Cytokine profile (IL-2, IL-6, IL-17, IL-22, and TNF-α) in vitiligo-New insight into pathogenesis of disease.

Abstract

Vitiligo is an autoimmune disease associated with alteration in levels of various cytokines. However, there are very few studies in this regard. To assess the serum levels of cytokines secreted by Th1 (IL-2, TNF-α), Th2 (IL-6), and Th17 cells (IL-17, IL-22) in patients with localized vitiligo and generalized vitiligo and to correlate their levels with the extent, duration, and activity of disease. Sixty patients of vitiligo (30 each of localized and generalized) and 30 controls were recruited in the study. Serum IL-2, -6, -17, -22, and TNF-α levels were measured by enzyme-linked immunosorbent assay (ELISA) in all patients and healthy controls, and their levels were correlated with the extent, duration, and activity of vitiligo. We observed significantly raised levels of IL-2, -6, -17, -22, and TNF-α in both localized vitiligo and generalized vitiligo (P < .05). IL-2 was significantly raised (P = .028) in localized vitiligo, whereas IL-17 and IL-22 were significantly raised in generalized vitiligo (P = .00 and P = .019, respectively). Activity of disease showed positive correlation with serum TNF-α levels (P = .015) in localized vitiligo. Positive correlation of IL-17 (R = .238) with body surface area (BSA) was observed in patients with generalized vitiligo. Our study shows that cytokines secreted by Th17 cells play an important role in maintenance and spread of vitiligo as they increase in line with extent of disease. Also TNF-α increases in proportion with activity of disease, hence may act as biomarker for identifying patient with aggressive disease.