Thyroid Perioxdase (TPO), an enzyme generally found in the thyroid gland, plays an

essential role in the production of thyroid hormones. A TPO test detects antibodies against

TPO in the blood. Antithyroid microsomal antibody is a test to measure antithyroid

microsomal antibodies in the blood. Microsomes are found inside thyroid cells. The body

produces antibodies to microsomes when there has been damage to thyroid cells. It is

associated with autoimmune conditions can also be associated with thyroid disorders, such as

Hashimoto's thyroiditis and Grave's disease.