An Antibody Test for Hyperactive Thyroid Function?

The Thyroid & Graves’ Disease

The thyroid gland is one of the organs of the endocrine system that is located in the front of the neck anterior to the trachea. This gland produces a hormone called thyroxine, which is responsible for controlling the organs and cells of the body that deal with metabolism. Thyroxine is produced in response to the presence of thyroid stimulating hormone released from the pituitary gland. If too much thyroxine is produced, then the signs and symptoms that result are called hyperthyroidism, and if too little thyroxine is produced, the symptoms and signs for this medical condition are known as hypothyroidism. Another term for hyperthyroidism is hyperactive thyroid.

When a hyperactive thyroid occurs the body’s metabolism goes into overdrive. All of the cells and bodily processes are sped up to a critical level. The person will feel nervous and irritability, have tremors, and an increased heart rate. There will be weight loss and they can have problems sleeping. A hyperactive thyroid usually results in the condition called Graves disease.

Why Is The Test Ordered?

The antibody test for hyperactive thyroid is ordered to check if a person has Graves disease. Graves disease is an autoimmune disorder in which the person’s immune system will attack his or her own cells. Normally the white blood cells will produce antibodies to foreign intruders such as bacteria and viruses, but in Graves disease, there are antibodies produced against the thyroid gland. The hormone and antibody tests for Graves disease include testing the level of thyroxine 3 (T3) hormone, thyroxine 4 (T4) hormone, thyroid stimulating hormone (TSH), and thyroid stimulating immunoglobulin (TSI). The Graves disease antibody test is the TSI test, and it measures the level of stimulating TSH receptor antibodies.

Another reason why the antibody test for hyperactive thyroid is ordered is in the case of immunosuppression treatment. If the person is being treated and the physician is hoping the autoimmune response has decreased, testing the TSI level is a great way of discovering the effectiveness and the person’s response to treatment.

Discussion On Antibody Blood Test Results

The test is performed after removing a sample of blood from the person’s arm, and analyzed to detect the level of antibodies to the thyroid stimulating hormone receptors. Most laboratories will have the normal value of the TSI antibody test for hyperactive thyroid should be at a level below 130%. However, even though the normal level should be below 130%, a patient without a hyperactive thyroid gland is not expected to have blood antibodies or have an immunoglobulin level below 2%. Someone with a blood value between 2% to 130% will most likely not have signs and symptoms of hyperthyroidism until the level reaches above the threshold. During treatment levels are expected to decrease below 130% to confirm if treatment is effective.

References

Web Source: American Association for Clinical Chemistry. “Thyroid Antibodies.” 2010. Available at: https://www.labtestsonline.org/understanding/analytes/thyroid_antibodies/test.html

Web Source: Melissa Breedlove, Davidson College. “Graves Disease. 2000. Available at: https://www.bio.davidson.edu/Courses/Immunology/Students/Spring2003/Breedlove/GravesDisease.html