Hepatitis B – Australian antigen

HBsAg (also known as the Australia antigen) is the surface antigen of the hepatitis B virus (HBV). It indicates current hepatitis B infection.

These antigen-proteins can be genetically manufactured (e.g. transgene E. coli) to produce material for a simple antigen test, which detects the presence of HBV.

It is present in the sera of patients with viral hepatitis B (with or without clinical symptoms). Patients who developed antibodies against HBsAg (anti-HBsAg seroconversion) are usually considered non-infectious. HBsAg detection by immunoassay is used in blood screening, to establish a diagnosis of hepatitis B infection in the clinical setting (in combination with other disease markers) and to monitor antiviral treatment.

In histopathology, the presence of HBsAg is more commonly demonstrated by the use of the Shikata orcein technique, which uses a natural dye to bind to the antigen in infected liver cells.

Positive HBsAg tests can be due to recent vaccination against Hepatitis B virus but this positivity is unlikely to persist beyond 14 days post-vaccination.

• Sample of blood serum
• We perform the test daily