Exploring the role of Interleukin-16 genetic variation and expression in vitiligo

Vitiligo is a multifactorial melanocyte disease caused by immune-mediated destruction. Inflammatory cytokines are central to vitiligo pathogenesis. Interleukin-16 (IL-16) is a pro-inflammatory cytokine implicated in the recruitment and activation of T-cells (CD4+), indicating that it may play a role in autoimmune inflammation. Nevertheless, the IL-16 expression and its genetic variants in vitiligo are poorly understood. This study involved 100 patients diagnosed with vitiligo and 50 age and gender harmonized controls. TaqMan assays were used to genotype the rs4072111 polymorphism, and qRT-PCR was employed to determine the IL-16 relative expression. VIDA and VASI scores were used to assess clinical activity and severity. Patients had a higher prevalence of C/T, T/T genotypes, and T allele than controls. IL-16 expression was notably higher in patients. The increased level of relative expression was associated with active disease. This study indicates that IL-16 rs4072111 polymorphism and increased IL-16 gene expression were significantly associated with vitiligo. Higher IL-16 expression was also linked to greater disease activity. These findings emphasize that IL-16 may serve as a promising biomarker for disease susceptibility and activity, although further validation in larger and more diverse populations is required.