Increased IL-23 and IL-17 expression by peripheral blood cells of patients with primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a typical autoimmune disease for which the pathogenesis remains unclear. IL-23 and IL-17 are pro-inflammatory cytokines of the IL-23/IL-17 axis, which may play a key role in the pathogenesis of autoimmune diseases. In this study, we investigated the expression of IL-23 and IL-17 in the peripheral blood of patients with PBC and its clinical significance. We used quantitative PCR to determine mRNA expressions of IL-23, IL-23 receptor, and IL-17 in peripheral blood mononuclear cells (PBMC) from PBC patients. ELISA's were used to determine patients' serum levels of IL-23 and IL-17. IL-23- and IL-17-producing cells in liver biopsis were also analyzed. Compared to a healthy control group, the mRNA expression levels of IL-23 p19, its corresponding receptor, IL-23R, and IL-17 in PBMC's from PBC patients were significantly increased, and these levels were correlated with PBC disease stages. PBC patients' serum levels of IL-23 and IL-17 were higher than those in a post-hepatic cirrhosis group and a healthy group, and were significantly higher in the early PBC disease stages than in the advanced PBC stages. There were significantly more IL23+ and IL-17+ mononuclear cells in portal areas of liver tissues in advanced stages of this disease than in the early stages. The serum levels of IL-23 and IL-17 in PBC patients were positively correlated with serum GGT levels. Thus, IL-23 and IL-17 may play an important role in the pathogenesis of PBC by promoting inflammation. Because the IL-23 and IL-17 levels in the peripheral blood of PBC patients were increased and were correlated with clinical stages, they may be indices that could be used to clinically monitor PBC. (c) 2013 Elsevier Ltd. All rights reserved.