Thyroid microsomal antibodies (anti-TPO) Thyreoid. microsomal al. (TPO) in English: Thyroid peroxidase antibody. MAK
This test is performed to detect autoimmune thyroid disease; an abnormality of the thyroid gland caused by the immune system malfunctioning.
The test measures the amount of antibodies to thyroperoxidase (TPO), a protein found only in the thyroid gland. Antibodies to TPO are so-called autoantibodies that target the thyroid gland.
Normally, the immune system makes antibodies to make unwanted invaders or pathogens harmless. Sometimes something goes wrong causing antibodies to be made against healthy cells, tissue or organs in the body. It leads to so-called autoimmune disease in which unintentional damage and inflammation occurs to body tissues and organs, such as the thyroid in this case.
Antibodies to TPO often occur in people in whom the thyroid gland produces too little thyroid hormone (T4). However, the antibodies can also occur in people in whom the thyroid gland actually produces too much thyroid hormone. Even in healthy individuals, small amounts of antibodies to TPO can occur.
Most healthy people have no thyroid antibodies in their blood. However, (older) women have a greater chance (especially as age advances) of producing thyroid autoantibodies. Some of this group will later develop thyroid disorders.
Mildly to moderately elevated amounts of thyroid antibodies are found in various thyroid and autoimmune disorders such as diabetes and rheumatoid arthritis.
The detection of antibodies to thyroid peroxidase is not necessarily evidence of autoimmune thyroid disease. Slightly elevated values occur in 5% of all healthy people.
Highly elevated values indicate thyroid disease due to autoantibodies, such as Hashimoto's disease (poorly functioning thyroid) or Graves' disease (overactivity of the thyroid).
Microsomal antibodies occur in M.Basedow, (Graves' disease)
accompanying thyroiditis, after surgery or radioiodine therapy. High concentrations are an indication of immune thyroiditis and a good parameter for therapy control.
To get an idea of the course of the disease, the test is repeated with some regularity. An increasing amount of thyroid autoantibodies indicates an increase in autoimmune activity. During pregnancy, these antibodies can also lead to thyroid problems in the unborn child.
Unit of reporting 1 kU/L= 1 IU/mlneuron cell antigens/neural
antigens thyroid (-microsomes) (TPO), thyreoid. microsm. al.