Immunoglobulins Blood Test

Why this test may be ordered

• You have symptoms of low immunoglobulin production, such as frequent infections (especially from the same germ), sinus/throat/ear infections, respiratory infections, diarrhea, or serious infections from germs that usually don't cause problems in healthy people.
• Immunodeficiency runs in your family.
• Your provider thinks you may have a problem making normal levels of immunoglobulins.
• Your provider thinks your immunoglobulin levels may be too high (possible autoimmune disease or cancer).

Preparation and collection

You do not need any special preparations. Tell your provider about any medicines you or your child are taking, as some can affect accuracy. Do not stop taking any medicines unless your provider tells you to.

A health care professional will take a blood sample from a vein in your arm using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. Additionally, results can be affected by certain medicines, and abnormal levels do not always mean you have a condition that needs treatment.

Understanding results

Your healthcare provider will compare your levels of IgM, IgG, and IgA. Results can mean different things depending on your symptoms, any conditions you may have, and which immunoglobulins are high or low. An immunoglobulins blood test alone cannot diagnose any conditions.

• Low levels of one or more immunoglobulins: Low immunoglobulin levels Limitation: Low levels of one or more immunoglobulins may be caused by conditions that reduce protein in the body (kidney disease, serious burns, certain malabsorption disorders, malnutrition) or conditions that affect your ability to make immunoglobulins (complications from diabetes, kidney failure, a genetic disease such as common variable immunodeficiency disorder). Next step: Your provider will interpret these results in the context of your health and may recommend further testing to identify the underlying cause.
• High levels of one or more immunoglobulins: High immunoglobulin levels Limitation: High levels of one or more immunoglobulins may be caused by an autoimmune disease, hepatitis, cirrhosis, a chronic infection, or certain cancers (such as multiple myeloma, chronic lymphocytic leukemia, lymphoma, Waldenström macroglobulinemia). In some cancers, one type of immunoglobulin may be very high while the others are low. Next step: Your provider will interpret these results and may order additional tests to confirm a diagnosis.

• An immunoglobulins blood test alone cannot diagnose any conditions; abnormal results require further testing.
• Certain medicines can affect the accuracy of results.
• Abnormal immunoglobulin levels do not always mean you have a condition that needs treatment.

What to do next

If your results are not normal, your provider will likely order more tests to find out what is affecting your immune system. Additional tests may include a lumbar puncture, a saliva test, or a serum and/or urine protein electrophoresis test.

• What do my immunoglobulin levels indicate about my immune system?
• Do I need additional tests based on my results?
• How do my current medicines affect my test results?

Evidence source

U.S. National Library of Medicine: Immunoglobulins Blood Test