Interleukin-17 level in patients with vitiligo: A systematic review and meta-analysis

The role of the pro-inflammatory cytokine, interleukin (IL)-17 is being continuously explored in various autoimmune disorders. Studies have assessed the levels of IL-17 in vitiligo patients. This study aims to evaluate the IL-17 levels in vitiligo patients in comparison with the healthy controls by performing a meta-analysis.

A systematic review of the existing literature was performed in PubMed, Scopus and Cochrane databases by two authors independently. The data required to calculate the pooled effect size in the form of standardised mean difference (SMD) with the corresponding 95% confidence interval (CI) were extracted from the eligible studies. Separate analyses for active and stable vitiligo were also performed.

A total of 11 case-control studies with 626 vitiligo patients and 475 healthy controls were included. Random-effects meta-analysis found significantly higher serum IL-17 levels in vitiligo patients compared with the healthy controls (SMD = 1.67, 95% CI 1.11 to 2.22, P < 0.001). The IL-17 levels were higher in both active (SMD = 1.31, 95% CI 0.76 to 1.86) and stable (SMD = 1.47, 95% CI 0.59 to 2.35) vitiligo patients compared with the healthy controls. The skin IL-17 levels were also significantly higher in vitiligo patients (SMD = 1.28, 95% CI 0.82 to 1.74). Heterogeneity in the baseline characteristics of the included studies was the major limitation of this study.

These results suggest that vitiligo patients have significantly elevated IL-17 levels. Further examination of this association could have implications for the treatment of vitiligo.