Immunoglobulin A (IgA)
Immunoglobulin A (IgA) is an antibody found mainly in the linings of your respiratory and digestive tracts and in secretions like saliva. This test measures the total IgA level in your blood.
Because IgA is a frontline defender at mucosal surfaces, and its level can reveal clues about immune function, recurrent infections, or certain chronic conditions. It is also important context for interpreting other tests, such as celiac antibody panels, which can be affected by IgA deficiency. Measuring it helps a clinician understand your overall immune status.
A higher-than-normal IgA can be associated with chronic infections, chronic inflammation, liver conditions, or certain immune disorders. Because many things can raise IgA, an elevated result is a prompt for your clinician to look at the broader picture rather than a diagnosis on its own.
A low IgA can reflect selective IgA deficiency, one of the more common immune deficiencies, which many people have without serious problems. Low IgA also matters because it can affect the accuracy of some IgA-based tests, so your clinician takes it into account when interpreting related results.
A result within your lab's reference range is typical. Any high or low result is best interpreted by your clinician alongside your symptoms and any related immune or celiac testing.
Sources
- Immunoglobulins (IgA, IgG, IgM) Blood Test · MedlinePlus
- Immunoglobulins Blood Test · Cleveland Clinic
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.