What is the hepatitis B core antibody (HBcAb)?

The HBcAb is an antibody that is part of the virus- it does not provide protection. A "positive" or "reactive" HBcAb (or anti-HBc) test result indicates a past or present infection, but it could also be a false positive. The interpretation of this test result depends on the results of the other two tests. Its appearance with the protective surface antibody (positive HBsAb or anti-HBs) indicates prior infection and recovery. For chronically infected persons, it will usually appear with the virus (positive HBsAg).

http://www.hepb.org/patients/hepatitis_b_blood_tests.htm#que...