Introduction: Vitiligo is a depigmentation disorder in skin that occurs due to the loss of melanocytes from the epidermis. The etiology and pathogenesis of vitiligo are still unclear. Regulatory T cells (Tregs) are one of the main immune system elements which have a considerable role in disease establishment.
Aim of the study: to study the pathogenesis of vitiligo and investigate the alteration of Treg cells and its associated substance among vitiligo patients compared with healthy controls
Subjects and Method: We utilized Cochrane Library, Web of Science, Scopus, PubMed to retrieve studies comparing vitiligo patients with healthy controls regarding the frequency of Tregs, the levels of IL-17, FOXP3, IL-10, TGF-β, and the suppressive capacity over CD4+ and CD+8. NHLB was utilized to assess the quality assessment of the included studies.
Results: 19 studies met our inclusion criteria and were included in our meta-analysis. Our analysis demonstrated that compared to healthy controls, vitiligo patients had significantly decreased Treg cells' frequency (P < 0.001), reduced suppressive capacity over CD4+ and CD8+ (P < 0.001), and decreased Tregs-associated substances including TGF-β (P = 0.05), IL-10 (P = 0.004), and FOXP3 (P < 0.001). However, Vitiligo cases was associated with an increased level of IL-17 (P < 0.001).
Conclusion: Treg cells are involved in vitiligo pathogenesis. Vitiligo patients have a significantly diminished expression and frequency of Treg cells and Treg-associated elements such as TGF-β, FOXP3, and IL-10 levels. However, IL-17 was found to be increased in vitiligo patients