Hepatitis A blood tests check for immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. An IgG-positive and IgM-negative result may suggest immunity to hepatitis A. A doctor may request a ...

Your doctor will likely measure your IgE levels if you have a blood test to check for allergies. Doctors often measure IgA, IgG, and IgM together to get a snapshot of your immune function.

Illustration of the five major antibody (immunoglobulin) types: IgG, IgE, IgD, IgM, and IgA, each with its unique structural configuration and functional properties. Image Credit: gritsalak ...