Thyroid Peroxidase Antibody
Also written as: TPOAb — Thyroid Peroxidase Antibody
An autoantibody against thyroid peroxidase enzyme, elevated in autoimmune thyroid diseases.
Full Definition
Thyroid peroxidase antibody (TPOAb) is an autoantibody directed against thyroid peroxidase, an enzyme essential for thyroid hormone synthesis. TPOAb is the most commonly measured thyroid antibody and is significantly elevated in autoimmune thyroid conditions, particularly Hashimoto's thyroiditis and Graves' disease. Positive TPOAb indicates increased risk for developing hypothyroidism and is associated with thyroid dysfunction during pregnancy. TPOAb levels may fluctuate over time but typically remain elevated once positive.
Usage
Usage note: TPOAb is preferred over the older term 'thyroid microsomal antibody'.
In Context
- "Elevated thyroid peroxidase antibody levels confirmed autoimmune thyroiditis." — Endocrinology consultation
- "TPOAb testing is recommended for pregnant women with subclinical hypothyroidism." — Obstetric endocrinology guideline