About Thyroglobulin Antibodies
Thyroglobulin antibodies (TgAb) are immune proteins that mistakenly attack thyroglobulin, the precursor protein the thyroid uses to make its hormones. Elevated TgAb are one of the key diagnostic markers of Hashimoto's thyroiditis — the most common cause of hypothyroidism in the developed world — and can be positive for years before thyroid function visibly declines. TgAb are also used in thyroid cancer surveillance: after thyroid removal, rising TgAb can indicate cancer recurrence even when thyroglobulin itself remains undetectable.