Study of interleukin-17 gene polymorphism and susceptibility to vitiligo in a sample of the Egyptian population

Background Vitiligo is a common, acquired disorder resulting in depigmentation due to loss of functional melanocytes. The role of the immune system in the pathogenesis of the disease has been studied and hypothesized shifting toward Th17 response with the production of various inflammatory cytokines including interleukin (IL)-17. IL-17 gene polymorphism has been associated with various autoimmune disorders but, to our knowledge, has not been studied before in vitiligo. Objective To investigate the association of IL-17 gene polymorphism and susceptibility to vitiligo. Patients and methods IL-17 genotyping was performed for 75 patients with vitiligo and 93 healthy controls using the restriction fragment length polymorphism PCR technique. Serum level of IL-17 was also estimated in 30 of these patients and 40 controls using enzyme-linked immunosorbent assay technique. Results No significant difference was found between the different genotypes of IL-17 gene (GG, AG, and AA) in vitiligo patients and controls (P =0.250, 0.102, and 0.128, respectively). Moreover, we did not find any significant relation between IL-17 gene polymorphism and any of the clinical aspects of the disease. However, a significant difference was found between serum levels of IL-17 in patients and controls (P = 0.003) with a significant negative correlation with age (r = – 0.446, P = 0.013) and duration of disease (r = – 0.439, P = 0.015). Conclusion IL-17 gene polymorphism is not associated with an increased susceptibility to vitiligo, although IL-17 plays an important role in the pathogenesis of the disease.