Thyreoglobulin (Tg) and thyroid peroxidase (TPO) are in addition to the TSH receptor (TRAK) the major thyroid antigens. Antibodies against Tg and TPO are diagnostic markers of chronic autoimmune thyroiditis and the differential diagnosis of hypothyroidism including its subclinical and latent forms.

The detection of autoantibodies against Tg and TPO serves the exclusion of patients with thyroid diseases, as antibodies against both autoantigens or at least one autoantigen are detected in more than 98% of the patients with autoimmune thyroiditis. Antibodies against Tg occur in 30% of the patients with Graves’ disease (Basedow’s disease) and in 85% of the patients with Hashimoto’s thyreoiditis.

Anti-TPO autoantibodies occur in 71-97% of the patients with Basedow’s disease and in 91-99% of the patients with Hashimoto’s thyreoiditis. Therefore, autoimmune thyreoiditis can be virtually excluded, if neither of both autoantibodies can be detected.

Anti-TPO autoantibodies recognize conformational epitopes only occurring in recombinant TPO expressed in an eukaryotic system, the AESKULISA® a-TPO tests are coated with human recombinant TPO.