From the Guidelines
The hepatitis B surface antibody (anti-HBs) test is used to check for immunity to hepatitis B virus, and for hepatitis A, immunity can be checked with the hepatitis A total antibody test or hepatitis A IgG antibody test. A positive result (typically greater than 10 mIU/mL) in the hepatitis B surface antibody test indicates immunity, which can develop either from successful vaccination or from recovery after a natural infection 1. This test specifically detects antibodies against the surface antigen of the hepatitis B virus, which are protective antibodies that prevent future infection. For hepatitis A, the hepatitis A total antibody test or hepatitis A IgG antibody test indicates either past infection or successful vaccination, providing evidence of immunity 1.
Some key points to consider when interpreting these tests include:
- The presence of hepatitis B surface antibody (HBsAb) indicates recovery from and immunity to HBV infection, as a result of either natural infection or vaccination 1.
- Hepatitis A total antibodies or hepatitis A IgG antibody tests are used to check for immunity to hepatitis A virus, indicating either past infection or successful vaccination 1.
- There are no immunity tests for hepatitis C, D, or E, as these viruses don't confer reliable long-term immunity after infection, and only hepatitis A and B have widely available vaccines 1.
Healthcare providers typically order these immunity tests to verify vaccine response, determine if someone needs vaccination, or assess if a person has recovered from a previous infection with immunity 1. It's essential to note that the interpretation of these tests should be done in the context of the patient's clinical history and other laboratory results, as recommended by the Infectious Diseases Society of America and the American Society for Microbiology 1.
From the Research
Hepatitis Test for Immunity
The hepatitis test that checks immunity is the one that detects the presence of antibodies to hepatitis B surface antigen (anti-HBs) [ 2 ].
- Anti-HBs is used clinically to indicate an immune response to hepatitis B virus (HBV) and protection against reinfection with the virus.
- Testing for hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) is considered the most efficient and reasonably cost-effective method to screen for hepatitis B serologic markers [ 3 ].
- Anti-HBs is recognized as a protective immune marker, both for HBV infection clearance and following vaccination, and it is also considered an important indicator of functional cure for chronic hepatitis B (CHB) [ 4 ].
Interpretation of Test Results
- The detection of anti-HBs may not always signify immunity to HBV, especially in patients who have been recently transfused [ 2 ].
- Testing for antibodies to hepatitis B core antigen is needed to further distinguish between immunity due to vaccination and immunity due to past infection [ 3 ].
- The expression of serological markers in the bloodstream occurs dynamically, and the diagnosis of acute or chronic infection may be compromised if it is established based on the collection of a single sample and without knowing the patient's clinical history and their epidemiological antecedents [ 5 ].
Clinical Classification and Epidemiological Surveillance
- Hepatitis B virus surface antigen (HBsAg), IgM and IgG antibodies to hepatitis B virus core antigen (anti-HBcIgM and anti-HBcIgG) comprise serological markers of hepatitis B virus (HBV) infection of great importance in the epidemiological surveillance of hepatitis B [ 5 ].
- The detection of HBsAg and anti-HBcIgM in serum is used in the diagnosis of acute hepatitis B virus infection after recent exposure [ 6 ].