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

BACKGROUND: Vitiligo is an autoimmune disease associated with alteration in levels of various cytokines. However, there are very few studies in this regard. OBJECTIVES: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.