Thyroid peroxidase (TPO) is an enzyme that is critical for to thyroid hormone synthesis in the thyroid gland. Thyroid peroxidase (TPO) antibodies bind to and block the action of TPO, resulting in decreases in thyroid hormone levels. The presence of TPO antibodies in the blood is abnormal and usually indicates thyroid disease. The thyroid peroxidase (TPO) antibodies test is usually ordered after thyroid abnormalities have been detected with some other type of testing, such as TSH and free T4. It is usually ordered with thyroglobulin antibody testing.

Function:

Thyroid peroxidase (TPO) is an enzyme expressed mainly in the thyroid that frees iodine for its addition onto thyroglobulin tyrosine residues for the production of thyroxine (T4) or triiodothyronine (T3), thyroid hormones. Some TPO antibodies may lyse thyroid cells or inhibit TPO enzyme activity, in vitro [2, 7] but in general it is considered an antibody response to thyroid damage inflicted by T-Cells.

Antibodies Appear:

Autoimmune Thyroid Disease [1, 3, 5, 6]

Graves’ Disease (an immune system disorder that results in the overproduction of thyroid hormones) [3]

Hashimoto’s Thyroiditis (can cause your thyroid to not make enough thyroid hormone.)[2]

Vitiligo [a chronic (long-lasting) autoimmune disorder that causes patches of skin to lose pigment or color.] [3, 4]

Known Cross-Reactions:

- Thyroglobulin, [9]

- gliadin, [10]

- Helicobacter pylori, [11]

- heat shock protein [12]

The measurement of thyroid stimulating autoantibodies, in conjunction with other clinical and laboratory findings, is used as an aid in the diagnosis of patients suspected of having Graves' disease.

Thyroid stimulating hormone (TSH) is one of the most important hormones currently used to diagnose thyroid abnormalities. This glycoprotein is secreted by the pituitary and stimulates release of thyroxine (T4) and triiodothyronine (T3) from the thyroid gland.

TSH release from the pituitary is controlled by thyrotropin releasing hormone (TRH) stimulation and negative feedback from free T3 and free T4.

The Thyrotropin Receptor Ab test detects the autoantibody that's associated with Graves' disease. An antibody is a specialized protein made by your immune system. Antibodies are custom made to kill pathogens in your body, such as viruses or bacteria.

Thyrotropin is also called thyroid-stimulating hormone, or TSH. TSH binds to receptors on the thyroid gland to tell it to produce thyroid hormone. The thyrotropin receptor antibody mimics TSH, so when it's present, it directs the thyroid to keep releasing hormone when your body doesn't need it. That results in high levels of thyroid hormones, which is what causes symptoms. If the thyrotropin receptor antibody is present, it's an indicator of Graves' disease.

Thyroid-binding globulin (TBG) is produced in the liver and is the primary circulating (transport) protein that binds thyroid hormones3,5,3’-triiodothyronine (T3) and thyroxine (T4) and carries them in the bloodstream.

Thyroid-binding globulin (TBG) is produced in the liver and is the primary circulating (transport) protein that binds thyroid hormones3,5,3’-triiodothyronine (T3) and thyroxine (T4) and carries them in the bloodstream.

Tiglylglycine is a marker for mitochondrial dysfunction. Mutations of mitochondria DNA may result from exposure to toxic chemicals, infections, inflammation, and nutritional deficiencies.

SOURCES:

Found in manufacturing, food, packaging, solder, bronzing, dyeing textiles, plastics, PVC pipes, fungicides, toothpaste, perfume, soap, food additives, electronic, cigarette aerosol, and dyes. Naturally present and rocks and nearby air, water, and soil. Seafood is the primary route of human exposure to tin compounds. Tin is found in both organic and inorganic forms. Inorganic tin is generally regarded as safe by the FDA as a food additive for human consumption.

Nutrient interactions:

Tin disturbs copper, zinc, and iron metabolism.

SOURCES:

Found in manufacturing, food, packaging, solder, bronzing, dyeing textiles, plastics, PVC pipes, fungicides, toothpaste, perfume, soap, food additives, electronic, cigarette aerosol, and dyes. Naturally present and rocks and nearby air, water, and soil. Seafood is the primary route of human exposure to tin compounds. Tin is found in both organic and inorganic forms. Inorganic tin is generally regarded as safe by the FDA as a food additive for human consumption.

Nutrient interactions:

Tin disturbs copper, zinc, and iron metabolism.

Hair Tin (Sn) levels have been found to correlate with environmental exposure. Depending on chemical form, Sn is a potentially toxic element. Inorganic Sn has a low degree of toxicity, while organic Sn has appreciable toxicity. Inorganic Sn is used as flame-proofing treatment in textiles, as a wood preservative, and has various uses in the glass industry. Sn is also used in tin plate electrolysis for Sn alloy coatings.

Urinary tin (Sn) provides an indication of recent or ongoing exposure to the metal, and endogenous detoxification to a lesser extent. Sn has no known physiological function in the body. Inorganic Sn has a low potential for toxicity, while organic Sn may have appreciable toxic effects.

Metallic Sn and inorganic Sn compounds are normally found in small amounts in soil, food and air. Exposure to Sn compounds may be much higher in close proximity to hazardous waste sites. Inorganic Sn is poorly absorbed from the gut. The main source of Sn is food. Canned tomatoes, tomato products, pineapple, pears and similar fruits contain the highest concentrations of Sn. The Sn concentrations of food increase with storage in opened cans.