Immunohistochemical analysis of melanocyte content in different zones of vitiligo lesions using the Melan-A marker

Abstract

Introduction: Occurence of vitiligo lesions is caused by the destruction of melanocytes in affected skin and therefore by the reduction of pigment melanin content. Questions remain about the presence of residual melanocytes in the depigmented skin and optimal methods of their identification. Methods: Skin biopsy samples from 16 patients with non-segmental vitiligo and from 10 healthy volunteers were investigated for Melan-A (À103 clone)+ melanocytes expression by immunohistochemical analysis and for melanin by histochemical studies with section staining by Fontana-Masson method. Results: For some patients including those with long-standing disease (up to 40 years) Melan-A+ cells and melanin granules were detected in depigmented skin as indication that the residual melanocytes are preserved in vitiligo lesions. More than three-fold decrease of Melan-A+ melanocytes amount was revealed in perilesional normally pigmented skin of vitiligo patients (P < 0.001) compared with the skin of healthy volunteers. Clinically intact skin involvement in the pathological process should be taken into consideration if local treatment methods are prescribed. Conclusion: In some vitiligo patients the residual melanocytes are preserved in depigmented skin. Melan-A marker is useful for identification of melanocytes in vitiligo patients' skin.