Immunohistologic demonstration of hepatitis B viral antigens in liver with reference to its significance in liver injury.

Indirect immunoperoxidase stainings for hepatitis B core and surface antigens (HBc&s Ag) were applied to formalin-fixed paraffin sections in 113 liver specimens from 56 patients. Many cytomorphologic staining characteristics of HBc&s Ag were illustrated, and the percentages of the cellular population positive for HBc&s Ag were estimated for all specimens in order to provide the basis for general analyses. The quantitative expressions and the topographic distribution of HBc&s Ag were assessed with respect to their significance and implication in histopathologic reactions. A definitive relationship or relevance was neither established nor completely excluded due to the size of samples. However, cytomorphologically the membranous expression of HBc&s Ag was shown often in association with acute lobular hepatitis and chronic active hepatitis. This observation supports the concept that the membranous expression may be the prerequisite for immune mediated hepatitic injury in viral hepatitis. In this study we also carried out indirect immunoferritin and immunoperoxidase electron microscopy for HBc&s Ag on formalin-fixed liver specimens. The results assured the validity of the light microscopic immunohistologic procedures. The immunoelectron microscopy confirmed the presence of core antigen in the Dane particles formation that takes place in the cisternae of endoplasmic reticulum. The significance of the cytoplasmic core antigen and the possible role of immunoelectron microscopy in the elucidation of mechanisms of hepatitic injury were discussed.