Before explaining the tests, here are two basic medical terms:

• Antigen - this is a substance that sets off an alarm in your body to 
  protect itself (e.g. hepatitis B virus)
• Antibody - this is produced by the body to protect itself from an 
  antigen. Antibodies bind to and often inactivate antigens.

Common Blood Tests for Hepatitis B Infection

HBsAg (hepatitis B surface antigen) - This is 
the outer surface of the hepatitis B virus that 
triggers an antibody response. HBsAg 
"positive" or "reactive" means that the person 
is infected with HBV and can potentially pass it 
on to others who are in close daily contact.

HBsAb (hep B surface antibody) - The 
presence of antibodies indicates that a person 
has been exposed to HBV, but successfully 
cleared the virus from their body and is no longer contagious to others. The 
antibody protects the body from any future exposure to HBV infection - a 
person has been "naturally immunized". Antibodies are also produced from 
the HBV vaccine series.

Anti-HBc (antibody to hepatitis B core) - This test is used to identify a past or 
present HBV infection. It is produced during and after acute HBV infection. The 
core antigen is part of the hepatitis B virus and the antibody to the core antigen  
is usually present in chronic carriers. However, if it is present with a "positive" 
anti-HBs (protective antibodies), then it is associated with recovery from an 
infection and this person is not a carrier. The interpretation of this test depends 
on the first two test results.

E-Antibody - Carriers who stop producing e-antigen sometimes 
produce e-antibodies. The clinical signficance of this result is uncertain.

Liver Function Tests (or Liver Enzymes) - Includes blood tests that 
assess the general state of the liver and biliary system. When elevated 
above normal values, the ALT (alanine aminotransferase) and AST 
(aspartate aminotransferase) tests indicate damage to liver cells. The 
ALT and AST are enzymes that are located in liver cells and leak out into 
the bloodstream when liver cells are injured.

AFP (Alpha-FetoProtein) - This is a normal protein produced in the 
devloping fetus. Pregnant women will have elevated AFP's. Other adults, 
however, should not have much AFP in their blood. In a chronic carrier, 
high levels of AFP could indicate the possibility of liver cancer since this 
kind of tumor produces AFP.

Ferritin - Iron is stored in the liver in the form of Ferritin. Increased levels 
of Ferritin means there is a high iron storage. This could result from an 
increased iron intake in the diet (vitamin supplements, food cooked in iron 
pots, etc.). An elevation can also occur from a destruction of liver cells 
causing leakage of Ferritin. More research is needed to understand the 
relationship between elevated Ferritin and liver tumors.

Visit our Glossary for additional terms.

*Positive Hepatitis B Core-Antibody Test Result (HBcAB+)

1. May be recovering from acute HBV infection
2. May be distantly immune and test not sensitive enough to detect  low 
    level of anti HBs in serum
3. May be susceptible with a false positive anti-HBc
4. May be undetectable level of HBsAg present in the serum and the 
    person is actually a carrier

Please Note: The interpretation of  each  individual's results should 
receive expert evaluation. Unusual results do occur and the above is 
actually an "average" representing the most likely interpretation. The 
chart above is provided as a guide for the general public; it is not intended 
as personal medical advice. All individuals are strongly encouraged to 
consult their own health care provider to evaluate their blood test results.