IMMUNOHISTOCHEMICAL EXPRESSION OF MELAN A AND ITS RELATION TO EXPRESSION OF CXCR3 IN VITILIGO LESIONS

Abstract

Background: Vitiligo is an acquired pigmentary disorder due to loss or destruction of melanocytes from the epidermis. The question about the presence of residual melanocytes in the depigmented skin remains and accurate methods of their identification are considered. Objective: This study aimed to search about the presence of residual melanocytes in the skin of vitiligo patients and if there is a relation between destruction of melanocytes and presence of inflammatory cells mainly T-lymphocytes. Patients and Methods: This study was conducted on 30 patients with vitiligo (localized and generalized) together with 10 healthy volunteers were investigated for Melan-A (А103 clone) expression by immunohistochemical analysis and for CXCR3 antibody. Results: Melan-A+ cells were detected in depigmented skin as indication that the residual melanocytes are preserved in vitiligo lesions. Decrease of Melan-A+ melanocytes amount was revealed in perilesional normally pigmented skin of vitiligo patients (P < 0.01) compared with the skin of healthy volunteers. Also this study found significantly increased number of CXCR3-expressing cells in the dermis of vitiligo lesions (depimented skin) in comparison to healthy controls and those cells were mainly lymphocytes Conclusion: Melan-A marker is useful not only for identifying melanocytes in vitiligo patients’ skin but also for estimating their content in different zones of the vitiligo lesions. Clinically intact skin involvement in the pathological process should be taken into consideration if local treatment methods are recomended. CXCR3 and its ligands play role in the pathogenesis of vitiligo. So, blocking T-cell recruitment by blocking CXCR3 and its ligand chemotactic mechanism may present a new and effective therapy for vitiligo.