Autologous Non-cultured Epidermal Cell Suspension Transplantation in the Treatment of Vitiligo

1\. Patient recruitment Inclusion criteria：

1. Patients diagnosed as vitiligo, according to the "Vitiligo Diagnosis and Treatment Consensus (2021 edition) 2. Segmental and unclassified vitiligo stable for 6 months, Non-segmental vitiligo stable for 1 year and resistant to medication and phototherapy 3. BSA≥5% 4. Sign the informed consent and be willing to undergo surgical treatment 5. 8-65 years old, both genders Exclusion criteria：

1\) Severe visceral or infectious disease not suitable for surgical treatment 2) Tendency toward keloid formation 3) Coagulation defects 4) Unable to complete follow-up on time 2. Non-cultured epidermal cell suspension transplantation procedure

1. Thin split thickness skin grafts of about one-tenth of the recipient area were taken from the donor site(anterolateral thigh)after aseptic precautions. 2. The suspension for non-cultured epidermal cell suspension transplantation was prepared by the cell sorting kit (Primcell, Jiangsu Repatec Life Science Co.,Ltd). 3. The recipient site was cleaned with 75% alcohol and anesthetized by applying topical compound lidocaine cream for 45 to 60 minutes. Then the recipient skin was uniformly dermabraded using an electrical dermabrader set at 10,000 to 20,000 rpm until punctate bleeding points appeared. Dermabrasion was performed 0.5 mm beyond the margin of the recipient area to minimize the perigraft halo of depigmentation. 4. The cell suspension was applied onto the dermabraded recipient area. The recipient site was then fixed firmly with 4 layers of dressing. From the inner to the outer layer, these dressings were: non adherent wound dressing , paraffin-embedded gauze, dry gauze, and elastic bandage. The dressings were removed 10 days after transplantation.

3\. Postoperative Follow-Up All patients returned to the hospital for follow-up examinations at 2 weeks, 1month, 2 months, 3 months, 4 months, 5 months and 6 months after transplantation.

The repigmentation was graded based on the percentage of the area of repigmentation as poor (less than 25%), good (26%-50%), very good (51%-75%), or excellent (more than 75%).

The melanin index (MI) and erythema index (EI) of the recipient sites were measured using a Mexameter MX18 (Courage 1Khazaka Electronic GmbH, Koln, Germany). The relative MI (RMI) and relative EI (REI) were calculated as the ratio of the MI or EI of the recipient sites relative to the symmetrical control skin region.

4\. Laboratory Tests The cell number and vitality of the suspension was determined by an automatic intelligent cell counter. The flow cytometry was used to analyze the cell types.

• Relative Melanin Index [Time frame: 2 weeks, 1month, 2 months, 3 months, 4 months, 5 months and 6 months after transplantation]
• Relative erythema index [Time frame: 2 weeks, 1month, 2 months, 3 months, 4 months, 5 months and 6 months after transplantation]