About Thyroid Peroxidase Antibodies
Thyroid peroxidase antibodies (TPO Ab) target the enzyme that catalyses thyroid hormone synthesis, and their presence is the strongest blood marker for autoimmune thyroid disease. Elevated TPO Ab are found in over 90% of people with Hashimoto's thyroiditis and in most people with Graves' disease (hyperthyroidism). Positive TPO Ab can precede thyroid dysfunction by a decade or more, identifying individuals who need monitoring and who may benefit from gluten elimination, selenium optimisation, or stress management to slow immune attack.