Macrophage migration inhibitory factor (MIF) promoter polymorphisms (-794 CATT5-8 and -173 G>C): association with MIF and TNFα in psoriatic arthritis.

Psoriatic arthritis (PsA) is an autoimmune disease with a complex interaction of gene and with a dysregulation of pro-inflammatory cytokine such as Macrophage migration Inhibitory Factor (MIF) and Tumor Necrosis Factor-alpha (TNFα). Two polymorphisms identified in the promoter region of the MIF gene have been described: the STR-794 CATT5-8 (rs5844572) and the SNP-173 G>C (rs755622), which are associated with increased MIF levels in circulation and with autoimmune diseases in several populations. In this case-control study we investigated whether commonly occurring functional MIF polymorphisms are associated with PsA susceptibility and clinical variables as well as with MIF and TNFα serum levels in a Mexican-Mestizo population.