Serum Immunoglobulin A (IgA) by Immunoassay

What Does IgA Serve in Your Body?

IgA is a key part of your immune system, primarily found in mucous membranes like those in your nose, throat, and digestive tract. It helps prevent harmful bacteria and viruses from entering your body through these surfaces. IgA also plays a role in protecting against infections in the respiratory and gastrointestinal systems.

Why Might Your Doctor Order This Test?

Your doctor may order an IgA test to check for immune system issues, such as low levels that could indicate conditions like immunodeficiency, certain autoimmune diseases, or digestive disorders like celiac disease. It may also be used to monitor treatment responses in patients with known IgA-related disorders.

Common Conditions Monitored or Diagnosed With IgA Tests

Low IgA levels can be associated with conditions like Common Variable Immunodeficiency (CVID) or other immune deficiencies. High IgA levels might be seen in certain infections, liver disease, or as part of an autoimmune response. This test is not typically used to diagnose infections like colds or flu, as IgA levels fluctuate during acute illness.

How Is the IgA Test Performed?

A blood sample is drawn from a vein in your arm. The blood is then processed to separate the serum, which is tested for IgA levels using an immunoassay method. This method detects specific antibodies in your blood and measures their concentration.