ABSTRACT
BACKGROUND/AIMS: The aims of our study are to assess the frequency of peripheral blood mononuclear cell (PBMC) proliferation and cytokine profiles to hepatitis C virus (HCV) core protein and NS3 protein to search the potential immunosuppressive effect of HCV core in chronically HCV-infected patients. Subjects and METHODS: Thirty two anti-HCV-positive patients with chronic liver diseases, eight HBsAg-positive patients with chronic liver diseases, and six healthy adults were the subjects of our study. Using recombinant HCV core and NS3, proliferative response of PBMC and cytokine production were determined. RESULTS: Fifty nine percent and thirteen percent of patients with HCV-related chronic liver diseases showed positive PBMC proliferation to HCV core and NS3, respectively. Thirty four percent and fifty nine percent of patients with HCV-related chronic liver diseases showed significant production of interferon-gamma to HCV core and NS3, respectively. IL-4 production was negligible. When the PBMC were treated with HCV core and NS3 concurrently, or HCV core and phytohemagglutinin concurrently, the stimulation indices were significantly decreased compared to those treated either with NS3 or PHA without core. CONCLUSIONS: Although about two thirds of chronically HCV-infected patients with liver diseases showed the PBMC proliferation and Th 1 type cytokine profile, they could not eradicate the viral infection. This ineffective immune response seems to play a role in the pathogenesis of chronic inflammatory liver disease resulting in liver cirrhosis and hepatocellular carcinoma. HCV core showed a potential immunosuppressive effect, which has important meaning for the mechanism of HCV persistence.