Immunoglobulin A (IgA) Test - Immunoglobulin A (IgA) Level Test

Immunoglobulin A (IgA) is one of the five major classes of antibodies. It is found primarily in mucous membrane fluids (such as saliva, tears, and respiratory and intestinal secretions) and in blood. It plays a vital role in the "external" immune defense, preventing microbes from adhering to epithelial cells and neutralizing toxins. This test measures the concentration of IgA in serum (blood). It is used to assess systemic mucosal immunity and to diagnose immunodeficiency or diseases associated with elevated IgA levels.