What it measures
A protein the hepatitis B virus makes while it is actively multiplying. Its presence usually goes with high levels of virus in the blood. The result is read together with the e antibody and other hepatitis B results.
Why people test it
- Monitoring people with long-term (chronic) hepatitis B.
- Read with the e antibody and viral load to help judge how active the virus is.
Typical range
There is no numeric range. The result is reported as positive or negative (sometimes reactive or non-reactive). The report shows how that lab reports it.
Finger-prick or vein?
Providers offer this test only from a vein sample, taken at a clinic or by a visiting nurse, usually together with the e antibody.