Thyroid Peroxidase TPO Antibody
Also known as
Thyroid Autoantibodies, Antithyroid Antibodies, Antimicrosomal Antibody, Thyroid Microsomal Antibody, Thyroid Peroxidase Antibody, Thyroperoxidase Antibody, TPO, Anti-TPO, TBII, Antithyroglobulin Antibody, TgAb, TSH Receptor Antibody, TRAb, Thyrotropin Receptor Antibodies, Thyroid Stimulating Immunoglobulin, TSI
This test is ordered by the doctor to aid in the diagnosis and monitoring of autoimmune thyroid diseases. The test helps in distinguishing between other forms of thyroid disease and these disorders. It also aids in planning out treatment.
This test is ordered by the doctor when the patient has an enlarged goitre or when his or her thyroid test results such as total or free T3, free T4 and TSH have abnormal levels indicating thyroid dysfunction. In addition, it may be ordered alongside the thyroglobulin test when the doctor uses it as a monitoring tool and at planned intervals when the doctor is monitoring the patient for autoimmune thyroid disorders.
This is a blood test. The technician draws blood from a vein in the arm using a syringe.
There is no preparation needed for the test.
This test detects the presence of and assesses the number of thyroid antibodies in the blood. Thyroid antibodies are those which develop when the immune system mistakenly identifies the thyroid gland or thyroid proteins as a threat and attacks these components. This leads to chronic inflammation of the thyroid, damage in the tissues and the disruption of thyroid function.
The thyroid gland is a small butterfly-shaped gland that is found against the windpipe in the throat. The gland makes two primary hormones - T4 and T3 - both of which are crucial in the regulation and management of how the body uses energy - also known as the process of metabolism. The body uses a feedback system to carry out this process. This consists of the thyroid gland being stimulated by the thyroid-stimulating hormone when T4 and T3 are needed by the body. The feedback system aids in the maintenance of a stable amount of thyroid hormones in the blood. Thyroid antibodies interfere with this process, leading to chronic conditions and autoimmune disorders, which are linked to hypothyroidism and hyperthyroidism like Graves disease.
Thyroid antibodies test consist of the following:
Thyroid peroxidase antibody is also known as TPO
Thyroglobulin antibody, also known as TGA
Thyroid stimulating hormone receptor antibodies TSHRAb, including thyroid stimulating
immunoglobulin
TSI and thyroid binding inhibitory immunoglobulin TBII.
This test is used to diagnose autoimmune thyroid disease and delineate it from other kinds of thyroid disorders. In order to establish a concrete diagnosis or monitor an autoimmune disorder, single or multiple tests may be performed depending on the situation at hand. For example, the thyroid peroxidase antibody is the most commonly used tests for autoimmune thyroid disease. This can be detected for Graves disease or Hashimoto thyroiditis. On the other hand, TGAb is an antibody that targets
thyroglobulin,
which is the storage form of thyroid hormones. The thyroid stimulating hormone receptor antibodies include two types of autoantibodies that attach to proteins found in the thyroid, which are normally bound by TSH. The thyroid stimulating immunoglobulin binds to receptors, increasing the production of thyroid hormones - a condition called hyperthyroidism, and the thyroid binding inhibitory immunoglobulin hormone prevents the TSH from binding to receptors, disrupting the production of thyroid hormones and decreasing it - this condition is called hyperthyroidism. While this hormone is not routinely checked, TSI is used to diagnose Graves disease.
Tests are also useful in investigating enlarged goitre and other sighs related to low or high thyroid hormone levels. This test acts as a follow up to total or free T3, free T4 and other TSH, which indicates thyroid dysfunction. The antibody tests are also used to gauge if someone with an autoimmune condition is at risk of developing thyroid dysfunction – this can occur with conditions like pernicious anaemia. Thyroglobulin tests are used to monitor treatment for thyroid cancer.
The test is ordered as a follow-up or in response to symptoms of low or high thyroid levels. Signs of high thyroid levels include:
Sweating
Rapid heart rate
Anxiety
Tremors
Fatigue
Difficulty sleeping
Sudden weight loss
Protruding eyes
Signs of low thyroid levels include
Weight gain
Fatigue
Dry skin
Hair loss
Intolerance to cold
Constipation
Negative test results indicate that no thyroid antibodies were found. This implies that thyroid symptoms are not linked to autoimmune disease. Positive results imply that antibodies to TPO and/or Tg were found. The results indicate Hashimoto disease. People with Hashimoto disease have high levels of both or one of the antibodies. Positive test results also imply that antibodies to TPO and/or TSH receptor have been detected; this implies Grave’s disease. The higher the number of antibodies found in the result, the more likely it is that the patient has an autoimmune disorder related to the thyroid.
Related Tests
Thyroid-stimulating Hormone (TSH), T4, Free, T3 (Free and Total), Thyroid Panel, Thyroglobulin
