Ratio of size of recipient and donor areas in treatment of vitiligo by autologous cultured melanocyte transplantation

Summary Background  Autologous melanocytes can be expanded in vitro, allowing the treatment of large lesions of vitiligo in one session. Theoretically, this procedure could provide a higher donor/recipient size ratio (DR ratio) compared with that in noncultured cell transplantation (with a DR ratio < 1 : 10). However, the exact DR ratio obtained from this procedure has not been reported. Objectives  To study whether transplantation of cultured pure melanocytes at a high DR ratio is as efficient as that at a low DR ratio. Methods  One hundred and two patients with vitiligo were treated by transplantation of cultured pure melanocytes and were divided into two groups: a low DR ratio group, including patients with DR ratio ≤ 1 : 10 (mean 1 : 8, 35 cases) and a high DR ratio group with DR ratio > 1 : 10 (mean 1 : 27, 67 cases). The extent of repigmentation between these two groups was compared. Results  There was no significant difference in repigmentation between the low DR ratio group (mean ± SD 77·4 ± 22·5%) and the high DR ratio group (77·6 ± 24·8%). Multiple regression analysis showed that even after adjustment for age, sex, type of vitiligo and transplanted cell density, there was no significant correlation between the extent of repigmentation and the DR ratio, indicating that patients treated with high DR ratio obtained a satisfactory result and showed no difference from the low DR ratio group. Conclusions  Various surgical procedures for the treatment of vitiligo which involve melanocyte transplantation or skin grafts have different inherent DR ratios. Transplantation of cultured pure melanocytes is an expensive and complicated procedure; however, it provides the highest DR ratio (> 1 : 10 and up to 1 : 60). Surgeons can select one of these methods for the treatment of vitiligo based on their experience and skill, on the size of lesions, and the availability of laboratory support.