Thyroid Peroxidase (TPO) is an integral apical membrane glycoprotein of thyroid follicular cells, which is responsible for the of tyrosine residues in thyroglobulin, leading to thyroid hormone generation (Ruf and Carayon, 2006). In membrane TPO is found as a homodimer with subunits of approximately 100 kDa molecular weight (Baker et al. 1994). The anti-thyroid peroxidase autoantibodies are the most frequently represented autoantibodies in the sera of patients suffering from autoimmune thyroid disease; they are present in 90% of Hashimoto’s thyroiditis and 75% of Graves’ disease patients (Mariotti et al. 1990). Thus immunoassays for quantification of anti-TPO autoantibodies are widely used in clinical practice. For many years human native TPO, purified from thyroid glands, was used as a key component – an antigen – in such assays. Studies in early 90s revealed that soluble extracellular domain of recombinant human thyroid peroxidase (rTPO) produced in insect cells has immunochemical properties similar to native human thyroid peroxidase (Haubruck et al. 1993). But technical limitations in the production of bulk amounts of rTPO imposed some restrictions on the wide rTPO utilization in assays.
Recombinant human TPO offered by Advanced ImmunoChemical has immunochemical properties similar to the native antigen, purified from human thyroid glands and can be utilized as an antigen in the assays for the detection of human TPO-specific autoantibodies in the blood of the patients with autoimmune thyroid diseases.