Review Question - QID 217116

This nurse who experiences a needlestick injury from a patient with an active hepatitis B infection did not develop disease most likely because of the presence of increased levels of hepatitis B surface antibodies.

The 3 major antigens that are used in serological testing for hepatitis B virus (HBV) infection are the surface antigen (HBsAg), the core antigen (HBcAg), and the e antigen (HBeAg). HBsAg is the most clinically important of these antigens because high levels of HBsAg indicate that there is an HBV infection, whereas high levels of anti-HBs antibody (HBsAb) indicate immunity to HBV infection via prior infection or vaccination. The type of anti-HBc antibody indicates the duration of infection such that the presence of IgM antibodies suggests an acute or recent infection whereas the presence of IgG antibodies suggests a previous exposure or chronic infection. Importantly, these may be the only positive serologic tests suggesting infection in the window period (after HBsAg decreases and before HBsAb increases). Finally, high levels of HBeAg suggest active replication and high transmissibility whereas anti-HBeAg antibodies suggest low transmissibility.

Cadet presents an overview of the serology markers in hepatitis B and how they can be used in workplace screening.

Incorrect Answers:
Answer 1: Decreased anti-HBc IgM antibodies would be seen after the acute infectious phase of HBV disease. This patient who never developed disease would never have been exposed to significant levels of HBc.

Answer 2: Decreased anti-HBs antibodies would be seen in patients who have waning immunity to hepatitis B since these antibodies are neutralizing and grant immunity through vaccination. This patient who never developed disease most likely has high levels of neutralizing anti-HBs antibodies.

Answer 3: Increased anti-HBc IgG antibodies would be seen during chronic or old resolved HBV infections. This patient who never developed infection would not have been exposed to large amounts of HBc antigen.

Answer 4: Increased anti-HBc IgM antibodies would be seen during the acute phase of HBV infection. This patient who never developed disease would not have high levels of anti-HBc antibodies.

Bullet Summary:
The presence of antibodies against the hepatitis B surface antigen provides immunity against developing hepatitis B infection.