Viral hepatitis: virus/host interaction

摘要: Hepatitis A virus is considered directly cytopathic to the liver cell. Severity of damage dictated by viral load. Acute infection followed sustained immunity virus. B (HBV) and C (HCV) viruses are noncytopathic, hepatotropic that cause acute chronic hepatitis hepatoma. Cellular humoral immune responses responsible not only for clearance but also hepatocyte damage. T-cell response HBV vigorous, polyclonal, multispecific in acutely infected patients who clear while it weak narrowly focused chronically patients. It mainly executed cytotoxic T lymphocytes (CTL), which destroy hepatocytes secrete antiviral cytokines interrupt life cycle. HCV strong both Whether susceptible a cytokine-mediated type control unknown. The ability persist despite CTL suggests either less visible or responsive signals than HBV. Both viruses, especially HCV, have high mutation rate, leading occurrence variant genomes with growth advantage escaping recognition.