Association between polymorphisms in the promoter region of interleukin-10 and susceptibility to inflammatory bowel disease.

The aim of this study was to assess the association of polymorphisms in the promoter region of the IL-10 gene with the risk of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Fifteen studies (3,693 cases and 4,574 controls) were included in a meta-analysis of association between IL-10 -1082G/A, -819C/T and -592C/A polymorphisms, and IBD, CD and UC using allele contrast and the recessive, dominant, and additive models. Hardy-Weinberg equilibrium was confirmed for each study. Heterogeneity and study quality were investigated using stratification analyses and sensitivity analyses. Polymorphism -1082G/A showed significant association with CD, with odds ratios (ORs) for the GG + GA genotype and GG versus AA genotype of 1.278 (1.004-1.627) and 1.238 (1.027-1.492) in all subjects. Significant associations were found in the Caucasian subgroup using the allele contrast, dominant, and additive models. C-allele carriers of the -819C/T polymorphism were at increased risk of IBD (OR 1.093, 95% CI 1.004-1.190). Association with the -819C/T polymorphism was also found in Caucasians with CD (C vs. T: OR 1.104, 95% CI 1.010-1.206; CC + CT vs. TT: OR 1.328, 95% CI 1.006-1.754; CC vs. TT: OR 1.339, 95% CI 1.008-1.778), and with UC (CC vs. CT + TT: OR 1.188, 95% CI 1.019-1.385). No significant association was found between the -592C/A polymorphism and IBD, CD or UC. In conclusion, the meta-analysis demonstrated clear association between the IL-10 polymorphisms -1082G/A and -819C/T and the risk of IBD.