Macrophage migration inhibitory factor gene polymorphisms (SNP ‐173 G>C and STR‐794 CATT5‐8) confer risk of plaque psoriasis: A case–control study

Abstract Background Macrophage inhibitory factor (MIF) is a pro‐inflammatory cytokine secreted by several cells, including those in the immune system and the skin. The MIF gene contains the SNP ‐173 G> C and STR ‐794 CATT 5‐8 polymorphisms in the promoter region capable of affecting its activity. Our objective was to investigate the MIF polymorphisms as a risk factor for plaque psoriasis (PP) in the Mexican population. Methods We genotyped both MIF polymorphism (rs5844572 and rs755622) in 224 PP patients with a clinical and histopathological diagnosis and 232 control subjects (CS) by the PCR‐RFLP method. MIF serum levels were determined by an ELISA kit. Results We found significant differences in the genotypic and allelic frequencies for the MIF ‐173 G>C polymorphism; carriers of the GC genotype (OR 1.51, 95% CI 1.026–2.228, p = 0.03) and the C allele (OR 1.34, 95% CI 1.005–1.807, p = 0.04) had higher odds to present with PP. Moreover, the 6C haplotype was associated with PP risk (OR 2.10, 95% CI 1.22–3.69, p < 0.01). Also, the ‐173 CC genotype was associated with high MIF serum levels ( p < 0.05). Conclusions The ‐173 GC genotype and the 6C haplotype of the MIF polymorphisms are associated with susceptibility to PP in the Mexican population.