Zinc-α2-Glycoprotein (ZAG): A New Deficiency in Vitiligo Patients.

Zinc-α2-glycoprotein (ZAG), a recently identified adipokine, is a multidisciplinary protein, which is secreted in various body fluids. The ZAG plays roles in lipolysis, regulation of metabolism, cell proliferation and differentiation, regulation of melanin synthesis, cell adhesion, and immunoregulation. The aim of this study is to estimate serum and tissue levels of ZAG in patients with vitiligo. The study included 30 vitiligo patients and 30 healthy controls. Lesional skin biopsy was performed, and blood sample was retrieved to determine the level of ZAG in blood using ELISA kit. In this study, the mean level of ZAG was found to be significantly lower in the vitiligo patients' tissue in comparison with the healthy control subjects' tissue ( p=0.001); the level of ZAG was also lower in vitiligo patients' serum in comparison with the healthy control subjects' serum ( p=0.001). A highly significant correlation was observed between the duration of the disease and the level of ZAG in the tissue of patients (r =0.9; p=0.001). Also a highly significant positive correlation was observed between the age of patients and the level of ZAG in the tissue (r =0.5; p=0.006). Diminishing of ZAG in serum and tissue of vitiligo patients is another important player sharing in the complex pathogenesis of vitiligo.