Association between functional promoter polymorphisms of macrophage migration inhibitory factor (MIF) gene and ulcerative colitis in Japan

Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. Two functional polymorphisms were identified in the promoter region of MIF gene. We attempted to clarify the associations between these polymorphisms and ulcerative colitis (UC). The study was performed in 111 patients with UC and 209 subjects without UC. We employed the PCR–SSCP method to detect gene polymorphisms. Overall, 5/5-CATT genotype was a decreased risk for the development of UC (OR, 0.51; 95% CI, 0.26–0.99). In addition, 7/7-CATT genotype was significantly associated with chronic continuous phenotype and distal colitis phenotype (OR, 5.49; 95% CI, 1.19–25.3, and OR, 6.10; 95% CI, 1.32–28.2, respectively), whereas 5/5-CATT genotype had an inhibitory effect on the development of UC after 20 years of age (OR, 0.33; 95% CI, 0.14–0.82). On the other hand, G-173C polymorphism did not affect the susceptibility to and the phenotypes of UC. Our results suggested that tetranucleotide CATT repeat of MIF gene promoter may be associated with the development of UC and the severity of inflammation in patients with UC.