LAUSR

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 CATT5-8 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.