Immunoglobulin M Test

An immunoglobulin test measures certain immunoglobulins, or antibodies, in the blood against antigens. These antibodies are made by our body's immune system to fight against antigens, such as bacteria, viruses, and toxins. Our body produces different immunoglobulins to combat different antigens, namely IgA, IgM, IgG, IgD, IgE. The Immunoglobulin M (IgM) antibody is found mainly in the blood and lymph fluid. It is the first antibody our body creates to fight a new infection. The test is required to be taken when a person shows symptoms of an immunoglobulin deficiency. These are recurrent infections, especially of the respiratory tract (sinus, lungs) or gastrointestinal tract (stomach, intestines).

The test is commonly done via taking a blood sample from a vein. But if there is abnormal or excessive immunoglobulin production associated with the condition, then a urine sample is also needed. Another way to take this test is giving a sample of what’s called as cerebrospinal fluid (CSF). It involves drawing spinal fluid from the back. No other special preparations are required for doing this test. Although, it would be better if you go wearing a T-shirt when giving the blood sample as it becomes easier for the technician to draw blood or spinal fluid from your back.

The test is useful for detecting or monitoring of monoclonal gammopathies. This test can be ordered for a person who has signs of chronic inflammation or chronic infection. The IgM test will determine if an infection is present and whether the infection is acute or chronic. It is one of the tests to help diagnose immunodeficiency. IgM is the primary antibody fighting against A and B antigens on red blood cells. It is also responsible for blood-clotting reaction during blood-transfusion from wrong donors. Increased IgM is associated with Waldenström's macroglobulinemia, infectious mononucleosis, viral infections, nephrotic syndrome.

The skin surface is cleaned with antiseptic if the blood is being drawn from a vein. A health professional usually draws the blood by inserting a needle into a vein. The blood is withdrawn and collected in a vial or syringe. In case of the test needing to draw spinal fluid for the CSF method, the patient is asked to lie on the side with their knees pulled up to their chest. The technician then gives a shot on the back to numb any pain before inserting a hollow needle between the two vertebrae in the lower spine to remove small amounts of fluid.