Association of macrophage migration inhibitory factor gene polymorphisms with Behçet's disease in a Han Chinese population

Objective: To examine whether polymorphisms of the macrophage migration inhibitory factor (MIF) gene are associated with Behçet's disease (BD) in a Han Chinese population.

Design: Case-control study.

Participants: A total of 600 patients with BD and 600 age-, sex-, and ethnically matched healthy controls were enrolled.

Methods: Two single nucleotide polymorphisms (SNPs), rs755622 and rs2096525, were genotyped using a polymerase chain reaction (PCR) restriction fragment length polymorphism assay. Allele and genotype frequencies were compared between patients and controls using the chi-square test. The expression of MIF was examined by real-time PCR.

Main outcome measures: Association of SNPs in MIF with BD.

Results: Significantly decreased frequencies of the rs755622 genotype GG and G allele were found in patients with BD compared with controls. The frequencies of the genotype TT and T allele of the SNP rs2096525 were significantly lower in patients with BD compared with controls. Stratification analysis showed that the frequencies of rs755622 genotype GG in the oral aphthae, genital ulceration, or hypopyon subgroups were significantly decreased compared with controls (all P(c) < 0.05). A significantly lower frequency of the G allele of rs755622 was observed in the oral aphthae, genital ulceration, hypopyon, and arthritis subgroups compared with controls (P(c) < 0.05). The frequencies of the rs2096525 genotype TT and T alleles were also decreased in the oral aphthae, genital ulceration, hypopyon, and skin lesion subgroups compared with the controls (P(c) < 0.01). The results also showed that the expression of MIF mRNA in individuals carrying the CC genotype of rs755622 was 1.78- and 1.92-fold higher than in those carrying the GC or GG genotype.

Conclusions: This study identified a strong association of the 2 SNPs, rs755622 and rs2096525, in the MIF gene with BD and suggests that the involvement of MIF in BD may be through regulation of its mRNA expression.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.