Effect of Narrow Band –UVB Phototherapy on Circulating T-Regulatory cells and Serum IL-17 Level in Egyptian Patients with Non-Segmental Vitiligo

Abstract

Background: Vitiligo is an acquired chronic depigmenting disorder of the skin, characterized by the development of milky white macules and patches resulting from a selective loss of epidermal melanocytes. There are various theories about its pathogenesis and the etiology is multifactorial associating genetic and environmental factors together with metabolic and immune alterations. Objective: To demonstrate the role of circulating T regulatory cells (Treg) (specifically CD4 + , CD4 + 25 + , CD4 + 25 + FoxP3) and serum level of IL-17 in pathogenesis of non-segmental vitiligo (NSV) in Egyptian patients. Patients and methods: This case-control study was carried out on eighty subjects in the period from January 2018 to March 2020, attending Dermatology, Andrology & STDs Outpatient Clinic of Mansoura University Hospital. Subjects were classified into two groups: Group (1): patients group included forty patients suffering from NSV (vitiligo patients group). Group (2): control group included forty persons who were selected from hospital workers with no personal or family history of vitiligo or systemic autoimmune diseases in their first-degree relatives. Results: After NBU-VB treatment, there was a highly statistically significant increase in CD4 + %, CD4 + 25 + % and CD4 + 25 + FoxP3% expression with a mean of 12.1 ± 4 versus 10 ± 3.2, 3.5 ± 1.1 versus 3.2 ± 1 and 1.8 ± 0.6 versus 1.1 ± 0.3 when compared to before treatment levels respectively. Also, a highly statistically significant decrease in IL-17 level with the mean of 14.3 ± 4.1 versus 19.9 ± 6 pg/mL when compared to before treatment levels. There was a highly statistically significant positive correlation between CD4 + 25 + % expression and CD4 + % expression in vitiligo group before and after treatment. Conclusion: Lower CD4 + %, CD4 + 25+% and CD4 + 25 + FoxP3% expression and elevated serum levels of IL-17 positively were correlated with disease severity.

Meta-Analysis of Alterations in Regulatory T Cells’ Frequency and Suppressive Capacity in Patients with Vitiligo

“…Nevertheless, our meta-analysis suggested a trend of increased Treg cells' frequency after treatment as there was 1.16 SMD increase in Tregs' frequency after treatment (Figure 5(a)). Moreover, our meta-analysis suggested improved Tregs' frequency, FOXP3, and IL-10 expression posttreatment in human and mice model studies, which is in concordance to the previous studies [47][48][49][50][51][52][53].…”

“…Additionally, polymeric nanoparticles containing rapamycin and autoantigens induce antigen-specific immune tolerance, thereby inhibiting vitiligo in mouse models of vitiligo [ 53 ]. Furthermore, in human studies, tacrolimus, miR-155, and HO-1 increase the IL-10 expression in vitiligo lesions, whereas narrow band-UVB phototherapy, miR-21-5p, and miR-155 enhance the Tregs' frequency and FOXP3 levels, thereby suppressing the melanocyte destruction caused by unregulated Th1 pathways [ 19 , 21 , 48 , 49 , 52 ]. Therefore, such Treg-based therapeutics can control depigmentation and support immune tolerance in vitiligo.…”