ABSTRACT
Objective To investigate the role of interleukin-22 (IL-22) in the pathogenesis of pityriasis rosea (PR).Methods Peripheral venous blood samples were obtained from 48 patients with PR in acute stage and recovery stage and from 20 healthy human controls.Real-time fluorescence-based quantitative PCR was performed to measure the mRNA expression of IL-22 in peripheral blood mononuclear cells (PBMCs),and enzyme-linked immunosorbent assay (ELISA) to determine the level of IL-22 in sera.Results The relative expression level of IL-22 mRNA in the patients with PR in recovery stage was significantly higher than that in the healthy controls (2.89 ±0.91 vs.1.91 ± 0.60,t =3.84,P ＜ 0.05),but lower than that in the patients in acute stage (2.89 ± 0.91 vs.4.15 ±1.36,t =3.61,P ＜ 0.05).Similarly,the level of serum IL-22 was significantly increased in the patients with PR in recovery stage compared with the healthy controls ((21.44 ± 7.33) vs.(13.22 ± 4.26) ng/L,t =4.49,P ＜ 0.05),and increased in the patients with PR in acute stage compared with those in recovery stage ((36.87 ± 10.63) vs.(21.44 ± 7.33) ng/L,t =5.01,P ＜ 0.05).The level of serum IL-22 was positively correlated with the stage of PR (r =0.883,P ＜ 0.05).Conclusions IL-22 is overexpressed in PBMCs and sera of patients with PR,implying that IL-22 is involved in the pathogenesis of PR.