An immunohistochemical study of depigmented skin of vitiligo patients

Resumo

Immunohistochemical analysis was used to study depigmented areas, macular depigmentation, and perimacular areas of the skin of vitiligo patients. It has been shown that cells containing the melanocytic cell marker TRP1 are located in both macular and perimacular areas. Within the macula of depigmentation, all TRP1-positive cells are in close contact with the base membrane. In perimacular areas, many TRP1-positive cells that have lost contact with the base membrane are located in deep layers of epidermis. About 92% of TRP1-positive perimacular cells were also vimentin-positive. Vimentin-positive cells were numerous in perimacular areas, but missing in the macula of depigmentation. Dense groups of cells that were immunopositive for the transcription factor Snail, an inducer of epithelial mesenchymal transition, were localized in perimacular areas in close proximity to the macula of the depigmentation border. Within the macula of depigmentation, such cells were extremely rare. It seems reasonable that an intense process similar to the epithelial mesenchymal transition may be the cause of melanocyte death in the perimacular area and, thus, prevents repigmentation of depigmented areas.