The effect of NB-UVB on noncultured melanocyte and keratinocyte transplantation in treatment of generalized vitiligo using two different donor-to-recipient ratios.

Background: The melanocyte and keratinocyte transplantation procedure (MKTP) is a safe and effective procedure in treatment of vitiligo. Major advantage of this technique is that a small area of donor skin is needed to cover a large recipient area. To date, there is no consensus on the optimal donor-to-recipient ratio (D/R) required to achieve acceptable repigmentation following melanocyte and keratinocyte transplantation procedure (MKTP) in generalized vitiligo. It has been postulated that the addition of post-transplantation phototherapy may enhance the results. This is first study to assess two different (D/R) ratios with or without adjuvant phototherapy.

Objective: To compare the repigmentation after MKTP using two different D/R ratios (1/3 and 1/10) with and without adjuvant phototherapy (NB-UVB).

Methods And Materials: In this non randomized prospective clinical trial, 42 patients with stable generalized vitiligo bilateral and symmetrical in distribution were included. Patients were divided into two groups, 21 patients with a total of 50 lesions were treated with MKTP using a D/R ratio of 1/3 (Group I; 3000 ± 500 cell/mm ) and the other 21 patients with a total of 52 lesions were treated by MKTP using a D/R ratio of 1/10 (Group II; 1000 ± 200 cell/mm ). To study the role of adjuvant phototherapy on repigmentation, lesions in each patient were divided into two subgroups (a and b): lesions in subgroups Ia and IIa (did not receive NB-UVB) and lesions in subgroups Ib and IIb (received adjuvant phototherapy NB-UVB, two sessions per week for 6 months). The overall grading of repigmentation used was excellent (90%-100% repigmentation), good (75%-89%), fair (50%-74%), and poor (<50%). Also, the percentage of VASI change and color matching were used to assess the results. The study design was approved by the ethical committee of the Faculty of Medicine, Assiut University (IRB attached).

Results: The mean percentage of repigmentation was significantly better in group I than group II cases in both areas with or without adjuvant NB-UVB. It was 86.00 ± 16.21 and 87.62 ± 11.66 in subgroups Ia and Ib, respectively, vs 24.14 ± 18.08 and 29.98 ± 16.34 in subgroups IIa and IIb, respectively (P value was 0.000). The percent of excellent response was significantly better in group I than group II. It was 60% and 64% in subgroups Ia and Ib, respectively, and 7.6 and 11.5 in subgroups IIa and IIb, respectively (P value was 0.000). The mean percentage of VASI change was significantly better in group I than group II cases in both areas. It was -90.74 ± 15.84 and -92.06 ± 11.86 in subgroups Ia and Ib, respectively, vs -23.10 ± 32.85 and -26.03 ± 35.15 in subgroups IIa and IIb, respectively (P value was 0.000). The percent of excellent color match was better in group I than group II. It was 84% and 88% in subgroups Ia and Ib, respectively, vs 34.6 in both subgroups IIa and IIb (P < 0.05). A higher density of epidermal cells was transplanted in the recipient area in group I (3000 ± 500 cell/mm ) compared to group II (1000 ± 200 cell/mm ). There were no statistically significant differences between subgroups (Ia vs Ib and IIa vs IIb) although percentage of repigmentation was slightly better in NB-UVB subgroups.

Conclusions: The higher density of epidermal cells used in the suspension, the higher the percentage of repigmentation obtained. The usage of adjuvant phototherapy following NKMT can enhance the repigmentation response.