CEA Nursing Practice Exam

If a patient had Hepatitis A about a year ago, which immunoglobulin is most likely to be elevated at this time?

1. IgD.

2. IgA.

3. IgG.

4. IgM.

The correct answer is: IgG.

In the context of a past Hepatitis A infection, the immunoglobulin that is most likely to be elevated is IgG. When an individual is infected with Hepatitis A, their immune system responds by producing various types of antibodies. Initially, immunoglobulin M (IgM) is generated as a response to the acute phase of the infection and is typically the first antibody detectable after exposure. However, after the acute infection resolves, the levels of IgM decline, and immunoglobulin G (IgG) antibodies are produced. These IgG antibodies remain elevated long after the infection has cleared, providing long-term immunity to the virus. In cases of Hepatitis A, the presence of IgG antibodies indicates that the person has been exposed to the virus and has developed immunity, making it a marker of past infection. In contrast, IgD and IgA are not primarily associated with the immune response to Hepatitis A. IgD plays a role in the activation of B cells, while IgA is primarily involved in mucosal immunity. Therefore, in someone who had a Hepatitis A infection about a year ago, elevated levels of IgG would be expected as evidence of recovery and immunity from the virus.