Anti Microsomal Antibody Test

An antithyroid microsomal antibody test is also called a thyroid peroxidase test. It measures antithyroid microsomal antibodies in your blood. Your body produces these antibodies when cells in your thyroid become damaged. Your thyroid is a gland in your neck that makes hormones. These hormones help regulate your metabolism. Testing for thyroid antibodies, such as thyroid peroxidase antibody (TPO), is primarily ordered to help diagnose an autoimmune thyroid disease and to distinguish it from other forms of thyroid dysfunction. Your doctor may order this test along with other tests to help diagnose thyroid problems or other autoimmune conditions.

It is recommended that you should either wear a sleeve-less or a short-sleeved shirt to make it easier for you and the technician who will be drawing the blood. Wearing a shirt with full- sleeves that can easily be rolled-up is also fine. You may be asked to stop eating and drinking for 6-8 hours before this blood test.

Negative test results means that thyroid autoantibodies are not present in the blood at the time of testing and may indicate that symptoms are due to a cause other than autoimmune. However, a certain percentage of people who have autoimmune thyroid disease do not have autoantibodies. If it is suspected that the autoantibodies may develop over time, as may happen with some autoimmune disorders, then repeat testing may be done at a later date. Mild to moderately elevated levels of thyroid antibodies may be found in a variety of thyroid and autoimmune disorders, such as thyroid cancer, type 1 diabetes, rheumatoid arthritis, pernicious anemia, and autoimmune collagen vascular diseases. Significantly increased concentrations most frequently indicate thyroid autoimmune diseases such as Hashimoto thyroiditis and Graves disease.

A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit) A 70% alcohol pad is used to clean the skin A needle is then kept in line with and injected into a vein that can be seen from the skin The blood is dragged out from the needle by a nozzle, saved in a vessel and sealed with your name The sample is then taken to a lab for examination