Expression of preS1 and preS2 in the liver of chronic hepatitis B virus carriers.

Using monoclonal antibodies we have studied the expression and distribution pattern of preS1 and preS2 proteins in the liver of 25 patients with chronic hepatitis B virus infection. Both preS1 and preS2 were detected in the liver of most cases, independently of viral replication and of the state of the viral genome in the liver. In fact, preS1 and preS2 were present in the liver of 14 out of 15 patients with HBV-DNA in the serum as well as of 7 out of 10 cases with no evidence of viral replication, including 2 with integrated HBV-DNA sequences in the liver and 5 patients with no evidence of liver damage. The pattern of distribution of preS proteins was identical to that of hepatitis B surface antigen, with exclusive cytoplasmic staining in cases without viral replication and cytoplasmic and membranous positivity in those with viral replication. These results clearly indicate that translation of preS proteins is independent of viral replication and is not necessarily associated with liver damage.