Clinical Significance Of IL-26 In Chronic Hepatitis C Patients

Objective: HCV infection is a major cause of chronic liver injury.Studies have shown that the immunological response caused by HCV infection is the main cause of hepatitis C liver damage,in which cytotoxic T lymphocytes(CTL)play an important role,but the concrete mechanism of the chronicity is still a complex progress to explain.Interleukin-26(IL-26)is a member of the IL-10 cytokine family,and its gene expression is highly specific for T cells.IL-26 can overexpression in chronic inflammation,induce bone marrow cells and some epithelial cells to produce proinflammatory cytokines,resulting in tissue damage.The present study aims at investigating the serum levels of IL-26 among the chronic hepatitis C(CHC)patients,healthy control and the group after treated by direct-acting antiviral agents(DAA),hopefully to draw a conclusion describing the connection between the expression and liver inflammation degree and to explore the value of IL-26 in the progression of HCV infection.Methods: A total of 31 CHC patients who underwent liver biopsy were enrolled in our study,and eleven of these patients received direct-acting antiviral agents(DAA).We also incorporated in 17 healthy controls with the same period.All of the CHC patients were randomly selected from the inpatients or outpatients of the Third Hospital of Hebei Medical University from October 2015 to November 2016,and the healthy controls were also recruited from the same hospital.All of the CHC were diagnosed according to the Guidelines on Prevention and Treatment for Chronic Hepatitis C in China(updated in 2015)developed by the Chinese Society Infectious Disease of and the Chinese Society of Hepatology respectively.We examined the regular serum biochemical indexes,such as the levels of aspartate transaminase(AST),alanine transaminase(ALT),total bilirubin(TB)were measured,along with HCV RNA load,and performed enzyme-linked immunosorbent assays(ELISA)to value the serum levels of IL-26.Results:1.Baseline Clinical CharacteristicsThe demographic data of the subjects were comparable.CHC patients had a obviously higher alanine transaminase(ALT),aspartate transaminase(AST),total bilimbin(TB)and direct bilirubin(DB)levels than healthy controls,P all<0.05.The difference of serum albumin(ALB)level between CHC group and healthy controls was not statistically significant,P >0.05.2.Serum IL-26 is enhanced in chronically HCV-infected patientsSerum levels of IL-26(3.52±0.27)in CHC patients were significantly higher than those in healthy controls(3.09±0.13,P <0.05).3.Correlation between serum IL-26 expression and regular laboratory indexesIn CHC group,the serum IL-26 level was positively related with ALT and AST levels(r=0.36,P<0.05;0.39,P<0.05).Serum IL-26 positively correlated with HCV RNA(r=0.38,P<0.05).4.IL-26 expressions in CHC liver tissues were significantly relevant with liver inflammation grades.CHC patients were divided into three groups according to the degree of inflammatory activity: 9 cases were mild group(G0/G1),6 cases were moderate group(G2)and 6 cases of severe group(G3).The level of serum IL-26 in the three groups showed no significant difference between the moderate group and the severe group.With the increase of inflammatory activity,the levels of serum IL-26 were significantly increased,and the three groups were higher than the healthy controls(3.09±0.13)(P<0.05).We found the levels of serum IL-26 in CHC patients were significantly relevant with the liver inflammation grades(r=0.67,P<0.01).5.Changes of IL-26 level in patients with chronic HCV infection before and after treatment with DAAThe level of serum IL-26 in patients with chronic HCV infection after DAA antiviral therapy(3.27 ± 0.06)was significantly lower than that before treatment(3.57 ± 0.26)(P<0.05).Conclusions:1.The expression of IL-26 in serum of patients with chronic hepatitis C was up-regulated,while was decreased after treated by direct-acting antivirals,suggesting that IL-26 plays a role in the process of HCV infects.2.IL-26 levels were significantly correlated with the inflammation degrees in CHC patients,suggesting IL-26 may participated in the process of inflammation of HCV infects as an inflammatory factor.