Table 1

Interpretation of hepatitis B serological and screening tests

Hepatitis B lab nomenclature
HbsAg	Hepatitis B surface antigen is a marker of infectivity in acute or chronic HBV infection.
HbsAb	Antibody to surface antigen is a marker of immunity and most often found in isolation in HBV immunised patients. It is also found in conjunction with HBcAb in resolved infection and rarely in isolation in naturally infected individuals.
HbcAb	Antibody to core antigen is a marker of acute (IgM), chronic (IgG) or resolved HBV infection. In the absence of HBsAg, HBcAb is generally found in conjunction with HBsAb and is a marker of resolved infection. In isolation it may represent a false positive test or indicate ‘occult’ HBV infection.
HbeAg	HB e antigen is a marker of a high degree of HBV infectivity, correlating with a high level of HBV replication. HB e antigen is absent in patients with core and pre-core mutants.
HbeAb	Antibody to hepatitis B e antigen may be present in infected or immune individuals. In persons with chronic HBV, the presence of HBeAb suggests a low level of infectivity.
HBV DNA	HBV DNA is a direct marker of HBV replication and correlates with disease activity. In blood it is used to monitor treatment. HBV may be detected in the absence of HBsAg with or without anti-HBc and when present represents active HBV infection