TY - JOUR
T1 - Description and validation of an equilibrium dialysis ID-LC-MS/MS candidate reference measurement procedure for free thyroxine in human serum
AU - Jansen, Heleen I.
AU - van der Steen, Rob
AU - Brandt, André
AU - Olthaar, André J.
AU - Vesper, Hubert W.
AU - Shimizu, Eri
AU - Heijboer, Annemieke C.
AU - van Uytfanghe, Katleen
AU - van Herwaarden, Antonius E.
N1 - Funding Information:
Research funding: This research project was funded by the Dutch Foundation of Quality Assessment in Medical Laboratories (SKML) and Landelijke Werkgroep Bindingsanalyse (LWBA). The SKML and LWBA played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.
Publisher Copyright:
© 2023 De Gruyter. All rights reserved.
PY - 2023
Y1 - 2023
N2 - Free thyroxine (FT4) in serum is routinely measured in clinical practice to diagnose and monitor thyroid disease. Due to its concentration in picomolar range and the delicate equilibrium of free and protein-bound T4, accurate measurement is challenging. As a consequence, large inter-method differences in FT4 results exists. Optimal method design and standardization of the FT4 measurement is therefore necessary. The IFCC Working Group for Standardization of Thyroid Function Tests proposed a reference system with a conventional reference measurement procedure (cRMP) for FT4 in serum. In this study, we describe our FT4 candidate cRMP and its validation in clinical samples. This candidate cRMP is based on equilibrium dialysis (ED) combined with determination of T4 with an isotope-dilution liquid chromatography tandem mass-spectrometry (ID-LC-MS/MS) procedure and was developed according to the endorsed conventions. Its accuracy, reliability, and comparability was investigated using human sera. It was shown that the candidate cRMP adhered to the conventions and its accuracy, precision, and robustness were adequate in serum of healthy volunteers. Our candidate cRMP measures FT4 accurately and performs well in serum matrix.
AB - Free thyroxine (FT4) in serum is routinely measured in clinical practice to diagnose and monitor thyroid disease. Due to its concentration in picomolar range and the delicate equilibrium of free and protein-bound T4, accurate measurement is challenging. As a consequence, large inter-method differences in FT4 results exists. Optimal method design and standardization of the FT4 measurement is therefore necessary. The IFCC Working Group for Standardization of Thyroid Function Tests proposed a reference system with a conventional reference measurement procedure (cRMP) for FT4 in serum. In this study, we describe our FT4 candidate cRMP and its validation in clinical samples. This candidate cRMP is based on equilibrium dialysis (ED) combined with determination of T4 with an isotope-dilution liquid chromatography tandem mass-spectrometry (ID-LC-MS/MS) procedure and was developed according to the endorsed conventions. Its accuracy, reliability, and comparability was investigated using human sera. It was shown that the candidate cRMP adhered to the conventions and its accuracy, precision, and robustness were adequate in serum of healthy volunteers. Our candidate cRMP measures FT4 accurately and performs well in serum matrix.
KW - LC-MS/MS
KW - conventional reference measurement procedure
KW - free thyroxine
KW - standardization
UR - http://www.scopus.com/inward/record.url?scp=85151825545&partnerID=8YFLogxK
U2 - 10.1515/cclm-2022-1134
DO - 10.1515/cclm-2022-1134
M3 - Article
C2 - 36994743
SN - 1434-6621
JO - Clinical Chemistry and Laboratory Medicine
JF - Clinical Chemistry and Laboratory Medicine
ER -