Platelets Promote Liver Immunopathology Contributing to Hepatitis B Virus-Mediated Hepatocarcinogenesis

Chronic hepatitis B virus (HBV) infection is a major risk factor for the development of hepatocellular carcinoma (HCC). Among the pathogenetic factors triggered by HBV, virus-specific CD8+ T cells play and important role in disease pathogenesis by promoting necroinflammatory liver damage. Accordingly, amelioration of immune-mediated chronic liver injury may prevent HCC. Platelets facilitate this process by sustaining the hepatic accumulation of virus-specific CD8+ T cells and subsequently other virus nonspecific inflammatory cells that contribute to liver disease. Importantly, a recent study shows that the long-term use of clinically relevant doses of the anti-platelet drugs aspirin and clopidogrel, administered after the onset of liver disease, in an HBV transgenic mouse model of immune-mediated chronic hepatitis and HCC, can prevent hepatocarcinogenesis improving overall survival. Platelets therefore, act as key players in the pathogenesis of HBV-associated liver cancer supporting the notion that immune-mediated necroinflammatory liver disease is sufficient to trigger HCC and that interference with platelet activation may have clinical implications for HCC prevention.