Serum IgA (Immunoglobulin A) concentration

What Does IgA Serve in the Body?

IgA is the most abundant antibody in your body and plays a critical role in immune defense. It primarily circulates in bodily fluids like saliva, tears, mucus, and breast milk, where it helps prevent harmful microbes from entering your body through surfaces like your skin and digestive tract. IgA also plays a role in reducing inflammation and protecting against chronic infections.

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 or diagnose infections where IgA antibodies are relevant.

Common Reasons for Testing

Common reasons for measuring IgA include diagnosing immune deficiencies, evaluating symptoms of recurrent infections, assessing autoimmune diseases, or investigating conditions affecting the gastrointestinal tract. It can also be part of a broader immune workup.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. If you’re on blood thinners or have a history of bleeding issues, let your healthcare provider know.