Reference Range

Non-Reactive (reported as Reactive or Non-Reactive)

INTERPRETATIVE GUIDELINES FOR HEPATITIS B SURFACE ANTIGEN (HBsAg) TESTING:

Interpretations of HBsAg screening tests are based on Index Values:

Non-Reactive:  Index values < 1
Reactive:           Index values > 50
Reactive, but require confirmation testing:  Index values > 1 and < 50.

Non-Reactive Results:   Please evaluate the risk for your patient with the following considerations:

• If this test was performed during the “window period”, which is approximately 24 to 30 weeks post infection for Hepatitis B Virus, the results could be non-reactive.  During this time, the Hepatitis B Surface antigen is not detectable in the patient.  Testing for Hepatitis B Core IgM antibodies may be warranted.
• A non-reactive test result does not exclude the possibility of exposure to or infection with Hepatitis B Virus.  Current methods of detection may not detect all potentially infected individuals.  A non-Reactive test in an individual with prior exposure to Hepatitis B is possible if:

  Antigen levels are below the detection limit of the assay.
  Lack of reactivity of the antigen to the antibody in this assay
  Infected with mutant strain of virus which may not be detectable by this assay.

Repeat testing or viral load testing may be warranted in these patients.

Reactive Results, Not Confirmed: Samples which are initially reactive which do not confirm by neutralization testing are likely to contain cross-reactive antibodies from other infectious or immunologic disorders.  Repeat testing may be indicated at a later date if clinically indicated.

Reactive Results:  Patient is considered positive for HBsAg.  This serologic marker is associated the HBV replication and infectivity.  Interpret these results in conjunction with other HBV serologic markers.  Mandatory reporting of these results to the Department of Public Health is required under Title 17 of the California Code of Regulation.