The body has many systems that react to various situations as a means of protection and maintaining functions. For example, the body produces antibodies to fight off infection from foreign substances such as bacteria. However, some conditions cause the body to mistake an organ for a foreign body and it creates antibodies that attack a healthy organ like the thyroid. This type of condition is known as an autoimmune disease.
Anatomy
The thyroid is a small, butterfly-shaped organ located in the throat. The thyroid is responsible for maintaining the body's metabolism -- the system that regulates how energy is used. The thyroid creates the hormones, T3 and T4, which are directly responsible for metabolism. T3 and T4 are regulated by TSH, or thyroid stimulating hormone, also produced in the thyroid. Thyroid antibodies interfere with this process.
The presence of thyroid antibodies causes thyroiditis, which is a chronic inflammation of the thyroid. Tissue damage may also occur with thyroiditis, disrupting the normal function of the thyroid.
Types
There are several types of thyroid antibodies. LabTestsOnline.com discusses three types of thyroid antibodies and the conditions that might cause these antibodies to be at abnormal levels: Thyroid peroxidase antibodies, or TPOAb, are present in both Hashimoto's and Grave's disease. A physician may order a TOPAb if she suspects the patient is suffering from thyroid problems or if she is about to start the patient on drug therapy that may affect the thyroid. An abnormal level of thyroglobulin, another type of thyroid antibody, may indicate thyroid cancer or Hashimoto's disease. Thyroid-stimulating hormone-receptor antibody levels are present in patients with Grave's disease.
Hypothyroidism
Hypothyroidism is a condition where the thyroid does not produce enough thyroid hormone. Hashimoto's thyroiditis is the most common cause of hypothyroidism, according to MayoClinic.com. This disease is characterized by weight gain, fatigue, goiter, dry skin, intolerance to cold, hair loss and constipation. Depression, a puffy face and hoarse voice may also be symptoms of Hashimoto's disease.
Hyperthyroidism
Hyperthyroidism is when the thyroid produces too much thyroid hormone. Grave's disease is the most common form of hyperthyroidism. Antibodies attack the thyroid, which then produces too much thyroxine, the hormone responsible for increasing the metabolic rate. Symptoms include sweating, rapid heart rate, anxiety, tremors, fatigue, and difficulty sleeping. The patient may describe rapid weight loss without trying. The person may have protruding eyes.
Tests
Blood tests are available to measure the amounts of specific thyroid antibodies. There are no special preparations necessary before having the blood drawn -- the patient can eat and drink normally. The patient should continue taking all medications as prescribed unless a physician directs otherwise. Thyroid antibody tests are usually used to diagnose an autoimmune thyroid disease.
Treatment
Thyroid hormone treatments are available to treat the effects of thyroid disorders. Hashimoto's disease is treated with the synthetic thyroid hormone, levothyroxine. Patients with Grave's disease are put on a regimen of beta-blockers and anti-thyroid medications.
