Glabrous lesional stem cells differentiated into functional melanocytes: new hope for repigmentation.

BACKGROUND: Vitiligo is characterized by the loss of pigment-producing cells, melanocytes and one of the important goals of treatment is replenishing the melanocytes from existing reservoirs. Reservoir for melanocyte stem cell has been reported to be present in the skin hair follicles, but glabrous skin does not have hair follicles. Therefore, repigmentation of glabrous lesional skin is very difficult and almost rare. There is no explanation for melanocyte reservoir in the glabrous lesional skin of vitiligo patients.

OBJECTIVE: This study is designed to check the glabrous lesional skin for the presence of stem cells as source of melanocytes for repigmentation.

METHODS: Skin grafts were collected from glabrous lesional skin of vitiligo patients. Immunohistochemistry of glabrous lesional skin was performed to check for the presence of stem cells. These glabrous lesional stem cells were isolated, cultured and characterized. After characterization, glabrous lesional stem cells were differentiated into melanocytes.

RESULTS: Our results demonstrate that NGFRp75-positive stem cells are present in the glabrous lesional skin of vitiligo patients and can be differentiated into melanocytes. These dermal stem cells showed self-renewal capacity and were capable of differentiating into melanocytes which are required for the repigmentation.

CONCLUSION: Presence of stem cells in the glabrous lesional skin which are capable of self-renewal and differentiating into melanocytes gives new hope for vitiligo patients having lesion on the glabrous skin. However, still repigmentation of glabrous lesional skin is very difficult and rare with current available treatments. This clearly means that treatments available till date are not effective enough to activate these dermal stem cells differentiation and their migration to the lesional epidermis. Stimulating these stem cells to differentiate into melanocytes and migrate to lesional epidermis can be ideal for repigmentation of the glabrous lesions.