The exact etiology of vitiligo remains obscure. Studies have indicated a role for cellular immunity in the pathogenesis of vitiligo. The aim of this study is to assess tissue FOXP3+ natural regulatory T-cells (Tregs) in active vs. stable nonsegmental vitiligo. Immunohistochemical staining for expression of FoxP3 in lesional, marginal, and nonlesional skin of nonsegmental vitiligo was used to evaluate the abundance of Tregs in active and stable cases of vitiligo. Reduction in the number of FOXP3-expressing Tregs was detected in marginal skin in both stable and active vitiligo cases. The results revealed that FOXP3+ T-cells were lowest in marginal skin of active cases in comparison with lesional and nonlesional skin of the same group. Tregs were lower in marginal and nonlesional skin of stable vitiligo compared with lesional skin of the same group. Tregs were mostly present at the DEJ and upper dermis. The reduction in the number of FOXP3+ cells in the marginal skin suggests that this is the site where regulatory activity is needed to suppress the activity of helper and cytotoxic T-cells that are actively contributing to depigmentation. |
