Thyroid Disease Antibodies That Contribute to Thyroid Disease Common Thyroid Antibodies By Mary Shomon facebook twitter linkedin Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution." Learn about our editorial process Mary Shomon Medically reviewed by Medically reviewed by Lindsey Waldman, MD, RD on November 06, 2019 linkedin Lindsey Waldman, MD, RD, is a board-certified pediatrician and pediatric endocrinologist. Learn about our Medical Review Board Lindsey Waldman, MD, RD on November 06, 2019 Print Table of Contents View All Table of Contents Autoimmune Antibodies and Thyroid Disease Antibody Test Results What Anti-Thyroid Antibodies Mean for You While there are a number of different thyroid disorders, autoimmune antibodies against the thyroid gland are among the most well-understood causes of thyroid disease. Because of this, your doctor may order thyroid antibody tests for you. These results can help identify the root cause of your thyroid disease and may factor into a treatment plan for your condition. Autoimmune Antibodies and Thyroid Disease Antibodies are proteins produced by your body to help protect you against infections. They can, however, mistakenly attack your own tissues, causing illness. The consequence is described as an autoimmune disease, and some thyroid conditions are caused by this immune system dysfunction. There are several types of thyroid antibodies, and each one attacks a different target in the thyroid hormone production process, ultimately causing thyroid disease. The most common thyroid antibodies are: Anti-thyroperoxidase (TPO) antibodiesThyroid stimulating hormone (TSH) receptor (TSHR-Ab) antibodiesAnti-thyroglobulin (anti-Tg) antibodies Anti-thyroperoxidase (TPO) Antibodies The most common thyroid antibodies attack thyroid peroxidase. Also called thyroperoxidase (TPO), this enzyme functions in the thyroid gland to help produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Autoimmune antibodies can interfere with TPO's ability to use iodine to produce these hormones, resulting in hypothyroidism. TPO antibodies cause inflammation, can eventually destroy all or part of your thyroid gland, and can also cause your thyroid gland to form nodules or to become enlarged. The presence of anti-TPO antibodies is associated with pre-term labor and with Hashimoto's thyroiditis, an autoimmune thyroid condition. Hashimoto's Thyroiditis Facts It can take time for the destructive effect on your thyroid gland to be reflected in your thyroid-stimulating hormone (TSH) level. It's not uncommon to have positive TPO antibodies for months or years before your TSH level rises to a point where you are diagnosed with hypothyroidism. It's important to mention, as well, that some people never progress to being hypothyroid, despite having positive TPO antibodies. Thyroid Stimulating Hormone (TSH) Receptor (TSHR-Ab) Antibodies TSH, a hormone released by the pituitary gland in the brain, stimulates the thyroid gland to make thyroid hormone. TSH initiates this process by binding to TSH receptors on the thyroid gland. TSH receptor antibodies (TSHR-Ab) can imitate the action of TSH, causing excess thyroid hormone production. High TSHR-Ab levels are associated with Grave's disease, an autoimmune condition that usually causes hyperthyroidism. Anti-thyroglobulin (Anti-Tg) Antibodies Thyroglobulin (Tg) is a protein that helps the thyroid gland function properly. Anti-Tg antibodies are associated with Hashimoto's thyroiditis. Antibody Test Results Antibody levels can be determined by analyzing a blood sample. Normal values are as follows: TPO antibody: The measured serum level should be less than 9 IU/mL.Anti-Tg antibody: The measured serum level should be less than 4 IU/mL.Thyroid-stimulating immunoglobulin antibody (TSI): This value should be less than 1.75 IU/L. Note, however, that normal range values may differ based on the laboratory where you are getting your test. What Anti-Thyroid Antibodies Mean for You Generally speaking, your thyroid treatment is not based on antibody levels—it is based on your symptoms and thyroid hormone levels. However, antibody tests can be useful in assessing the cause of your thyroid disease and can help identify subclinical thyroid disease. Positive thyroid antibodies suggest that you could have autoimmune thyroid disease, but they are only a piece of the picture. While they may influence the decision to move ahead with treatment, other factors in addition to your symptoms—family history, other blood test results—will be considered, too. If you have high levels of thyroid antibodies without symptoms and with normal thyroid hormone levels, your doctor is less likely to treat your thyroid disease than if you have mild symptoms or borderline abnormal thyroid hormone levels along with your elevated antibody levels. Sometimes, the presence of antibodies supports the diagnosis of subclinical hypothyroidism, which is thyroid disease with minimal symptoms or without symptoms. Early therapy for subclinical thyroid disease may prevent its progression, but this has not been validated. How to Understand Thyroid Function Tests and Normal Ranges A Word From Verywell Usually, autoimmune disease affects one or a few organs in the body. But if you have one autoimmune disease, it increases your chances of having another as well. Autoimmune thyroid disease can be associated with other conditions that are believed to have an autoimmune etiology, like diabetes and inflammatory bowel disease. Was this page helpful? Thanks for your feedback! Losing weight with thyroid disease can be a struggle. Our thyroid-friendly meal plan can help. Sign up and get yours free! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Vanderpump MP. The epidemiology of thyroid disease. Br Med Bull. 2011;99:39-51. doi:10.1093/bmb/ldr030 Fröhlich E, Wahl R. Thyroid Autoimmunity: Role of Anti-thyroid Antibodies in Thyroid and Extra-Thyroidal Diseases. Front Immunol. 2017;8:521. doi:10.3389/fimmu.2017.00521 Additional Reading Behroozi-Lak T, Akbary A, Vazifekhah S, Naghavi-Behzad M, Mirza-Aghazadeh-Attari M. Association of Hypothyroidism and Anti-Thyroid Antibodies With Preterm Delivery: A Cross Sectional Study. J Family Reprod Health. 2017 Dec;11(4):191-196. Diana T, Kahaly GJ. Thyroid Stimulating Hormone Receptor Antibodies in Thyroid Eye Disease-Methodology and Clinical Applications. Ophthalmic Plast Reconstr Surg. 2018 Jul/Aug;34(4S Suppl 1):S13-S19. doi: 10.1097/IOP.0000000000001053. Kotwal A, Stan M. Thyrotropin Receptor Antibodies-An Overview. Ophthalmic Plast Reconstr Surg. 2018 Jul/Aug;34(4S Suppl 1):S20-S27. doi: 10.1097/IOP.0000000000001052. Krátký J, Ježková J, Kosák M, et al. Positive Antithyroid Antibodies and Nonsuppressed TSH Are Associated with Thyroid Cancer: A Retrospective Cross-Sectional Study. Int J Endocrinol. 2018 Sep 6;2018:9793850. doi: 10.1155/2018/9793850. eCollection 2018.