The Interplay Between IL-38 and TNF-α in Vitiligo: Investigating their roles as Opposing Immunoregulatory Cytokines in Autoimmune Skin Disease.

Abstract

Pro-inflammatory and anti-inflammatory cytokines play an essential role in the development of an immune system imbalance seen in vitiligo. The pro-inflammatory cytokine, tumor necrosis factor-alpha (TNF-α), and the newly described anti-inflammatory cytokine, interleukin-38 (IL-38), appear to have opposing functions in the pathophysiology of vitiligo. Objective: The aim of this study is to assess the levels of serum IL-38 and TNF-α in vitiligo patients compared to healthy subjects and their correlations with clinical features, such as extent, duration, and activity. Methods: This cross-sectional study included 70 patients clinically diagnosed with vitiligo and 70 healthy control subjects. Serum cytokines were quantitatively detected using ELISA tests, and patients' disease activity was calculated using the Vitiligo Area Scoring Index (VASI). The statistical analysis included a t-test and Pearson correlation, with a significance value of p < 0.05. Results: In contrast to the control group, patients with vitiligo showed higher levels of both IL-38 (63.2 ± 12.2 pg/mL) (p < 0.001) and TNF-α (75.7 ± 16.8 pg/mL) (p < 0.001). The activity of lesions in vitiligo was related to high concentrations of serum cytokines. There were direct correlations between IL-38 and TNF-α (r = 0.698, p < 0.001), along with other vitiligo-related parameters, such as VASI score, extent of lesions, duration of the disease, erythrocyte sedimentation rate (ESR), and CRP. Conclusion: It seems that the upregulation of IL-38 and TNF-α plays a crucial role in regulating immune responses in vitiligo. The results of our study indicate that IL-38 can be considered a promising biomarker in vitiligo.