Expressions Of Il-22 In Circulating CD4+/CD8+T Cells And Their Correlation With Systemic Lupus Erythematosus

Objective To explore the role of interleukin 22 (IL-22) in systemic lupus erythematosus (SLE), so as to provide scientific evidences for the pathogenetic mechanisms study and treatment of SLE.Methods Five-color flow cytometry (FCM) was used to assess IL-22/IL-10R2 production of CD4+ /CD8+ T cells in PBMCs from 31 patients with SLE and 22 healthy control subjects, following stimulation ex vivo with phorbol 12-myristate 13-acetate and ionomycin for 4 hours.Results We found that the percentages of IL-22 or IL-10R2 -positive CD4+ T cells were increased in the PBMCs of patients with SLE compared with healthy control subjects (Z= -3.29, P=0.001; Z= -4.08, P<0.001, respectively), whereas no significant differences in the percentages of IL-22 or IL-10R2-positive CD8+ T cells. There was a strongly positive correlation between the proportions of CD4+ T cells expressing IL-22 and SLEDAI score (rs=0.65, P<0.001). Furthermore, the frequencies of IL-22-positive CD4+ T cells were significantly higher in SLE patients with nephritis (LN) than those without nephritis (Z = -2.72, P < 0.01). However, the frequencies of IL-10R2-positive CD4+ T cells were not associated with SLEDAI score or LN.Conclusions In conclusion, increased frequencies of IL-22-positive CD4+ T cells in patients with SLE, and positive correlation with SLEDAI score and lupus nephritis suggest that this cytokine may be implicated in the pathogenesis of the disease.