Hepatitis B virus antigens in peripheral blood mononuclear cells during the course of viral infection.

We studied the expression of surface (HBsAg) and core (HBcAg) proteins of hepatitis B virus (HBV) on the surface of peripheral blood mononuclear cells (PBMC) from HBV-infected patients. A total of 122 patients with different liver viral diseases was analyzed by indirect immunofluorescence with monoclonal antibodies. The 35 patients with HBV chronic active hepatitis (CAH) and 38 of 60 patients with acute hepatitis B (63%) expressed HBsAg on the PBMC. No expression was detected on the cells from both normal and HBV-unrelated viral hepatitis control groups. Serial follow-up of patients with acute hepatitis B showed that HBsAg expression by PBMC tended to be undetectable 4 months after the onset of the disease and at the same time the clinical improvement was evident. Cell cultures of EBV-transformed B lymphocytes were established from PBMC of HBV-infected patients; immunoelectron microscopy demonstrated the HBsAg on the cellular membrane. One-third of HBV-infected patients who were studied showed the expression of HBcAg by PBMC. HBcAg was detected in patients with acute hepatitis B at the early stage of infection. The cells of these patients also expressed HBsAg in PBMC. In CAH patients, a positive association was observed between the expression of HBcAg and the presence of serum HBeAg.