Hepatitis B viruses (HBV) are DNA viruses that have a specific tropism, or affinity, for liver tissue. Detection and identification of hepatitis viruses is performed by histologic, serologic, or molecular diagnostic methodologies. Histology is essential in assessing the course and progression of hepatitis infections. Hepatitis viruses infect hepatocytes and histological findings can provide distinction of the viral hepatitides from one another and from hepatitis due to other etiologies, such as drug toxicity, autoimmune diseases, and metabolic disorders. Haematoxylin and eosin (H&E) staining alone makes it very difficult to assess the infection and requires the use of IHC to render diagnosis. Hepatitis B infection does not necessarily kill the hepatocytes.
Two hepatitis B antibodies used in IHC are hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg). Descriptions and images of each are discussed on the following pages.