Association between the IL1B (-511), IL1B (+3954), IL1RN (VNTR) Polymorphisms and Graves' Disease Risk: A Meta-Analysis of 11 Case-Control Studies

BACKGROUND: Data on the association between the interleukin-1 (IL-1) gene polymorphisms and Graves' disease (GD) risk were conflicting. A meta-analysis was undertaken to assess this association. METHODS: We searched for case-control studies investigating the association between the IL1B (-511), IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk. We extracted data using standardized forms and calculated odds ratios (OR) with 95% confidence intervals (CI). RESULTS: A total of 11 case-control studies were included in this meta-analysis. Available data indicated that the IL1B (-511) polymorphism was associated with GD risk in the overall populations (Caucasians and Asians) in homozygote model (TT vs. CC, OR = 0.86, 95% CI: 0.76–0.97, P(z) = 0.015), but not in dominant and recessive models (TT+TC vs. CC: OR = 0.95, 95% CI: 0.81–1.12, P(z) = 0.553 and TT vs. TC+CC: OR = 0.82, 95% CI: 0.60–1.12, P(z) = 0.205, respectively). No association between the IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk was found in the overall populations in any of the genetic models. In subgroup analyses according to ethnicity, the IL1B (-511) polymorphism was associated with GD risk in Asians in recessive and homozygote models (TT vs. TC+CC: OR = 0.68, 95% CI: 0.55–0.84, P(z)<0.001 and TT vs. CC: OR = 0.81, 95% CI: 0.70–0.93, P(z) = 0.003, respectively), but not in dominant model (TT+TC vs. CC: OR = 0.92, 95% CI: 0.77–1.11, P(z) = 0.389). No association between the IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk was indicated in Asians, and we found no association between the IL1B (-511), IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk in Caucasians in any of the genetic models. CONCLUSION: The IL1B (-511) polymorphism, but not the IL1B (+3954) and IL1RN (VNTR) polymorphisms was associated with GD risk in Asians. There was no association between these polymorphisms and GD risk in Caucasians.