Standard Document
First Edition
Clinical Chemistry and Toxicology

CLSI C45

Measurement of Free Thyroid Hormones

CLSI C45 provides comprehensive guidance on the measurement of free (nonprotein-bound) thyroid hormones (FTH), addressing key factors such as test design, specimen selection, and confounding variables. This guideline emphasizes the analytical and clinical validation of FTH measurement procedures, ensuring accuracy, metrological traceability, and robustness against influencing factors. It also includes recommendations for implementing a reference measurement system to enhance the development and validation of in vitro diagnostic medical devices.

October 20, 2004
Linda Thienpont, PhD

{{FormatPrice(currentPrice)}}

Free

{{FormatPrice(nonMemberPrice)}} List Price
This is your member pricing.
Notify Me About New Editions
Abstract

Clinical and Laboratory Standards Institute document C45-A—Measurement of Free Thyroid Hormones; Approved Guideline is a guideline for free (nonprotein- bound) thyroid hormone (FTH) testing. The primary audience for this publication is personnel responsible for the development, manufacture, approval, and/or use of FTH measurement procedures. The guideline briefly discusses FTH measurement procedures with respect to design, factors confounding measurements, and specimen choice and collection, and addresses existing problems in definitions and specific nomenclature. However, it mainly emphasizes analytical and clinical validation of FTH measurement procedures. Assessment of analytical validity of an FTH measurement procedure not only implies demonstration of sufficient intrinsic quality or robustness against challenging factors, but also of metrological traceability to the Système International d'Unités (SI). In this respect, the guideline provides recommendations on the implementation of a reference measurement system in the development/validation process of in vitro diagnostic medical devices.

Scope
This guideline, C45-A—Measurement of Free Thyroid Hormones; Approved Guideline, gives an overview of the pathophysiology of blood free thyroid hormones (FTH) and of the principles and limitations of current routine measurement procedures. Recommendations are included for specimen collection, stability, and storage. The main focus of the document is on the analytical and clinical validation of FTH measurement procedures and on their standardization by implementation of a reference measurement system. Specific recommendations for validating both analytical and clinical performance are provided. Direct equilibrium dialysis (ED) and direct ultrafiltration (UF) are proposed as candidate reference measurement procedures, and recommendations are provided for appropriate use and calibration of these measurement procedures. Lastly, the document provides a summary of the objectives and status of the European project to develop higher order reference measurement procedures for free thyroid hormones.
Product Details
C45AE
1-56238-548-8
62
Additional Details

This document is available in electronic format only.

This archived document is no longer being reviewed through the CLSI Consensus Document Development Process. However, this document is technically valid and because of its value to the laboratory community, it is being retained in CLSI’s library.

A CLSI-IFCC joint project.

Authors
Linda Thienpont, Ph.D.
David M. Bunk, Ph.D.
Nicos D. Christofides, Ph.D.
James D. Faix, M.D.
Charles A. Lewis, Jr., Ph.D.
Jeffry K. Russell, Ph.D.
Carole Ann Spencer, Ph.D.
Bernard W. Steele, M.D.
Professor Dr. Joseph H. H. Thijssen
H. Alec Ross, Ph.D.
Abstract

Clinical and Laboratory Standards Institute document C45-A—Measurement of Free Thyroid Hormones; Approved Guideline is a guideline for free (nonprotein- bound) thyroid hormone (FTH) testing. The primary audience for this publication is personnel responsible for the development, manufacture, approval, and/or use of FTH measurement procedures. The guideline briefly discusses FTH measurement procedures with respect to design, factors confounding measurements, and specimen choice and collection, and addresses existing problems in definitions and specific nomenclature. However, it mainly emphasizes analytical and clinical validation of FTH measurement procedures. Assessment of analytical validity of an FTH measurement procedure not only implies demonstration of sufficient intrinsic quality or robustness against challenging factors, but also of metrological traceability to the Système International d'Unités (SI). In this respect, the guideline provides recommendations on the implementation of a reference measurement system in the development/validation process of in vitro diagnostic medical devices.

Scope
This guideline, C45-A—Measurement of Free Thyroid Hormones; Approved Guideline, gives an overview of the pathophysiology of blood free thyroid hormones (FTH) and of the principles and limitations of current routine measurement procedures. Recommendations are included for specimen collection, stability, and storage. The main focus of the document is on the analytical and clinical validation of FTH measurement procedures and on their standardization by implementation of a reference measurement system. Specific recommendations for validating both analytical and clinical performance are provided. Direct equilibrium dialysis (ED) and direct ultrafiltration (UF) are proposed as candidate reference measurement procedures, and recommendations are provided for appropriate use and calibration of these measurement procedures. Lastly, the document provides a summary of the objectives and status of the European project to develop higher order reference measurement procedures for free thyroid hormones.
Additional Details

This document is available in electronic format only.

This archived document is no longer being reviewed through the CLSI Consensus Document Development Process. However, this document is technically valid and because of its value to the laboratory community, it is being retained in CLSI’s library.

A CLSI-IFCC joint project.

Authors
Linda Thienpont, Ph.D.
David M. Bunk, Ph.D.
Nicos D. Christofides, Ph.D.
James D. Faix, M.D.
Charles A. Lewis, Jr., Ph.D.
Jeffry K. Russell, Ph.D.
Carole Ann Spencer, Ph.D.
Bernard W. Steele, M.D.
Professor Dr. Joseph H. H. Thijssen
H. Alec Ross, Ph.D.