Hepatitis B x antigen and polymerase antibodies in the serum of hepatitis B carriers with or without hepatitis delta virus infection. Effects of interferon treatment.

Previous work has shown that the hepatitis B x antigen (HBxAg) and antibodies directed against the polymerase of hepatitis B virus (anti-pol) are early markers of hepatitis B virus (HBV) replication in natural infections. The present study was carried out to test the hypothesis that the appearance of one or both of these markers signaled reactivation in chronic carriers with liver disease who were treated with alpha-interferon (IFN). The results show that HBV DNA decreased among the patients who responded to therapy, and that among these responders, neither HBxAg nor anti-pol became detectable in serum for 12 months after treatment, in contrast to controls. Hence, the loss of HBxAg and anti-pol correlate with decreased levels of HBV DNA in response to IFN therapy. However, different patterns of HBxAg and anti-pol were observed among alpha-IFN-treated HBV carrier patients who were also chronically infected with the hepatitis delta virus (HDV). The treatment of such patients often resulted in the loss of HDV RNA from serum and delta antigen from liver. Most of these patients had increased levels of HBV DNA in serum. HBxAg and/or anti-pol also became detectable in patients who lost markers of HDV, implying that the suppression of HDV by IFN is accompanied by the appearance of early markers of HBV reactivation in some of the treated patients.