Background: Vitiligo is an acquired idiopathic and polygenic disorder with progressive depigmentation of circumscribed patches. Its exact pathogenesis is unknown. The CD4 gene plays an important role in the cell-mediated immune response and its association with type 1 diabetes mellitus, which is an autoimmune disease, has been previously reported.
Methods: Based on the assumption that autoimmunity is also involved in vitiligo, the CD4 gene was selected for study using a candidate gene approach. The pyrimidine-rich pentanucleotide repeat length polymorphism located in the promoter of the gene was studied. We screened 144 unrelated Iranian patients with vitiligo and 144 healthy matched controls by PCR.
Results: The CD4*A4 allele has a susceptibility association with the development of vitiligo in the Iranian population (OR = 1.68, 95% CI 1.18-2.42; P < 0.01, P(c) = 0.02). When we compared CD4*A4-containing genotypes in the case and control groups, even more significant positive association was identified (OR = 2.02, 95% CI 1.26-3.22; P < 0.01 and P(c) < 0.01). The CD4 gene polymorphism has a modest association with the development of vitiligo in Iranian patients.