Clinical Significance of Decreased Interleukin-35 Expression in Patients with Psoriasis.

CD4+T cells and their related cytokines play an important role in the pathogenesis of psoriasis, a chronic, recurrent, inflammatory skin disease. The role of IL-35, an immunosuppressive cytokine involved in many autoimmune diseases, in the pathogenesis of psoriasis is unclear. In this study IL-35 expression and its clinical significance in patients with psoriasis were evaluated. Protein and mRNA levels of specified markers were measured by ELISA and qRT-PCR, respectively. It was found that plasma IL-35 concentrations were lower in patients with psoriasis than in healthy individuals (Z=-6.525, P<0.0001). mRNA titers of Ebi3 and p35 were lower in peripheral blood mononuclear cells from patients with psoriasis than in those from healthy individuals (Z=-5.078, P<0.0001; Z=-2.609, P=0.009, respectively). The areas under the receiver-operating characteristic (ROC) curves for IL-35, Ebi3 and p35 in patients with psoriasis versus controls were 0.86, 0.78 and 0.64, respectively. Pearson correlation analysis showed that, in patients with psoriasis, plasma IL-35 expression correlated negatively with concentrations of INF-, tumor necrosis factor-alpha, IL-23, -17, and -22, and the Psoriasis Activity and Severity Index and positively with concentrations of transforming growth factor beta and IL-10 . In summary, IL-35 may mediate pathogenesis of psoriasis by influencing expression of Th1/Th17/T-reg-related cytokines and may therefore be a putative target for monitoring or treating psoriasis.