Liver sections from 18 patients positive for hepatitis B surface antigen (HBsAg), and from 12 negative patients, were examined for the presence of hepatitis B virus (HBV) DNA using an in situ hybridization assay that would identify only those hepatocytes containing more than 10 to 15 HBV genome equivalents per cell. Such cells are likely to be undergoing active viral replication, rather than latent infection. The findings were correlated with results of tissue immunofluorescence for HBV antigens and the presence of serum hepatitis B e antigen (HBeAg), together with histologic assessment of each liver. HBV DNA detected in the above assay was predominantly cytoplasmic; it was associated with the presence of hepatitis B core antigen (HBcAg) in hepatocytes and HBeAg in serum, and to a lesser extent with cirrhosis and immunosuppression, but not with the presence of HBsAg in hepatocytes, nor with histological evidence of disease activity judged by the presence of piece-meal necrosis and lobular and portal tract inflammation. These findings support the view that liver HBcAg and serum HBeAg are markers of virus replication, and demonstrate that active liver disease in HBsAg-positive patients may occur with or without such markers of replication. It is proposed that alternative mechanisms for hepatocyte injury may apply in different chronic HBV patients, one related to virus replication and one dependent on immunological factors.
A variety of hepatitis B virus (HBV)-specific markers have been proposed for the diagnostic and prognostic assessments of patients with HBV infection. These can be classified into: (i) markers of HBV virions in serum [HBV-specific DNA polymerase, HBV DNA, hepatitis B core antigen (HBcAg), or direct demonstration of virions by electron microscopy (1-6)]; (ii) patterns of expression of HBcAg and hepatitis B surface antigen (HBsAg) in liver biopsies (7-9); (iii) the presence of free or integrated HBV DNA in liver extracts (2, 10, ll), and (iv) the presence in serum of hepatitis B e antigen (HBeAg) (1- 5, 10-12). Serum HBV virion markers and HBeAg, free