Assessment of tissue FoxP3+, CD4+ and CD8+ T-cells in active and stable nonsegmental vitiligo

Background 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), as well as CD4+ and CD8+ T‐cells in active vs. stable nonsegmental vitiligo. Materials and methods Immunohistochemical double‐staining for expression of CD4+ and CD8+ T‐cells with immunostaining for expression of FoxP3 in lesional, marginal, and nonlesional skin of nonsegmental vitiligo was used to evaluate the abundance of Tregs among CD4+ and CD8+ T‐cells in active and stable cases of vitiligo. Results A significant increase in the number of CD4+ and CD8+ T‐cells and a highly significant reduction in the number of FoxP3‐expressing Tregs were detected in marginal skin in both stable and active vitiligo cases. FoxP3+ cells were decreased in tissue of patients with vitiligo compared with healthy controls. The number of CD8+ T‐cells was increased in the epidermis and dermoepidermal junction (DEJ) in comparison with the number of CD4+ T‐cells. Tregs were mostly present at the DEJ. Conclusion 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.