Abstract: 【Abstract】 Objective To investigate the effect of 308-nm light-emitting diode （LED） phototherapy at escalating doses after autologous melanocyte transplantation on the repigmentation in patients with refractory stable vitiligo. Methods A prospective, randomized, self-controlled trial was conducted. Twelve patients with refractory stable vitiligo （a total of 17 skin lesions） were collected from the Department of Dermatology, People's Hospital of Xinjiang Uygur Autonomous Region from November 2023 to September 2024. Autologous cultured melanocyte transplantation was performed. One week after the inner layer of petrolatum gauze had fallen off, each white patch was bisected by the midline and randomly divided into a test group and a control group; both groups received 308-nm LED light irradiation at an initial dose of 50 mJ/cm2; then, the test group received a slow （5%） dose escalation, while the control group received a quick （10%） dose escalation. The repigmentation outcomes, clinical efficacy and safety were observed at 1, 3, and 6 months after the start of phototherapy. Results A total of 12 patients with refractory stable vitiligo were collected, including 3 males and 9 females, aged 5 to 59 （29.4 ± 19.6） years. At 1 month after phototherapy, there was no significant difference in the vitiligo repigmentation area score between the test group and the control group （P = 0.666）; at 3 months after phototherapy, the vitiligo repigmentation area score was significantly higher in the test group （54.45 ［5.17, 85.50］ points） than in the control group （39.75 ［4.52, 65.05］ points, Z = -2.51, P = 0.012）; at 6 months after phototherapy, no significant difference in the vitiligo repigmentation area score was observed between the two groups （P = 0.11）. In the test group, the marked response rate increased from 41.18% （7/17） at 1 month to 58.82% （10/17） and 58.82% （10/17） at 3 and 6 months after treatment, respectively; in the control group, it increased from 29.41% （5/17） at 1 month to 35.29% （6/17） and 47.06% （8/17） at 3 and 6 months after treatment, respectively. At 1 month after treatment, the response rate was 58.82% （10/17） in the test group, and 64.71% （11/17） in the control group, which both increased to 70.59% （12/17） at 3 and 6 months after treatment. There were no significant differences in the marked response rates or response rates between the two groups at different time points after treatment （all P > 0.05）. The maximum dose of 308-nm LED light was 106.0 （87.0, 152.5） mJ/cm2 in the test group, and 219.0 （200.5, 268.5） mJ/cm2 in the control group; the total accumulated dose of 308-nm LED light was 2 101.0 （1 865.0, 2 270.5） mJ/cm2 in the test group, and 3 411.0 （2 683.5, 4 016.5） mJ/cm2 in the control group. Blisters occurred in 3 lesions （17.6%） in the control group, while no adverse reactions were observed in the test group. Seven patients （58.3%） preferred the low-dose escalation irradiation protocol in the test group. Conclusion Autologous melanocyte transplantation combined with 308-nm LED phototherapy initiated at a minimum dose and followed by a 5% dose-escalation irradiation protocol exhibited comparable efficacy but superior safety profiles compared with a conventional 10% dose-escalation irradiation protocol in the treatment of refractory stable vitiligo.

Key words: Vitiligo, Autologous cell transplantation, Ultraviolet Therapy, 308nm SQ LED phototherapy, Clinical Efficacy, Safety