What it measures
A protein from the core of the hepatitis C virus. It is in the blood while the infection is current. It can be used in place of an RNA test to check for current infection.
Why people test it
- Checking for current infection after a positive antibody test.
- Checking for a recent infection, as the antigen can appear before antibodies do.
- Checking whether the virus has gone after a course of antiviral medicine.
Typical range
There is no single range. The result is reported as detected or not detected, and some labs also give a level. The cut-off depends on the lab's method, and 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.