title: [Free thyroxine immunoassay: analytical review].
abstract: Thyroid hormones assays (T4 and T3) are limited to the free forms with hormonal activity, the only ones useful for the assessment of thyroid function. Free thyroxine assays are part of prescribed parameters by the physician once known plasma TSH concentration. A reference method exists, but immunoassays are the most commonly technics used in current practice. After a reminder of the iodothyronine biochemistry and physiology, the authors discuss preanalytical and analytical steps in detail, focusing on the possible pitfalls.
authors.affiliation: Laboratoire de surveillance et épidémiologie nutritionnelles en Tunisie (SURVEN), Institut national de nutrition et de technologie alimentaire, Tunis, Tunisie.
authors.forename: Radhouene
authors.initials: R
authors.lastname: Doggui
authors.affiliation: Acorata, Unité de formation continue, Sajas, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Ingrand
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods / Q000592:standards; D064420:Drug-Related Side Effects and Adverse Reactions / Q000097:blood; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards; D012016:Reference Values; D013959:Thyroid Diseases / Q000097:blood / Q000139:chemically induced; D013960:Thyroid Function Tests / Q000379:methods* / Q000592:standards; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000032:analysis / Q000097:blood* / Q000378:metabolism; D014284:Triiodothyronine / Q000097:blood
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine
keywords: immunoassay; thyreostimulin; thyroid hormones