Expression of Epidermal c-Kit+ of Vitiligo Lesions Is Related to Responses to Excimer Laser

BACKGROUND: The survival and growth of melanocytes are controlled by the binding of stem cell factor to its cell surface receptor c-kit+ (CD117). We have observed that c-kit+ melanocytes existed in some lesions of vitiligo, while Melan A+ cells were absent. OBJECTIVE: To verify possible relation between c-kit+ expression and treatment response in non-segmental vitiligo lesions. METHODS: Skin biopsies were done from the center of the 47 lesions from the 47 patients with non-segmental vitiligo. Expression of c-kit+ and Melan A, and amounts of melanin in the epidermis were assessed in each lesion, and treatment responses to excimer laser were evaluated. RESULTS: Thirty-five of the 47 lesions (74.5%) had c-kit+ phenotypes. There was significant difference of c-kit staining value between good responders in 3 months of excimer laser treatment (average of 24 sessions) and the others. CONCLUSION: c-Kit expression in vitiliginous epidermis may be related to better treatment responses to excimer laser.