Autoantibodies Against Thyroid Hormones or lodothyronine

Abstract

The presence of antithyroid hormone autoantibodies in the sera of patients with thyroid and nonthyroid disorders is a well-known condition. When circulating thyroid hormones bind to the patients' immunoglobulins, serum levels of total and free thyroid hormones are often in discordance with clinical features. This problem occurs because the autoantibodies can interfere with radioimmunoassays. To avoid inappropriate treatment of such patients, it is clinically important to consider the presence of autoantibodies in patients with unexpectedly high or low total and free thyroid hormone values. We have reviewed the English and Japanese literature, both case reports and basic works, and summarize the incidence of antithyroid hormone autoantibodies, clinical features, effects on appropriate testing of the hypothalamic-pituitary-thyroid axis, diagnostic methods for confirming their presence of autoantibodies, treatment of patients with these disorders, and possible pathogenetic mechanisms.

Immunoglobulin G Can Cross-React With Glucagon Antisera and Cause a Spuriously High Plasma Immunoreactive Glucagon Level.

“…These observations suggest that the patient had biologically inactive glucagon of nontumorous origin or had some interference factor with the present radioimmunoassay (RIA) system in plasma. Gel filtration studies showed that the glucagon immunoreactivity was mainly eluted in the v-globulin fraction and this is in agreement with the finding that the glucagon level in the supernatant after removing the y -globulin fraction by PEG was Autoantibodies to insulin [8], thyroid hormone [9], PRL [10] and glucagon [11] have been reported.…”

Fatores Interferentes na Interpretação de Dosagens Laboratoriais no Diagnóstico de Hiper e Hipotireoidismo

“…A prevalência dos THAAb na população é de 0 a 1,8% e cerca de 1 a 10% nas doenças autoimunes tireoidianas e não tireoidianas (117,119). A prevalência varia de acordo com o método utilizado e o grupo de pacientes analisados (120,121). Os THAAb se ligam ao T 4 e T 3 marcado e ao T 4 e T 3 da amostra levando a resultados falsamente elevados ou diminuídos de T 4 e T 3 livre e/ou total dependendo do método utilizado (118,122).…”

Interference of anti-T3 autoantibodies in the measurement of total and free T3 in serum

“…Immunoglobulins have also been found to interfere in immunoasays, particularly in patients with thyroid autoimmune disease (3,7). Most often such a condition results in mild to moderate elevation in the levels of the thyroid hormones due to increased binding capacity of plasma proteins (5).…”

“…It is very rare that such autoantibodies are generated against the thyroid hormones themselves (2,3). The presence of these antibodies in serum does not onty complicate the clinical manifestations of the disease but also interferes with the estimation of total and free hormones by immuno assay (3,4,5).…”

“…It is very rare that such autoantibodies are generated against the thyroid hormones themselves (2,3). The presence of these antibodies in serum does not onty complicate the clinical manifestations of the disease but also interferes with the estimation of total and free hormones by immuno assay (3,4,5). Their presence may be indicated when very low (undetectable) values of either or both T3 and T4 are observed in a competitive RINEIA that uses precipitation for the separation of" bound and free ligand (6).…”