Serum Expression of IL-33 and ST2 in Patients with Psoriasis Vulgaris

Background: Psoriasis vulgaris (PsV) is an immune-mediated skin disease of unknown mechanism. Interleukin 33 (IL-33) is a member of IL-1 cytokine family and suppression of tumorigenicity 2 (ST2) is the specific ligand of IL-33. It has been found that IL 33 and ST2 are increased in psoriatic lesions, but the expression levels in serum and their relationship to clinical features are still unclear. The aim of this study is to assess IL-33, ST2, IL-17 and IL-5 serum levels as well as serum concentration of blood glucose and blood lipids in PsV patients and their relationship with clinical characteristics. Methods: Sixty-eight PsV samples and 60 healthy individuals were recruited. Serum levels of IL-33, ST2, IL-17 and IL-5 were measured by enzyme-linked immunosorbent assay and blood glucose and blood lipid were assayed by automatic biochemical analyzer. Results: Serum levels of IL-33, ST2, IL-17 and IL-5 were increased significantly in PsV patients compared with controls (P< 0.01). Cytokines were overexpressed in PsV patients during active stages compared with controls (P < 0.05). Expression levels of IL-33, ST2 and IL-17 confirmed a significance in different severity groups of PsV patients (P < 0.05). Serum concentration of triglyceride (TG) was also increased compared with controls (P = 0.024). IL-33 levels were positively correlated with total cholesterol (TC) levels (r= 0.319, P = 0.008). Conclusion: IL-33/ST2 could generally reflect the activity and disease severity in PsV patients, which indicates that the IL-33/ST2 signaling pathway plays an important role in the pathogenesis of PsV.