caa a22 4500 378879294 CHVBK 20180305123428.0 cr unu---uuuuu 161128e20030721xx s 000 0 eng 10.1515/CCLM.2003.143 doi (NATIONALLICENCE)gruyter-10.1515/CCLM.2003.143 Clinical Evaluation of Nine Free Thyroxine Assays: Persistent Problems in Particular Populations [Elektronische Daten] [Michèle d'Herbomez, Gérard Forzy, Françoise Gasser, Catherine Massart, Andrée Beaudonnet, Rèmy Sapin] Over the past decade, numerous papers have addressed the various methodological problems encountered with free thyroxine (FT4) assays. We evaluated the clinical performance of nine FT4 assays in five centres, using a panel of 310 sera: 156 from euthyroid controls; 27 from hyperthyroid patients; 34 from untreated hypothyroidism; 22 from patients with renal failure; 30 from women in the last trimester of pregnancy; 23 from patients on thyroid substitutive therapy; and 18 from patients treated with amiodarone. Only three methods showed a Gaussian distribution of FT4 concentrations. Reference ranges were calculated using the 2.5th and 97.5th percentiles. A significant difference was observed between FT4 values in men and women. The areas under the receiver operating characteristic (ROC) curves ranged from 0.996 to 1 for hyperthyroidism and from 0.973 to 1 for hypothyroidism. In sera from patients with renal failure and from pregnant women, method-dependent biases were observed and confirmed with dilution experiments. In conclusion, current FT4 assays show good performance regarding the diagnosis of overt dysthyroidism. Nevertheless, FT4 measurements are still vulnerable to method-dependent artefacts in particular populations such as patients with renal failure and pregnant women. Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Medical equipment & techniques nationallicence Medical diagnosis nationallicence Diseases & disorders nationallicence d'Herbomez Michèle aut Forzy Gérard aut Gasser Françoise aut Massart Catherine aut Beaudonnet Andrée aut Sapin Rèmy aut Clinical Chemistry and Laboratory Medicine Walter de Gruyter 41/7(2003-07-21), 942-947 1434-6621 41:7<942 2003 41 cclm https://doi.org/10.1515/CCLM.2003.143 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/CCLM.2003.143 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- d'Herbomez Michèle aut NATIONALLICENCE 700 1- Forzy Gérard aut NATIONALLICENCE 700 1- Gasser Françoise aut NATIONALLICENCE 700 1- Massart Catherine aut NATIONALLICENCE 700 1- Beaudonnet Andrée aut NATIONALLICENCE 700 1- Sapin Rèmy aut NATIONALLICENCE 773 0- Clinical Chemistry and Laboratory Medicine Walter de Gruyter 41/7(2003-07-21), 942-947 1434-6621 41:7<942 2003 41 cclm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter