A positive Hepatitis B core antibody (HBcAb or anti-HBc) test indicates that a person may have been exposed to the hepatitis B virus (HBV). This antibody doesn't provide protection or immunity against HBV.
Understanding HBcAb
HBcAb is an antibody that the body produces in response to the hepatitis B core antigen (HBcAg). The presence of HBcAb in a person's blood suggests past or present infection with HBV.
Implications of a Positive HBcAb Test
A positive HBcAb test result can mean different things, so it's usually interpreted along with other hepatitis B serological markers.
Here's a breakdown of possible scenarios:
- Past HBV Infection: A positive HBcAb along with a positive Hepatitis B surface antibody (HBsAb) typically indicates that the person had a hepatitis B infection in the past and has recovered. The HBsAb suggests immunity.
- Chronic HBV Infection: A positive HBcAb along with a positive Hepatitis B surface antigen (HBsAg) indicates chronic HBV infection. In this case, the person is still infected and can transmit the virus to others.
- Resolved Infection with Loss of HBsAb: It's possible to have a positive HBcAb without HBsAb. This might indicate a resolved infection where the HBsAb has waned over time.
- "Core Window": In rare cases, a positive HBcAb may be the only marker present during the "core window" period, which is the time between the disappearance of HBsAg and the appearance of HBsAb.
- Occult HBV infection: A positive HBcAb result may indicate an occult HBV infection, where the virus is present at very low levels and HBsAg is undetectable.
Importance of Further Testing
Because the interpretation of a positive HBcAb result depends on other hepatitis B markers, further testing is crucial to determine the person's infection status, whether it's a past, resolved, chronic or occult infection.
Summary
| Test Result | Meaning |
|---|---|
| Positive | May indicate past or present infection with the Hepatitis B virus (HBV). |
