Immunofluorescence detection of new antigen - antibody system ( S / anti - 5 ) associated to hepatitis B virus in liver and in serum of HBsAg carriers

A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed 3, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and 6 antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the antigen could be identified under the electron microscope. 8 antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera.