Thyroid Peroxidase Test

Medical Author: Frederick Hecht, MD, FAAP
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR

A test done to detect autoantibodies directed against thyroid peroxidase (TPO), an enzyme in the thyroid gland that is very important to the production of thyroid hormones. TPO is found in thyroid follicle cells where it catalyzes the iodination of T4 and T3 in the biosynthesis of thyroid hormones.

Autoantibodies to thyroid peroxidase (abbreviated TPOAb) are produced by the body itself. TPOAb can attack the thyroid and damage thyroid function. These antibodies are present in a high proportion (70% to 90%) of people with chronic thyroiditis. These antibodies are also present in lesser numbers of people with other thyroid diseases. Other autoimmune disorders such as Sjögren syndrome, lupus, rheumatoid arthritis, and pernicious anemia are sometimes positive for TPOAb. Small numbers (around 3%) of people may have TPOAb show no evidence of disease. The chance of having TPOAb is greater in females and increases with age.

This test goes by a confusing number of names, including thyroid peroxidase (TPO) antibody (TPOAb) test, thyroid peroxidase autoantibody test, antimicrosomal antibody test and antithyroid microsomal antibody test.

From the Doctors at MedicineNet.com

Hypothyroidism - Learn about Hypothyroidism (underactive thyroid) including causes, symptoms (such as weight gain, fatigue, and depression), diagnosis, and treatment. Source:MedicineNet Hyperthyroidism - Learn about hyperthyroidism (overactive thyroid gland) symptoms such as irritability, tachycardia, heat intolerance, increased sweating, weight gain, and more, as well as the causes, diagnosis, and treatment of hyperthyroidism. Source:MedicineNet Thyroid Nodules - Thyroid nodules can be either benign or malignant (cancerous). The majority of thyroid nodules are benign. Source:MedicineNet Read 8 more Thyroid Peroxidase Test related articles ... So Much to Do, So Little Sleep Head Injuries All Too Common in Summer Play Health Tip: The Word on Wisdom Teeth Health Tip: Make Exercise a Daily Habit New Source of Heart Stem Cells Found Health Highlights: June 23, 2008 Poorer Patients Have Poorer Survival After Cancer Diagnosis One Gene May Be Key to Myeloma Crocodile Babies Cry Out for Hatching Immune Molecule Key to Preventing Organ Rejection