Interferences of Circulating Anti-TSH Antibodies in Methods for Thyrotropin Measurement
| Autor: | Paolo Beck-Peccoz, Giovanni Faglia, Cristina Rossi, G. Medri |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
endocrine system
medicine.medical_specialty endocrine system diseases biology Chemistry Autoantibody Analytical chemistry Radioimmunoassay Endogeny Endocrinology Internal medicine Thyrotropin Measurement Monoclonal medicine biology.protein In patient Antibody hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | Thyroid Autoimmunity ISBN: 9781461282587 |
| DOI: | 10.1007/978-1-4613-0945-1_123 |
| Popis: | Thyrotropin (TSH)immunometric assays may lose their peculiar specif icity when heterophilic antibodies 1,2 or anti-TSH antibodies 3,4 a re present in a given sample. In fact, both these kinds of antibodies may interfere in TSH immunometric assays, giving inappropriate hormone values, clearly inconsistent with other laboratory or clinical findings. In particular, circulating heterophilic antibodies, i.e. antibodies cross-reacting with immunoglobulins (Ig) of the animal in which the assay-specific antibody has been raised, cause spuriously high values both in TSH radioimmunoassays (TSH-RIA) and in TSH immunoradiometric assays (TSH-IRMA).In TSH-RIA, the interference is usually due to an anti-rabbit Ig which neutralizes part of the rabbit anti-TSH antibody1, while in TSH-IRMA it is due to an antimouse Ig which bridges both the labeled and solid-phased monoclonal antibo- p dies, thus behaving as a complete TSH molecule2. On the contrary, the interference in TSH-RIA of circulating anti-TSH antibodies, i.e. antibodies induced by bovine TSH (bTSH) or impure pituitary extract injections, or occasionally found (autoantibodies?) in patients with Graves’disease5, is mainly due to the sequestration of the tracer by the endogenous antibodies. Using second antibody (2nd Ab) separation methods or solid-phase techniques, spuriously high TSH-RIA levels are usually found3,4,since the radioactivity either precipitated with 2nd Ab or bound to the solid-phased antibody decreases, giving TSH values higher than the actual ones, when extrapolated from the standard curve. |
| Databáze: | OpenAIRE |
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