Confirmation of association of the macrophage migration inhibitory factor gene with systemic sclerosis in a large European population

Objectives. The aim of this study was to confirm the implication of macrophage migration inhibitory factor (MIF) gene in SSc susceptibility or clinical phenotypes in a large European population. Methods. A total of 3800 SSc patients and 4282 healthy controls of white Caucasian ancestry from eight different European countries were included in the study. The MIF −173 single nucleotide polymorphism (SNP) was selected as genetic marker and genotyped using Taqman 5′ allelic discrimination assay. Results. The MIF −173 SNP showed association with SSc [P = 0.04, odds ratio (OR) = 1.10, 95% CI 1.00, 1.19]. Analysis of the MIF −173 polymorphism according to SSc clinical phenotype revealed that the frequency of the −173*C allele was significantly higher in the dcSSc group compared with controls (P = 5.30E-03, OR = 1.21, 95% CI 1.07, 1.38). Conversely, the frequency of the MIF −173*C allele was significantly underrepresented in the lcSSc group compared with dcSSc patients, supporting previous findings [(P = 0.04, OR = 0.86, 95% CI 0.75, 0.99); meta-analysis including previous results (P = 0.005, OR = 0.83, 95% CI 0.73, 0.94)]. Conclusion. Our results confirm the role of MIF −173 promoter polymorphism in SSc, and provide evidence of a strong association with the dcSSc subgroup of patients. Hence, the MIF −173 variant is confirmed as a promising clinical phenotype genetic marker.