From the Guidelines
To check for hepatitis B immunity, the antibody that is tested is hepatitis B surface antibody (anti-HBs or HBsAb), with a level of anti-HBs greater than or equal to 10 mIU/mL indicating immunity to hepatitis B virus infection. This is based on the most recent and highest quality study available, which provides clear guidelines for the interpretation of hepatitis B serologic test results 1.
Key Points
- The presence of anti-HBs is generally indicative of immunity to HBV infection, and this can be achieved through either successful vaccination or recovery after a natural infection.
- The test for anti-HBs is typically performed as a quantitative assay, measuring the exact level of antibodies present in the blood.
- For individuals who have been vaccinated against hepatitis B, testing for anti-HBs can confirm whether they have developed adequate protection, and if levels are found to be insufficient after a complete vaccination series, additional booster doses may be recommended 1.
- It's also important to note that anti-HBs can be detected for 4–6 months following HBIG administration, and persons who recover from natural HBV infection are typically positive for both anti-HBs and anti-HBc, whereas persons who respond to HepB vaccine are positive only for anti-HBs 1.
Clinical Considerations
- The interpretation of serologic test results for hepatitis B is crucial for determining the immune status of an individual and for guiding further management and prevention strategies.
- A thorough understanding of the different serologic markers, including HBsAg, anti-HBc, and anti-HBs, is necessary for accurate interpretation of test results and for providing appropriate patient care 1.
From the Research
Hepatitis B Immunity
To determine hepatitis B (HB) immunity, the following antibody is checked:
Significance of Anti-HBs
The presence of anti-HBs is recognized as a protective immune marker, indicating both HBV infection clearance and immunity following vaccination 4. It is also considered an important indicator of functional cure for chronic hepatitis B (CHB) 4.
Testing for HBV Immunity
Testing for hepatitis B surface antigen (HBsAg) and anti-HBs is considered the most efficient and reasonably cost-effective method to screen for hepatitis B serologic markers 2. Anti-HBs identifies those who are immune secondary to vaccination or past infection 2.
Protection Against HBV Infection
The presence of anti-HBs in addition to hepatitis B core antibody (anti-HBc) confers protection against HBV infection in HBsAg-negative patients undergoing kidney transplantation 5. A significant difference in HBV infection rate was found between anti-HBc(+)/anti-HBs(+) and anti-HBc(+)/anti-HBs(-) groups 5.
Regulation of Anti-HBs Response
The regulation of the neutralizing anti-HBs antibody response is restricted to the presence of T helper cells, but not to identical HLA class II molecules 6. Allogeneic T cells derived from vaccine recipients or chronic HBV carriers can stimulate the HBs-specific B cell response in HBs vaccine recipients 6.