Association of the macrophage migration inhibitory factor gene--173G/C polymorphism with inflammatory bowel disease: a meta-analysis of 4296 subjects.

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.