Apoptosis and viral hepatitis

Viral hepatitis is a diffuse inflammatory reaction of the liver caused by hepatotropic viruses. Pathomorphologic studies have shown acidophilic bodies and hepatocyte dropout, features that are compatible with apoptosis. Using in situ terminal transferase labeling, the number of hepatocytes showing features of apoptosis in patients with chronic hepatitis B and C was found to be small but higher than healthy subjects, indicating that apoptosis is involved in the pathogenesis of these diseases. There is evidence that the immune (cytotoxic T lymphocyte)-mediated pathways of apoptosis are activated, suggesting that the apoptosis of liver cells may at least in part be related to the host immune defense. Whether other cytokine-mediated and cellular constitutive apoptotic pathways are involved or not remains to be studied. There are recent data suggesting that hepatitis B and C viral proteins may modulate apoptosis. The exact role of these observations in relation to pathogenesis remains to be established.