ABSTRACT
Objective To determine the frequency of T helper type 22 (Th22) cells and expression level of interleukin-22 (IL-22) in peripheral blood of patients with psoriasis vulgaris,and to investigate their relationship with disease severity and clinical course.Methods Peripheral blood samples were obtained from 40 patients with psoriasis vulgaris and 30 healthy human controls.Five-color flow cytometry was performed to determine the percentage of Th22 cells in peripheral blood,and enzyme-linked immunosorbent assay (ELISA) to measure the expression of serum IL-22.Statistical analysis was carried out by t test and Pearson correlation analysis.Results Both the percentage of Th22 cells and serum level of IL-22 in peripheral blood were significantly higher in patients with psoriasis vulgaris than in healthy human controls (Th22 cells:0.65％ ± 0.48％ vs.0.33％ ± 0.15％,t =3.89,P ＜ 0.01; IL-22:(67.96 ± 14.32) vs.(40.59 ± 9.91) ng/L,t =9.45,P ＜ 0.01).Further more,Th22 cell percentage and IL-22 serum level in peripheral blood were both positively correlated with psoriasis area and severity index (PASI) in these patients (r =0.38,0.94,P ＜ 0.05 and 0.01,respectively),but neither of them correlated with clinical course of psoriasis vulgaris (r =0.20,0.10,respectively,both P ＞ 0.05).Conclusions The percentage of Th22 cells and level of IL-22 are increased in peripheral blood of patients with psoriasis vulgaris,and both of them are correlated with disease severity.