From the Guidelines
Hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) are the most critical markers for determining the status of hepatitis B virus (HBV) infection, with HBsAg indicating active infection and anti-HBs indicating immunity 1. When interpreting hepatitis B test results, it is essential to consider the combination of HBsAg, anti-HBs, and other markers such as anti-HBc and HBV DNA.
- HBsAg positive results indicate active infection, which can be either acute or chronic 1.
- Anti-HBs positive results typically indicate immunity to HBV infection, which can be due to vaccination or past infection 1.
- The presence of anti-HBc, with or without anti-HBs, can indicate past or current infection 1.
- HBV DNA testing can help confirm the presence of active infection and monitor treatment response 1. In clinical practice, understanding the differences between HBsAg and anti-HBs is crucial for diagnosing, treating, and preventing HBV infection, as well as for determining the risk of transmission and the need for vaccination or antiviral therapy 1. Key points to consider when interpreting hepatitis B test results include:
- A positive HBsAg result with a negative anti-HBs result indicates active infection 1.
- A negative HBsAg result with a positive anti-HBs result indicates immunity 1.
- A positive anti-HBc result without anti-HBs may indicate past infection with waned immunity or chronic infection with undetectable HBsAg 1.
From the Research
Hepatitis B Antibody and Antigen
- Hepatitis B antibody (anti-HBs) and antigen (HBsAg) are two key components in understanding hepatitis B virus (HBV) infection and immunity [ 2 ].
- Anti-HBs antibodies develop after natural infection with HBV or vaccination against this virus, and are recognized as a protective immune marker [ 3 ].
- The presence or absence of anti-HBs antibodies in the context of HBV immunity has been the subject of extensive discussion and clinical, laboratory, and epidemiological interest [ 2 ].
Role of Anti-HBs in HBV Infection
- Anti-HBs is considered an important indicator of functional cure for chronic hepatitis B (CHB), and its presence is associated with the clearance of HBV infection [ 3 ].
- The restoration of HBV-specific B cell function, along with the induction of an anti-HBs antibody response, is regarded as pivotal for terminating chronic HBV infection and achieving functional cure [ 3 ].
- Mathematical models of the antibody response following HBV infection have shown that viral clearance can be achieved for high anti-HBV antibody levels, as in vaccinated individuals [ 4 ].
Comparison of Anti-HBs and HBsAg
- HBsAg is a surface antigen of the hepatitis B virus, and its presence is indicative of active HBV infection [ 5 ].
- Anti-HBs antibodies, on the other hand, are indicative of immunity to HBV infection, either through natural infection or vaccination [ 2 ].
- The significance of antibody to hepatitis B surface antigen (anti-HBs) in infection and clearance of HBV has been extensively studied, and its role in achieving functional cure for CHB has been established [ 3 ].