Interpretation of Hepatitis B Serologic Test Results
Hepatitis B serologic testing involves measurement of several hepatitis B virus (HBV)-specific antigens and antibodies. Different serologic “markers” or combinations of markers are used to identify different phases of HBV infection and to determine whether a patient has acute or chronic HBV infection, is immune to HBV as a result of prior infection or vaccination, or is susceptible to infection.
- Hepatitis B surface antigen (HBsAg):
A protein on the surface of hepatitis B virus that can be detected in high levels in serum during acute or chronic hepatitis B virus infection. The presence of HBsAg indicates that the person is infectious, except when it might be transiently positive within 30 days after a dose of hepatitis B vaccine (HepB). The body normally produces antibodies to HBsAg as part of the normal immune response to infection. HBsAg is the antigen used to make HepB vaccine. - Hepatitis B surface antibody (anti-HBs):
The presence of anti-HBs is generally interpreted as indicating recovery and immunity from hepatitis B virus infection. Anti-HBs also develops in a person who has been successfully vaccinated against hepatitis B. Among vaccine responders who completed a vaccine series, anti-HBs levels can decline over time, however the majority are still immune and will mount a response when exposed to HBV. - Total antibody to hepatitis B core antigen (anti-HBc):
Appears at the onset of symptoms in acute hepatitis B, is a measure of both IgM and IgG, and persists for life. The presence of total anti-HBc indicates previous or ongoing infection with hepatitis B virus in an undefined time frame. People who have immunity to hepatitis B from a vaccine do not develop anti-HBc. - IgM antibody to hepatitis B core antigen (IgM anti-HBc):
Positivity indicates recent infection with hepatitis B virus (<6 mos). Its presence indicates acute infection. IgM anti-HBc should be ordered only when acute HBV infection is a concern.
| Test and Result | Interpretation | Action |
|---|---|---|
| HBsAg—Positive Total anti-HBc — Positive IgM anti-HBc — Positive Anti-HBs — Negative |
Acute infection | Link to hepatitis B care |
| HBsAg — Positive Total anti-HBc — Positive IgM anti-HBc — Negative1 Anti-HBs — Negative |
Chronic Infection | Link to hepatitis B care |
| HBsAg — Negative Total anti-HBc — Positive Anti-HBs — Positive |
Resolved Infection | Counsel about HBV infection reactivation risk |
| HBsAg — Negative Total anti-HBc — Negative Anti-HBs — Positive2 |
Immune from receipt of prior vaccination (if documented complete series) | If no documentation of full vaccination, then complete vaccine series per ACIP recommendations. |
| HBsAg — Negative Total anti-HBc — Positive Anti-HBs — Negative |
Only core antibody is positive. See possible interpretations and corresponding actions: | |
| Resolved infection where anti-HBs levels have waned | Counsel about HBV infection reactivation risk | |
| Occult Infection | Link to hepatitis B care | |
| Passive transfer of anti-HBc to an infant born to an HBsAg-positive gestational parent | No action | |
| A false positive, thus patient is susceptible | Offer HepB vaccine per Advisory Committee on Immunization Practices (ACIP) | |
| A mutant HBsAg strain that is not detectable by laboratory assay | Link to hepatitis B care | |
| HBsAg — Negative Total anti-HBc — Negative Anti-HBs — Negative3 |
Susceptible, never infected (if no documentation of HepB vaccine series completion) | Offer HepB vaccine per ACIP recommendations |
1 IgM anti-HBc also might be positive in persons with chronic infection during severe HBV infection flares or reactivation.
2 Immune if anti-HBs concentration is >10 mIU/mL after vaccine series completion.
3 Anti-HBs concentrations might wane over time among vaccine responders. People with a documented, complete HepB vaccine series typically do not need to be revaccinated, except for special populations like patients on hemodialysis or health care personnel.