What Is IgA Test?
The Immunoglobulin A (IgA), an antibody that plays a crucial role in the immune system. IgA is found in mucous membranes lining the respiratory and gastrointestinal tracts, as well as in saliva, tears and breast milk. This test is commonly used to evaluate immune function, diagnose autoimmune diseases and detect infections.
Doctors recommend an IgA test to check for immune deficiencies, celiac disease, chronic infections and inflammatory conditions. Low levels of IgA can indicate immune system disorders, while high levels may be associated with chronic infections, autoimmune diseases or liver conditions. This test is particularly helpful for diagnosing conditions such as selective IgA deficiency, which can make individuals more susceptible to infections. Additionally, the IgA test may be ordered alongside other immunoglobulin tests (IgG and IgM) to provide a comprehensive assessment of immune function.
How is the Test Performed?
Sample Collection
The test requires a blood sample drawn from a vein of the patient.
Lab Testing
The blood sample is sent to a laboratory, where it is analyzed using techniques like nephelometry or enzyme-linked immunosorbent assay (ELISA) to measure IgA levels.
What are the symptoms that prompt this test?
The following symptoms or conditions may prompt a healthcare provider to order an IgA test:
Adults
- Recurrent infections (respiratory, sinus or gastrointestinal)
- Chronic diarrhea or digestive issues
- Unexplained weight loss or fatigue
- Skin rashes or autoimmune symptoms
- Persistent infections or weakened immunity
- Chronic liver or kidney disease
Children
- Frequent infections or failure to thrive
- Digestive problems or malabsorption
- Delayed growth or development
What are Normal Ranges for This Test?
- Men – 60 ~ 400 mg/dL
- Women – 70 ~ 400 mg/dL
**The above mentioned range is for information purpose only. Normal levels are dependent on how the test is conducted. Result interpretation should be done by a qualified doctor or healthcare professional.**
What Happens if Test Results Show Abnormal Levels?
If the IgA test results are abnormal, your healthcare provider will investigate the underlying cause. Low IgA levels may indicate IgA deficiency, celiac disease or chronic infections, while high IgA levels may suggest autoimmune disorders, liver disease or multiple myeloma. The doctor may recommend additional tests, such as:
- IgG and IgM tests (to evaluate other immunoglobulins)
- Celiac disease panel (to check for gluten intolerance)
- Liver function tests
- Bone marrow biopsy (if multiple myeloma is suspected)
Treatment options will depend on the specific conditions diagnosed. For example, patients with IgA deficiency may need preventive antibiotics, while those with celiac disease may require a gluten-free diet. Regular monitoring may also be advised to track progress and manage symptoms.
