The Preliminary Study On Expression Of Peripheral Blood Th17 Cell And IL-17 In Primary Biliary Cirrhosis

BackgroundPrimary biliary cirrhosis (PBC) is an autoimmune chronic cholestatic liver disease characterized by destruction of intrahepatic bile ducts and deveo-pment of cirrhosis and liver failure. Serologically, PBC is characterized by the presence of antimitochondrial antibodies (AMA).T cell-mediated abnormal immune response,the abnormal changes in the host itself antigen and other mechanisms may be involved in the occurrence of PBC. The morbidity of PBC is increasing in recent years in middle-aged women in North American. In China, there is not systematically epidemic data with PBC, however, with the developing of diagnostic technique, the morbility of PBC is increasing. At present,there is no effectively curative method for PBC. Ursodeoxycholic acid(UDCA)is known as the most effective drug for PBC. It can only provide symptomatic relief of cholestasis but can not block disease course. At late stage of PBC, liver transplantation could be the last and only choice.CD4-positive T helper type 17 (Th17) cells, characterized by the secretion of interleukin(IL)-17, have been implicated in the pathogenesisof autoimmune diseases. The researchers found that Th17 cells is more efficience to induce EAE than Thl cells in experimental autoimmune encephalomyelitis(EAE) in mice model. They also found that the EAE mice injected with IL-17 can enhance the symptoms of inflammatory and severity. Conversely, IL-17-/- mice can delay the progression of EAE. Animal experiments discovered that CD4+T cells can secrete higher IL-17 in mice. They also found the over-expression of Th17 cells and IL-17 in the autoimmune liver tissue and peripheral Blood in PBC mouse models.Those results suggest that Th17 cells play a important role in the pathogenesis of PBC. ObjectiveThis study is about three groups of patients with primary biliary cirrhosis (PBC) and HBV-related posthepatitic cirrhosis(HBV-PHC) and health controls (HC) which were performed inperipheral blood Thl7 cells/CD4+Tcells ratio and the expression levels of IL-17, Simultaneously analyzed the correlation between the serum levels of IL-17 and serum markers of liver injuryed glutamyl transpeptidase peptidase(GGT),alkaline phosphatase (ALP), for the purpose of studying the function and its clinical significance of peripheral blood Th17 cells and IL-17 in PBC patients. Those results may provide some experimental evidenc with Th17 cells in autoimmune liver diseases and provide the immune target of a new idea for therapeutic.Methods1. The ratio of Thl7 cells/CD4+T cell in the peripheral blood were detected By Flow cytometry (FCM).2. The levels serum of IL-17 were measured by enzyme-linked immunosorbent assay (ELISA) and the serum levels of GGT and ALP wre measured by enzyme kinetic rate. At the same time, compared the correlation between the Levels of IL-17 and GGT,ALP.3. The IL-17 mRNA gene expression in the peripheral blood mononuclear cells were measured by real time quantitative RT-PCR.Results1. PBMC of three groups were stimulated by PMA/Ionomycin and detected by flow cytometry after cultured 4h, eventually IL-17+ in scatter staining indicated Th17 cells and using CellQuest software to analyze data. Compared to HC group [(0.58±0.20)%], Th17 cells in peripheral blood in PBC patient group[(0.83±0.57)%] and HBV-PHC[(0.81±0.45)%)] (P<0.05). But between PBC and HBV-PHC (P>0.05).2. The serum leves of IL-17 in the three groups were measured by ELISA. The serum levels of IL-17 in PBC[(24.6±9.7)pg/mL] and HBV-PHC [(21.6±6.1)pg/mL] was significantly higher than HC[(18.0±2.1)pg/mL] (P<0.05). Between PBC and HBV-PHC(P<0.05).At the same time, the concentrations of serum GGT, ALT which are liver injuryed markers were measured by enzyme kinetic rate. The Concentration of GGT[(320±267)U/L] and [ALP(204±126)U/L] in PBC group, the concentration of GGT [(246±156) U/L] and ALP[(132±113)U/L] in HBV-PHC, the concentrationin of GGT[(23±12) U/L] and ALP [(60±3)U/L] in HC, any comp-Arison between the two groups (P<0.05).3. IL-17mRNA gene expression in the peripheral blood mononuclear cells were measured by real time quantitative RT-PCR. Compared with HBV-PHC and HC the expression of IL-17 were significantly higher in PBC patient group (P<0.05) Excepally the expression of PBC groups is 2.21 times than HC group (P<0.05). Between HBV-PHC and healthy groups(P<0.05).4. Based on the serum levels of IL-17 and GGT, ALP, we studied that correlation between the index statistics analysis of three groups. The results showed PBC patients with the serum levels of IL-17 and GGT, ALP were positively correlated(P<0.05). HBV-PHC and HC,no significant correlation(P>0.05).ConclusionIn this study, the results showed that the levels of Th17 cells in periph-eral blood and the serum levels of IL-17 were significantly elevated in PBC group and HBV-PHC group. Compared to HC group, which the difference was significantly. The levels IL-17 mRNA of peripheral blood mononuclear cells were significantly elevated in PBC group compared to HBV-PHC group and HC group, which the difference were statistically significant. Th17 cells and their secretion of proinflammatory cytokines IL-17 may play a important role in the prognosis of PBC and the inflammatory immune disease. There is no specific cure for PBC, so further studies are required to clarify the effect of Th17 cells in the pathogenesis of PBC.It can help us rebuild the immune system, but also provide new ideas for the strateies of PBC.