Immunoglobulins Blood Test

An immunoglobulins blood test measures the amount of immunoglobulins in your blood. Immunoglobulins are also called antibodies. Antibodies are proteins that your immune system makes to fight germs, such as viruses and bacteria.

Your body makes different kinds of antibodies to fight germs in different parts of the body and at different stages of an infection. An immunoglobulins test usually measures the three main types of immunoglobulin (Ig) antibodies that your body makes. IgM antibodies are the first immunoglobulins your body makes after you're exposed to a germ.

They provide short-term protection while your body makes other antibodies. They can be found in your blood and lymph fluid (the substance that carries disease-fighting cells throughout your body).; IgG antibodies are much more common and much more specialized. Your body creates these antibodies as a response to a specific germ and even remembers them after you've cleared the infection.

That way, if you're exposed to the same germs again, your immune system can quickly make more antibodies. Though present in all your bodily fluids, they are most commonly found in your blood.; IgA antibodies protect your respiratory tract (the organs you use to breathe) and your digestive system (the organs you use to eat and digest food) from infections. You have IgA antibodies in your blood, saliva, tears, breast milk, and respiratory and gastric fluids.;

Why this test is done

You may need this test if you have symptoms of low immunoglobulin production. One of the main symptoms of low immunoglobulin levels is frequent infections, especially repeated infections from the same germ. Other symptoms often include:

• Sinus, throat, and ear infections, especially strep throat.
• Respiratory infections, such as pneumonia and bronchitis.
• Diarrhea and/or gastrointestinal infections.
• Serious infections from germs that don't usually cause problems in healthy people, such as:
• Cytomegalovirus (a virus related to chickenpox).
• A yeast infection in the mouth, eyes, or digestive tract (thrush).

You may also need this test if immunodeficiency runs in your family, or your provider thinks you may have a problem making normal levels of immunoglobulins. Low immunoglobulin levels may be a sign of an immunodeficiency (a condition where your body's immune system can't effectively respond to an infection).

Lastly, you may need this test if your provider thinks your immunoglobulin levels are too high. Some autoimmune diseases and cancers can cause a high level of immunoglobulins. However, those immunoglobulins don't work normally.

So, even though your levels are high, you may still get frequent infections.

How to prepare

You don't need any special preparations for an immunoglobulins blood test. If you or your child is taking any medicines, be sure to tell your child's or your provider before the test. Some medicines can affect the accuracy of the results.

But don't stop taking any medicines unless your provider tells you to.

Sample type

Blood

Other names for this test

quantitative immunoglobulins, total immunoglobulins, IgG, IgM, IgA testing