Anti-microsomal antibody test measures antibodies present in the blood. The thyroid cells have microsomes inside them. When the thyroid cells are damaged, the body produces antibodies to these microsomes. Also, an enzyme is generally found in the thyroid gland, which is thyroid peroxidase (TPO). This enzyme plays a special role in the production of thyroid hormones. It is also affected by antibodies when the thyroid gland is damaged. It is why the anti-microsomal antibody test is also called the thyroid peroxidase test.
The presence of the antithyroid microsomal antibodies suggests that it is associated with the thyroid glands’ autoimmune conditions. Some of these thyroid diseases include Hashimoto’s thyroiditis and Grave’s disease, wherein the immune system breaks down and produces antibodies against the thyroid gland.