The comparison of tissue IL - 22 levels between Psoriasis and Vitiligo patients

Objective: Interleukin (IL)-22 is a cytokine that is involved in the modulation of tissue remodeling during inflammation. Different types of T cells secrete IL-22. IL-6 and tumor necrosis factor α (TNF-α) induce Th22 cells to produce IL-22, particularly in the skin, whereas γδ T cells produce IL-22 in response to IL-23, particularly in the lung. IL-22 is known to be expressed in many chronic inflammatory conditions, including several skin diseases. This study was planned to comparison the role of IL-22 receptor type 1 (IL-22R1) between psoriasis and vitiligo in skin biopsy specimens. Methods: Study involved 49 patients with psoriasis, 53 patients with vitiligo and 45 healthy control subjects. The clinical sign and PASI scores of psoriasis patients as well as the duration, and involved body area of vitiligo patients were recorded. Immunohistochemically, expression of IL22-R1 was investigated in the skin lesions of psoriasis and vitiligo patients and control group skin. Results: A statistically significant increase of the expression of IL22R1 was found in the skin biopsies of psoriasis patients compared with the vitiligo patients and control group subjects. In patients with psoriasis, there was a positive correlation between the expressions of IL-22R1 and PASI scores (p = 0.001, r = +0.572). In addition, there was no significant difference in epidermal IL-22R expression between vitiligo and the control group ( P=0.509). Conclusions: The present study has demonstrated that IL22-R1 doesn’t have a significant role in pathogenesis of the vitiligo and that Th22 cells may not be the pivotal cells in the pathophysiology of this disease.