Thyroid Antibodies

Also known as: Thyroid autoantibodies; Antithyroid antibodies; Antimicrosomal antibody; Thyroid microsomal antibody; Thyroperoxidase antibody; TPOAb; Anti-TPO; TBII; Antithyroglobulin antibody; TgAb; TSH receptor antibody; TRAb; Thyroid stimulating immunoglobulin; TSI

Formal name: Thyroid peroxidase antibody (TPOAb); Thyroglobulin antibody (TgAb); Thyroid stimulating hormone receptor antibody (TRAb)

Related tests: T3; T4; TSH; Thyroglobulin

The Test Sample

What is being tested?

These tests detect the presence and measure the quantity of specific thyroid autoantibodies. The autoantibodies develop when a person’s immune system mistakenly recognizes components of the thyroid as foreign (not-self) and can lead to chronic inflammation of the thyroid (thyroiditis), tissue damage, and disruption of thyroid function.

The thyroid is a small, butterfly-shaped gland that lies flat against the windpipe in the throat. The primary hormones that it produces, thyroxine (T4) and triiodothyronine (T3), are vital in helping to regulate the rate at which we use energy – our metabolism. The body has a feedback system that utilizes thyroid stimulating hormone (TSH) to help turn thyroid hormone production on and off and maintain a stable amount of the thyroid hormones in the bloodstream. When thyroid antibodies interfere with this process, they can lead to chronic conditions and disorders associated with hypothyroidism or hyperthyroidism. Hypothyroidism can cause symptoms such as weight gain, fatigue, goiter, dry skin, hair loss, intolerance to cold, and constipation. Hyperthyroidism can cause symptoms such as sweating, rapid heart rate, anxiety, tremors, fatigue, difficulty sleeping, sudden weight loss, and protruding eyes.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.