Why It Is Done
Thyroid antibody tests are usually done if you have a goiter or symptoms of thyroid disease.
The following tests may be done:
- Antithyroid peroxidase antibody: This can show Hashimoto’s thyroiditis. It also can help your doctor tell if mild hypothyroidism is likely to get worse.
- Thyroid stimulating antibody: This can check for Graves’ disease. It also can help a doctor find out if the fetus of a mother with Graves’ disease is likely to get a short-term form of the condition.
- Anti-thyroglobulin antibody: This also is used to look for Hashimoto’s thyroiditis and to see if mild hypothyroidism might get worse. It also can be used to see if a thyroglobulin test done during treatment for thyroid cancer is accurate.
Conditions Associated With High Thyroid Peroxidase Antibodies
What does it mean if you have thyroid peroxidase antibodies floating around in your blood?
Well, it can mean several things:
- It may be a marker for the autoimmune disease known as Hashimotos thyroiditis.
- It may also be a marker for another autoimmune disease of the thyroid gland known as Graves disease .
- It may be a transient thing that may eventually go away on its own ).
The presence of thyroid peroxidase antibodies is never normal but it doesnt always guarantee a poor outcome.
For instance, as I mentioned above, some people see elevated antibodies during pregnancy which then fall after birth.
The significance of thyroid peroxidase in this exact setting is not well understood but it does give some hope that not every situation of elevated antibodies points to autoimmune disease.
Why would you want to check your thyroid peroxidase antibodies?
Your doctor can use this test in a number of useful ways:
What Are Thyroid Blood Tests And Why Are They Taken
Thyroid blood tests are used to tell if your thyroid gland is functioning properly by measuring the amount of thyroid hormones in your blood. They are done by withdrawing blood from a vein in your arm. These blood tests help to diagnose thyroid diseases.
The thyroid is a butterfly-shaped gland located in the front part of your neck. Its job is to produce thyroid hormones, which travel through your bloodstream and regulate many aspects of your bodys metabolism, including temperature, weight, and energy.
Thyroid blood tests show if you have:
- Hyperthyroidism: Overactive thyroid producing more thyroid hormones than your body needs. Hyperthyroidism speeds up your metabolism, which can cause weight loss, rapid heartbeat, insomnia, puffiness around the eyes, anxiety and other symptoms. The most common cause of hyperthyroidism is Graves disease.
- Hypothyroidism: Underactive thyroid producing too few thyroid hormones. Hypothyroidism slows down your metabolism, which can cause weight gain, menstrual irregularity, dry and puffy skin, fatigue and other symptoms. The most common cause of hypothyroidism is Hashimotos disease.
Thyroid blood tests are used to diagnose thyroid disorders associated with hyper- or hypothyroidism. These include:
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What Are Thyroid Peroxidase Antibodies
What I just described is what thyroid peroxidase does inside of the thyroid gland but this is completely different from thyroid peroxidase antibodies.
If youve been told that you have thyroid peroxidase antibodies, also referred to as TPO antibodies, then this information applies to you.
Your body creates antibodies to things that it wants to kill or get rid of.
In a healthy state, you should really never see antibodies to any part of your own body or tissues.
Because why would you want to get rid of something that is supposed to be in your own body?
Antibodies are usually created to help your body eliminate infections or viruses but they can sometimes be created by your immune system to target your own body.
When this happens you are said to have an autoimmune disease .
We can break apart the word to understand exactly what it means:
Auto , immune , and disease .
In the case of thyroid peroxidase antibodies, your own body is creating antibodies that target, damage, and destroy the thyroid peroxidase enzyme.
These antibodies are produced by the immune system and flow through your entire body until they find their target.
Once they reach their target their goal is to destroy it.
And because their target is located in the thyroid gland, your thyroid becomes the site of a war between your immune system and thyroid peroxidase.
As you might imagine, this results in damage to your thyroid gland which can become permanent if the damage is severe enough.
What Is The Thyroid Peroxidase Test
Thyroid peroxidase test is a test that measures the level of an antibody that is directed against thyroid peroxidase .
Autoantibodies to thyroid peroxidase are produced within the body. The presence of TPOAb in the blood reflects a prior attack on the thyroid tissue by the body’s immune system.
What does a positive thyroid peroxidase test mean?
Most people with chronic Hashimotos thyroiditis display a positive TPO test. The test is also positive in lesser numbers of people with other thyroid diseases.
Other autoimmune disorders that may cause a positive TPOAb test include:
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How Is The Tpo Antibodies Test Performed
TPO antibodies test is, basically, a blood test. Your healthcare provider or a lab technician will take a sample of your blood in order to measure how many antibodies are in it.
The blood sample is collected by inserting a needle into a vein in the arm. You might feel a little sting when the needle goes in or out. The whole process lasts five minutes maximum. TPO antibodies test requires no special preparations.
However, you should inform the doctor if you’re taking some medications, supplements, or herbs. Some drugs and supplements may impair the results.
Based on the information you provide, the doctor will suggest whether you can continue taking the medication or supplement even on the day of the test or not.
Follow the doctors recommendations religiously in order to get accurate results and precise diagnosis or insight into your condition.
Additional Insight From Dr Sameer Nakedar Mbbs Mrcgp Pgcert
Some vitamins and minerals support your thyroid function therefore, getting optimal vitamins helps. However, abnormal levels of specific vitamins can also cause various symptoms, sometimes similar to thyroid disorders. Understanding these vitamin and mineral levels can help identify or exclude a cause for these symptoms.
The advanced check also includes inflammatory markers. In some situations, thyroid disorders are caused by autoimmune disorders, meaning the bodys natural defence system is not functioning adequately. In some cases, thyroid disease is a result of autoimmune problems.
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Does The Tpo Test Diagnose Thyroid Disease
TPO is actually an enzyme found in the thyroid gland which plays an important role in producing thyroid hormones. When the TPO test is conducted, it can detect antibodies in the blood that can help get to the cause of thyroid disease.
If TPO antibodies are detected, doctors may suspect an autoimmune disorder such as Graves Hashimotos disease. Autoimmune diseases are characterised by antibodies produced by the immune system and then erroneously attacking normal body tissue. If this happens then tenderness, swelling and thyroid malfunction can be the result
If you are pregnant and also suffer from an autoimmune disease involving the thyroid, then your doctor will most likely order a TPO antibody test. It should be noted however, that not every person with TPO antibodies will also have thyroid disease but the presence of these antibodies is an indication of the potential for thyroid disorders in the future.
Symptoms Of Hashimotos Thyroiditis
At the very beginning, patients may not notice any particular symptom. This autoimmune condition tends to progress slowly over the years and causes thyroid damage and a decline in hormone production.
In fact, Hashimotos thyroiditis is the most common cause of hypothyroidism, which is why signs and symptoms of this autoimmune disease are similar to the underactive thyroid. Some of them include:
- Thick and red skin usually on top of feet or shins
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Why Take The Tpo Antibodies Test
TPO are antibodies that exist in the follicle cells of the thyroid gland. TPO is the most common test to detect an autoimmune disease of the thyroid gland like the Hashimoto and Graves disease.
If you have symptoms of Hashimoto Thyroiditis then, you are advised to order the TPO Antibody test. These include weight gain, fatigue, having a pale and puffy face, constipation, experiencing unexplained joint and muscle pains, having brittle hair, depression and having a slow heart rate. Since these symptoms can be similar to other health conditions, it is essential to get your TPO Antibodies tested and have the right diagnosis and treatment plan.
You need to get your TPO Antibodies tested if you experience symptoms of Graves disease that consist of a racing heartbeat, hand tremors, trouble sleeping, losing weight, feeling the muscles weak, as well as having bulging eyes. Skin symptoms can also accompany this auto-immune disease, and consist of developing a dermopathy: development of lumpy red thick skin in front of the shins.
The TPO Antibodies test is also ordered to monitor the treatment of thyroid cancer. From another angle, it is encouraged to be taken in case the person is having reproductive difficulties like miscarriages, pre-eclampsia, premature delivery and in-vitro fertilization.
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Association Of Tai And Subfertility In Women
TAI identified by the existence of thyroid peroxidase antibodies or thyroglobulin antibodies is frequently stated in subfertile women. Specifically, TPOAb has been related to lower fertilization rates and unstable embryogenesis.13
TPOAb was likely to be positive in euthyroid women having female factor infertility in comparison with fertile, age-matched euthyroid women.6 In women with polycystic ovarian syndrome , the frequency of TAI may be higher in comparison with controls.14 In subfertile women with PCOS, the existence of TAI has been correlated with a lower probability of maturing ovarian follicles with the use of clomiphene citrate for ovulation induction.15 However, other studies have failed to prove such associations. Among infertile women with PCOS, a study conducted on 436 women undergoing 530 antral follicular count measurements, no correlation was found with regard to thyroid function or TPOAb positivity with AFC.16 Conversely, the same study reported that lower free T3 and TPOAb positivity were coupled with a lower AFC in females with diminished ovarian reserve or UE infertility.16
Gregory Kline MD, Hossein Sadrzadeh PhD, in, 2017
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Defects In The Enzymes Required For Iodide Organification
Defect in the Key Enzyme Catalyzing the Iodination and Coupling of Tyrosyl Moieties Gene: TPO
Thyroid peroxidase is a thyroid-specific heme peroxidase anchored via a C-terminal transmembrane domain at the apical membrane surface of follicular thyroid cells . Using hydrogen peroxide as oxidative equivalents, TPO catalyzes the iodination of tyrosyl residues in TG and the subsequent phenoxy ether bond formation between pairs of iodotyrosines to generate iodothyronines .
The first case of CH due to failure of iodide organification in the presence of hydrogen peroxide was reported in 1950 by Stanbury et al.32 Four decades later, the human TPO gene was cloned,33 followed shortly after by the description of a TPO mutation in a patient with CH.34 Inactivating biallelic defects in the TPO gene appear to be the most frequent cause of inherited dyshormonogenesis with permanent CH35,36 and the culprit in essentially all patients with permanent total iodide organification defects .37 Bakker et al. estimated the incidence of TIOD owing to biallelic TPO defects at 1:66,000 for a Dutch population.37
Finding of TPO mutations in a neonate with CH indicates that the patient will require lifelong treatment with thyroid hormone and that future pregnancies should be carefully monitored for the presence of fetal goiter. The latter can be detected by ultrasonography and treated by a single intraamniotic injection of L-T4 to prevent goiter-related dystocia and improve neurological development.41
Types Of Thyroid Function Tests
The purpose of thyroid blood tests is to measure the thyroid gland’s function. This is done by looking at hormones and other substances produced by the thyroid gland and organs that control thyroid function.
A single test offers helpful information about your thyroid health, but it usually takes more than one test to get a complete picture.
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Can I Take The Test At Home
Test kits are available that allow patients to test for certain thyroid antibodies at home. These kits provide the supplies needed for obtaining a blood sample and returning it to the company for analysis.
Some kits include one or more thyroid antibody tests as part of a panel of thyroid tests, while others test only for TPOAb or TgAb. At-home tests for TRAb may not be commercially available at this time.
Thyroid antibody tests are difficult to interpret and may be unnecessary if other thyroid tests are normal. If an abnormal level of thyroid antibodies is detected on an at-home test, it is likely that an endocrinologist will want the test to be repeated.
In-depth information about at-home thyroid testing is available at the At-Home Thyroid Testing page.
What Are The Types Of Thyroid Antibody Tests
There are several types of thyroid antibody tests. These include the following:
Thyroid peroxidase antibody test helps detect Graves disease and Hashimotos thyroiditis.
Thyroglobulin antibody test is conducted in people with thyroid cancer or Hashimotos thyroiditis. Thyroid-stimulating immunoglobulin and Thyroid-stimulating hormone receptor antibody tests are essential for individuals with Graves disease.
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How Does The Thyroid Gland Function
The major thyroid hormone secreted by the thyroid gland is thyroxine, also called T4 because it contains four iodine atoms. To exert its effects, T4 is converted to triiodothyronine by the removal of an iodine atom. This occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. The amount of T4 produced by the thyroid gland is controlled by another hormone, which is made in the pituitary gland located at the base of the brain, called thyroid stimulating hormone . The amount of TSH that the pituitary sends into the bloodstream depends on the amount of T4 that the pituitary sees. If the pituitary sees very little T4, then it produces more TSH to tell the thyroid gland to produce more T4. Once the T4 in the bloodstream goes above a certain level, the pituitarys production of TSH is shut off. In fact, the thyroid and pituitary act in many ways like a heater and a thermostat. When the heater is off and it becomes cold, the thermostat reads the temperature and turns on the heater. When the heat rises to an appropriate level, the thermostat senses this and turns off the heater. Thus, the thyroid and the pituitary, like a heater and thermostat, turn on and off. This is illustrated in the figure below.
How Much Does The Test Cost
Thyroid antibody test costs vary based on factors such as where the test is done, whether or not you have health care coverage, how many antibodies are tested for, and whether other tests are performed along with the antibodies test.
When ordered by a doctor, insurance typically covers the test, although you may have to pay a deductible or co-pay. Your doctors office, lab, and health plan can provide information about any out-of-pocket costs that may be your responsibility.
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Medical Definition Of Thyroid Peroxidase Test
- Medical Editor: Charles Patrick Davis, MD, PhD
Reviewed on 3/29/2021
Thyroid peroxidase test: A blood test done to detect autoantibodies directed against thyroid peroxidase , 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 are produced by the body itself. TPOAb can attack the thyroid and damage thyroid function. These antibodies are present in a high proportion of people with chronic thyroiditis. These antibodies are also present in lesser numbers of people with other thyroid diseases. Other autoimmune disorders such as Sjogren syndrome, lupus, rheumatoid arthritis, and pernicious anemia are sometimes positive for TPOAb. Small numbers 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 antibody test, thyroid peroxidase autoantibody test, antimicrosomal antibody test and antithyroid microsomal antibody test.
What Is Thyroid Peroxidase Antibody
An antibody is a protective protein produced by the immune system against an antigen, a foreign substance. Antibodies help remove antigens from the body by binding to them. When antibodies attack the body cells, they produce an autoimmune response. Thyroid peroxidase antibodies prevent thyroid peroxidase from catalysing the production of thyroid hormones.
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Side Effects Of Thyroid Blood Tests And Care
Thyroid blood tests are performed after a routine blood draw. That’s when blood is drawn from you by a syringe and sent to a lab. This is a safe procedure with few potential side effects.
It’s rare, but some people get nauseous or feel faint when they have blood drawn. Let the medical personnel know immediately if you experience these side effects.
Later, you may notice a small bruise or have some tenderness at the needle insertion site. An over-the-counter pain reliever or an ice pack can help with this.
You should get medical attention if the insertion site is:
These are signs of an infection, which needs to be treated with antibiotics.
What Do The Results Mean
Your results may show one of the following:
- Negative: no thyroid antibodies were found. This means your thyroid symptoms are probably not caused by an autoimmune disease.
- Positive: antibodies to TPO and/or Tg were found. This may mean you have Hashimoto disease. Most people with Hashimoto disease have high levels of one or both of these types of antibodies.
- Positive: antibodies to TPO and/or TSH receptor were found. This may mean you have Grave’s disease.
The more thyroid antibodies you have, the more likely it is that you have an autoimmune disorder of the thyroid. If you are diagnosed with Hashimoto disease or Grave’s disease, there are medicines you can take to manage your condition.
Learn more about laboratory tests, reference ranges, and understanding results.
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