HEP B SURFACE ANTIBODY, QUALITATIVE

HEP B SURFACE ANTIBODY, QUALITATIVE

The presence of antibodies to hepatitis B surface antigen (anti-HBs) serves as a means to assess immunity to HBV or track disease progression in HBV-infected individuals. Measuring anti-HBs levels helps determine the necessity for vaccination or assesses the effectiveness of a vaccination regimen in establishing protective immunity.

However, the presence of anti-HBs alone doesn't definitively indicate resolved hepatitis infection or future protection from reinfection. Variations in serologic subtypes of the hepatitis B virus can lead to instances where a patient may have antibodies to one surface antigen type while being acutely infected with a different subtype, resulting in coexisting HBsAg and anti-HBs. False-positive results for anti-HBs can occur in transfused individuals or hemophiliacs receiving plasma components.

Anti-HBs typically becomes detectable several weeks to months after HBsAg clears and may persist for years or even a lifetime post-acute infection. In some cases, it may fade, leaving only antibody to the core. Patients harboring this antibody are not overtly infectious. The presence of anti-HBs in the absence of the antigen signifies immunity against reinfection by the same subtype of virus.