Abstract
Although genetics plays an essential role in the pathogenesis of vitiligo, vitiligo pathogenesis is still unclear. Our aim was to investigate the role of IFN-gamma expression and polymorphism in vitiligo susceptibility and whether intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor (TNF)-alpha, and TNF-beta play a role in vitiligo pathogenesis as important inflammatory parameters. Eighty-five patients with vitiligo and 90 controls were investigated for IFN-gamma gene expression by quantitative real-time PCR and genotyped for IFN-gamma +874T/A (rs2430561) and IFN-gamma +2109A/G (rs1861494) gene polymorphisms by sequence-specific primer (SSP)-PCR and PCR-restriction fragment length polymorphism (RFLP), respectively. Serum levels of inflammatory parameters were measured using ELISA. Frequencies of the +874 TT genotype and T allele were significantly higher in patients with active vitiligo than in stable patients (P = 0.01 and 0.03, respectively). Calculation of odds ratio suggested a 1.7-fold increased risk of vitiligo in individuals having the TA haplotype. We observed overexpression of IFN-gamma mRNA with elevated serum levels of IFN-gamma, ICAM-1, TNF-alpha, and TNF-beta in patients with vitiligo when compared with the control group (P = 0.001, for all). In addition, these levels were elevated in patients with active vitiligo compared with stable patients with vitiligo (P = 0.008, 0.006, 0.01, 0.01, and 0.03, respectively), which suggests the involvement of these cytokines in disease activity. In conclusion, IFN-gamma is a promising immunological marker in vitiligo pathogenesis.