Thyroid Antibodies
.
What are Thyroid Antibodies?
Thyroid antibodies, also known as anti-thyroid antibodies, are proteins produced by the body in response to either an infection or destruction of the thyroid gland. The three main categories of thyroid antibodies include antithyroglobulin (ATG), antithyroperoxidase (ATPO) and antimicrosomal (AMAb) antibodies. Each of these antibodies play a role in the body’s autoimmune response to a thyroid disorder, and can be used to diagnose various illnesses related to the thyroid.
Preparation for Testing Thyroid Antibodies
Thyroid antibodies tests are usually ordered by a healthcare professional as part of a comprehensive medical evaluation for someone with signs or symptoms of a thyroid disorder. These signs and symptoms may include weight gain, fatigue, depression, and changes in mood. Prior to the laboratory test, you may be asked to fast for several hours or overnight. Additionally, some laboratories may require that the sample is taken while you are standing, as opposed to lying down, in order to prevent contamination.
Types of Thyroid Antibodies
- Antithyroglobulin (ATG) – This type of antibody is produced in response to the thyroid-stimulating hormone (TSH) and attacks the thyroglobulin protein, which helps it produce thyroid hormones. Abnormal levels of ATG are indicative of autoimmune thyroiditis.
- Antithyroperoxidase (ATPO)/Antimicrosomal (AMAb) – ATPO antibodies attack the antigens located in the thyroid gland. Antimicrosomal antibodies are similar, attacking antigens in the peroxisome of the thyroid cells. Both antibodies are typically tested for Hashimoto's thyroiditis, an autoimmune disorder.
Risks Associated with Testing for Thyroid Antibodies
Testing for thyroid antibodies does not cause any radiation exposure or health risks associated with collecting a blood sample. The only risk that may be associated with testing thyroid antibodies is that of a false-positive or false-negative result, which could lead to incorrect diagnosis and treatment.
When to Test for Thyroid Antibodies?
An increased level of thyroid antibodies may indicate an autoimmune condition resulting in the destruction of thyroid tissue. Thyroid antibodies testing may be ordered when someone is suspected of having a thyroid disorder, such as Graves' disease, Hashimoto's thyroiditis, or an enlarged thyroid gland. Testing for thyroid antibodies is also helpful for monitoring the progression of an autoimmune disorder. Additionally, thyroid antibodies testing may be recommended for women with a history of miscarriage, stillbirth, or infertility, as thyroid autoantibody levels are higher in pregnant women.
Conclusion
Thyroid antibodies tests can help diagnose a thyroid disorder, allowing a doctor to determine an appropriate course of treatment. Testing for thyroid antibodies typically requires a blood sample and generally does not pose any significant health risks.If you are experiencing signs and symptoms of a thyroid disorder, it is important to speak with your healthcare provider to determine if testing for thyroid antibodies is necessary.
