Blood Tests for Diagnosing Hepatitis B

TWiV 1163 Hepadnaviridae in the heartland 1The “Hepatitis B Panel” of Blood Tests*

Only one sample of blood is needed for a hepatitis B blood test with the “Hepatitis B Panel” that includes three parts. All three test results are needed to fully understand a person’s hepatitis B status**.

Below is an explanation of the 3-part “Hepatitis B Panel” of blood test results. 

 

  1. HBsAg (Hepatitis B surface antigen) - A "positive" or "reactive" HBsAg test result indicates that a person is infected with hepatitis B. This test can detect the presence of the hepatitis B virus (called the “surface antigen”) in the blood. If a person tests “positive,” then further testing is needed to determine if this is a new “acute” infection or a “chronic” hepatitis B infection.
  2. anti-HBs or HBsAb (Hepatitis B surface antibody) - A "positive" or "reactive" anti-HBs (or HBsAb) test result indicates that a person is protected against the hepatitis B virus. This protection can be the result of receiving the hepatitis B vaccine or successfully recovering from a past hepatitis B infection. A positive anti-HBs (or HBsAb) test result indicates that a person is “immune” and protected against the hepatitis B virus and cannot be infected.
  3. anti-HBc or HBcAb total (Hepatitis B core antibody) - A "positive" or "reactive" anti-HBc (or HBcAb) test result indicates that a person has been exposed to the hepatitis B virus at some point during their life. A positive HBcAb test alone cannot tell if a person has a past or current hepatitis B infection. The core antibody does not provide any protection against the hepatitis B virus (unlike the surface antibody described above). This test can only be fully understood by knowing the results of the first two tests (HBsAg and anti-HBs). A positive anti-HBc (or HBcAb) test result requires talking to a knowledgeable health care provider for a complete explanation of your hepatitis B status.

* Not all of the above blood tests are routinely performed as part of blood donation screening. If you test positive for any of these tests, please see your health care provider for advice!

**If you are in the U.S., ask your doctor to test you for hepatitis B. The U.S. Centers for Disease Control and Prevention (CDC) now recommends that all adults 18 and older be screened at least once in their lifetime. You can read more about it here.