Study on antibodies to hepatitis B virus (HBV) X-protein in sera from patients with chronic HBV infection and X-related protein in the liver from those patients

Abstract

Sera from HBV infected patients were tested for the presence of antibodies to HBV X-protein by Western blotting using recombinant-derived protein, and the expression of X-related protein in the liver of those patients was examined by immunohistochemical method using antibody to synthetic X protein peptide. Antibodies to X-protein were detected in 3 out of 100 sera of patients. In those three positive sera, one from an asymptomatic HBV carrier and another from a patient with chronic hepatitis were strongly positive, and the remainder serum from a patient with hepatocellular carcinoma was weakly positive. The patient with chronic hepatitis positive for antibody to X-protein was treated with interferon. Although fluctuations of transaminase levels and decrease of HBV DNA polymerase activity were observed in the patient described above, there was no significant change in titer of antibody to X-protein. In the immunohistochemical examination, X-related protein, which was observed in the cytoplasm of hepatocytes and was distributed in sporadic or focal pattern, was observed in 11 out of 41 patients. There was no statistically significant relationship between the presence of X-related protein and the HBeAg/anti-HBe system. However, two patients positive for antibodies to X-protein in sera were also positive for X-related protein in the liver.