Serological Studies on Circulating Interferon-γ in Patients Infected with Hepatitis C Virus

Abstract

Egypt has probably the highest hepatitis C virus (HCV) prevalence worldwide. HCV is a leading cause of cirrhosis and liver cancer. The pathogenesis of chronic liver disease still poorly understood. Recently, experimental data have shown the critical role of pro-inflammatory cytokines like interferon gamma (IFN-γ) in the development of liver injury. Moreover, the relationship between the course of the disease and the number and function of CD4+ T-helper cells, CD3+ T-cells and natural killer cells has been shown to be important in many studies. The mechanisms involved in chronic HCV infection, especially the immune responses induced by host immune factors, have become a topic of great interest for researchers. Liver function tests such as, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin and albumin were measured. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting to identify interferon gamma (IFN-γ) and Enzyme Linked Immunosorbent Assay (ELISA) as a sensitive and specific method was used to evaluate the levels of IFN-γ in sera of chronic HCV patients (n = 110); and hepatocellular carcinoma (HCC) of HCV patients (n = 30) in addition, sera of 30 healthy individuals were used as negative controls. Peripheral blood mono-nuclear cells of all patients in addition to healthy individuals were collected and the different lymphocyte populations, including CD3+ T-cells, CD4+ Th-cells and CD3-/CD16+CD56+‏ NK cells, were analyzed by flow cytometry. In the present study, after analysis, hepatocellular carcinoma (HCC) patients had higher values of AST, ALT, and bilirubin but they had lower levels of serum albumin than those of chronic hepatitis C (CHC) patients or healthy individuals. Sera of disease groups showed elevated IFN-γ levels compared with healthy . The differences were also remain statistically significant when CHC group was compared with HCC group. After 3 months of receiving daclatasvir and sofosbuvir combination treatment for non-cirrhotic and compensated cirrhotic patients and receiving daclatasvir, sofosbuvir and ribavirin combination treatment for decompensated cirrhotic patients, serum concentration of IFN-γ was found to be significantly reduced.