2010 – anti-Tg magnum

The anti-Tg magnum is a quantitative immunoassay for the determination of antibodies against thyroglobulin (Tg) in human serum. The anti-Tg magnum is intended as an aid in the diagnosis of autoimmune thyroid diseases in conjunction with other clinical and laboratory findings.

Thyroglobulin (Tg), an iodine containing glycoprotein and precursor of the thyroid hormones thyroxine (T4) and triiodothyronine (T3), makes up a major part of thyroid colloid. The biosynthesis of Tg is regulated by thyrotropin, the only thyroid tissue that can produce, store and secrete Tg; Tg is thus organ- and tissue specific. This specificity is the main indication of the Tg determination in monitoring differentiated thyroid carcinoma, essential in the early detection and exclusion of metastases or tumour relapses.

The presence of autoantibodies to thyroid antigens is an indication of autoimmune thyroiditis. These autoantibodies target the thyroid glands and its hormone products T3, T4 and TSH leading to hormonal dysfunction. Detection of such autoantibodies in an indication of chronic autoimmune thyroiditis, hence a marker for the differential diagnosis of hypothyroidism and the subclinical or latent type. Detection of anti-Tg is also essential in the diagnosis of Grave’s disease, especially when the TSH Receptor Antibody value is negative, but the disease is clinically suspected.

Radioimmunoassays are widely used for the determination of specific antibodies. For this purpose tracer molecules composed of antigens conjugated to radioactive components detect specific antibodies in the patient´s sample. Protein A coated to magnetic particles binds antibodies from the sample and allows for the simple separation of generated immune complexes from the reaction mixture by use of a magnetic device. The radioactivity of the precipitate is measured and proportional to the antibody activity in the sample.

The immunoassay is designed for manual professional in vitro diagnostic use.