Normalizing Intermethod Free Triiodothyronine Patient Results: Need for Commutable Materials
-
Abstract
The aim of this work was to check the suitability of control materials to normalize intermethod results for the measurement of free triiodothyronine in patient sera. In the main experiment, 108 patient sera and 11 commercially available control materials were assayed by a pair of methods. In a confirmatory experiment, two of the control materials and 142 patient sera were assayed with an alternative pair of methods. In the main experiment, the intermethod variability of 6/11 control materials differed significantly from that of patient sera (i. e. control materials were non-commutable). Recalculation of patient results using control materials as calibrators lowered the intermethod difference only if commutable materials were used. The confirmatory experiment demonstrated that the pattern of commutability changed if a different pair of methods was used. We conclude that in the case of free triiodothyronine the commutability of control materials should be tested if they are to be used to normalize patient results obtained by different methods.
Copyright © 1999 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- Kinetic Study of Apo B100 Containing Lipoprotein Metabolism Using Amino Acids Labeled with Stable Isotopes: Methodological Aspects
- Activated Immune System in Patients with Huntington's Disease
- Elevated Group 11 Phospholipase A2 Mass Concentration in Serum and Colonic Mucosa in Crohn's Disease
- Determination of pH in Human Erythrocytes. Sources of Systematic Error
- Rapid Molecular Diagnosis of Erythropoietic Protoporphyria among Swiss Patients
- Biochemical Evaluation of Oxidative Stress in Propylthiouracil Treated Hyperthyroid Patients. Effects of Vitamin C Supplementation
- Effect of Aminoguanidine on Erythrocyte Lipid Peroxiclation and Activities of Antioxidant Enzymes in Experimental Diabetes
- Normalizing Intermethod Free Triiodothyronine Patient Results: Need for Commutable Materials
- Evaluation of a Predictive Kinetic Procedure for the Enzymatic Measurement of Creatinine in Serum
- Pre-Evaluation and System Optimization of the Elecsys® Thyroid Electrochemiluminescence Immunoassays
- Validation of an Automated Enzyme Immunoassay for Interleukin-6 for Routine Clinical Use
- First Experience with the REMEDi HS Urine Benzodiazepine Assay
- Rapid Variations of the Free Prostate-Specific Antigen Fraction in Serum
- Are the Preanalytical Factors Underestimated in Clinical Studies?
- Book Review
Articles in the same Issue
- Kinetic Study of Apo B100 Containing Lipoprotein Metabolism Using Amino Acids Labeled with Stable Isotopes: Methodological Aspects
- Activated Immune System in Patients with Huntington's Disease
- Elevated Group 11 Phospholipase A2 Mass Concentration in Serum and Colonic Mucosa in Crohn's Disease
- Determination of pH in Human Erythrocytes. Sources of Systematic Error
- Rapid Molecular Diagnosis of Erythropoietic Protoporphyria among Swiss Patients
- Biochemical Evaluation of Oxidative Stress in Propylthiouracil Treated Hyperthyroid Patients. Effects of Vitamin C Supplementation
- Effect of Aminoguanidine on Erythrocyte Lipid Peroxiclation and Activities of Antioxidant Enzymes in Experimental Diabetes
- Normalizing Intermethod Free Triiodothyronine Patient Results: Need for Commutable Materials
- Evaluation of a Predictive Kinetic Procedure for the Enzymatic Measurement of Creatinine in Serum
- Pre-Evaluation and System Optimization of the Elecsys® Thyroid Electrochemiluminescence Immunoassays
- Validation of an Automated Enzyme Immunoassay for Interleukin-6 for Routine Clinical Use
- First Experience with the REMEDi HS Urine Benzodiazepine Assay
- Rapid Variations of the Free Prostate-Specific Antigen Fraction in Serum
- Are the Preanalytical Factors Underestimated in Clinical Studies?
- Book Review
