Il6 174 G/C Polymorphism in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

The results of previous studies on the association between il-6-174g/c (rs1800795) polymorphism and inflammatory bowel disease (ibd), including crohn’s disease (cd) and ulcerative colitis (uc) are not consistent. the present meta-analysis has pooled all eligible studies to understand the relation between this gene polymorphism and ibd risk. a structured search of medline, embase, and scopus databases were performed to identify all eligible studies published before june 2017. odds ratio (or) and 95% confidence intervals (cis) were assessed applying fixed- or random-effect models to evaluate the strength of association in recessive model, dominant model, allelic model, heterozygote contrast, and homozygotes contrast. a sum of 9 articles with 1524 ibd cases and 1586 healthy subjects were included in this study. no significant association between the il-6 -174 g/c polymorphism and overall ibd susceptibility in any tested genetic model was found. moreover, in the subgroup analysis based on subtypes, the associations between the il-6 174-g/c polymorphism and cd and uc missed statistical significance. the current meta-analysis suggests that the il-6-174 g/c polymorphism is not associated with ibd susceptibility. further and comprehensive studies are necessary to warrant this result.