1B (-511), (-31), (+3954) polymorphisms and COPD risk. However, stratification by ethnicity indicated that the T allele carriers of the IL1B (-511) polymorphism and the C allele carriers of the IL1B (-31) variant were associated with an increased risk for developing COPD in East Asians (OR = 1.61, 95% CI: 1.13-2.31, Pz = 0.009 and OR = 1.55, 95% CI: 1.14-2.11, Pz = 0.006, respectively). The meta-analysis revealed a significant association between the IL1RN (VNTR) polymorphism and COPD risk in all study subjects and East Asians under homozygote model (22 vs. LL: OR = 3.16, 95% CI: 1.23-8.13, Pz = 0.017 and OR = 3.20, 95% CI: 1.13-9.12, Pz = 0.029, respectively). Our meta-analysis suggests that the IL1B (-511), (-31) and IL1RN (VNTR) polymorphisms are associated with COPD risk in East Asians. There is no association between the IL1B (+3954) polymorphism and COPD risk. Further studies should be performed in other ethnic groups besides East Asians.