TgAb is an autoantibody directed against the thyroglobulin (Tg) protein (the primary constituent of thyroid colloid). While TgAb may be used to assist clinicians in the diagnosis of autoimmune thyroid disease, it is vitally important to determine the presence of TgAb when measuring Tg as a tumor marker for thyroid carcinoma. The presence of detectable levels of TgAb indicates that the amount of Tg measured is inaccurate, as circulating TgAb binds with circulating Tg, causing a varying degree of analytical interference.
The most common analytical methods for TgAb are immunoassays that employ enzyme-linked immunosorbent assay (ELISA) and chemiluminescent immunoassay (CIA) principles.
