Abstract
Vitiligo is an autoimmune skin disease characterized by the loss of melanocytes and development of skin depigmentation foci. The exact etiology and pathogenesis of vitiligo are not fully understood, but autoimmune processes have been strongly implicated in the development of the disease. As with other autoimmune diseases, the role of dysfunction of immunosuppressive T-regulatory (Treg) cells in Vitiligo has been actively discussed. It is assumed that reduced immunosuppressive activity and Treg cell infiltration of vitiligo-affected skin lesions play a key role in a breakdown of immune tolerance leading to the development of the disease. However, the phenotypic and functional characteristics of Treg cells in vitiligo remain poorly understood. The aim of this study was to investigate the phenotype of circulating Treg cells in vitiligo. It was found that the proportion of CD4+CD25+ Treg cells, as well as the proportion of CD4+CD25+ Treg cells expressing the immunosuppressive marker CD39 and the cell adhesion and migration marker CD44, were significantly reduced in the peripheral blood of vitiligo patients with active stage of the disease comparing to healthy volunteers. Moreover, we found a decreased proportion of Treg cells possessing CD39+ and CD44+FoxP3+ phenotypes in patients with stable vitiligo. Obtained data suggest that Treg cells play an important role in vitiligo pathogenesis and may indicate a decrease in the functional activity and the recruitment of Treg cells into vitiligo lesions leading to a lack of immunological surveillance. Key words: T regulatory cells, vitiligo, CD39, CD44.