Methods paperAssociation of the macrophage migration inhibitory factor gene − 173G/C polymorphism with inflammatory bowel disease: A meta-analysis of 4296 subjects

•We performed a meta-analysis to derive a more precise estimation of the relationship.•Our study has the potential to detect small effects in genetic association studies.•Our study suggests that MIF gene polymorphism is associated with IBD risk.

A variety of epidemiologic studies have focused on the association between macrophage migration inhibitory factor (MIF) gene − 173G/C polymorphism and inflammatory bowel disease (IBD). However, results in different studies have been inconsistent. In order to derive a more precise estimation of the associations, we performed this meta-analysis and systematic searches of electronic databases PubMed and Web of Science (up to April 30, 2013). Based on our search criteria, a total of seven eligible studies concerning the MIF − 173G/C polymorphism and IBD risk were included in the final meta-analysis, comprising 2162 IBD cases and 2134 controls. Significant association was found between MIF − 173G/C polymorphism and the risk of IBD when all studies were pooled into the meta-analysis (for C allele vs. G allele: OR = 1.25, 95% CI = 1.12-1.41, p = 0.000; for C/C vs. G/G: OR = 1.71, 95% CI = 1.23-2.39, p = 0.002; for C/C + G/C vs. G/G: OR = 1.24, 95% CI = 1.09-1.42, p = 0.002; for C/C vs. G/C + G/G: OR = 1.67, 95% CI = 1.20-2.33, p = 0.002). Heterogeneity and publication bias did not exist in the overall comparisons. The present meta-analysis suggests an association between the MIF − 173G/C polymorphism and IBD risk. However, due to few studies and the selection bias existed in some studies, the results should be interpreted with caution.