Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods
Clinicians often encounter thyroid function tests (TFT) comprising serum/plasma free thyroxine (FT4) and thyroid stimulating hormone (TSH) measured using different assay platforms during the course of follow-up evaluations which complicates reliable comparison and interpretation of TFT changes. Alth...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-01-01
|
| Series: | Biology |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-7737/10/1/45 |
| _version_ | 1797413423137423360 |
|---|---|
| author | Fanwen Meng Jacqueline Jonklaas Melvin Khee-Shing Leow |
| author_facet | Fanwen Meng Jacqueline Jonklaas Melvin Khee-Shing Leow |
| author_sort | Fanwen Meng |
| collection | DOAJ |
| description | Clinicians often encounter thyroid function tests (TFT) comprising serum/plasma free thyroxine (FT4) and thyroid stimulating hormone (TSH) measured using different assay platforms during the course of follow-up evaluations which complicates reliable comparison and interpretation of TFT changes. Although interconversion between concentration units is straightforward, the validity of interconversion of FT4/TSH values from one assay platform to another with different reference intervals remains questionable. This study aims to establish an accurate and reliable methodology of interconverting FT4 by any laboratory to an equivalent FT4 value scaled to a reference range of interest via linear transformation methods. As a proof-of-concept, FT4 was simultaneously assayed by direct analog immunoassay, tandem mass spectrometry and equilibrium dialysis. Both linear and piecewise linear transformations proved relatively accurate for FT4 inter-scale conversion. Linear transformation performs better when FT4 are converted from a more accurate to a less accurate assay platform. The converse is true, whereby piecewise linear transformation is superior to linear transformation when converting values from a less accurate method to a more robust assay platform. Such transformations can potentially apply to other biochemical analytes scale conversions, including TSH. This aids interpretation of TFT trends while monitoring the treatment of patients with thyroid disorders. |
| first_indexed | 2024-03-09T05:18:39Z |
| format | Article |
| id | doaj.art-ea25ebfb819946dd93b077cee3d03f22 |
| institution | Directory Open Access Journal |
| issn | 2079-7737 |
| language | English |
| last_indexed | 2024-03-09T05:18:39Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biology |
| spelling | doaj.art-ea25ebfb819946dd93b077cee3d03f222023-12-03T12:43:48ZengMDPI AGBiology2079-77372021-01-011014510.3390/biology10010045Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation MethodsFanwen Meng0Jacqueline Jonklaas1Melvin Khee-Shing Leow2National Healthcare Group, Department of Health Services and Outcomes Research, 3 Fusionopolis Link, Nexus@One-North, Singapore 138543, SingaporeDivision of Endocrinology, Department of Medicine, Georgetown University, 4000 Reservoir Road NW, Washington, DC 20057, USALee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232, SingaporeClinicians often encounter thyroid function tests (TFT) comprising serum/plasma free thyroxine (FT4) and thyroid stimulating hormone (TSH) measured using different assay platforms during the course of follow-up evaluations which complicates reliable comparison and interpretation of TFT changes. Although interconversion between concentration units is straightforward, the validity of interconversion of FT4/TSH values from one assay platform to another with different reference intervals remains questionable. This study aims to establish an accurate and reliable methodology of interconverting FT4 by any laboratory to an equivalent FT4 value scaled to a reference range of interest via linear transformation methods. As a proof-of-concept, FT4 was simultaneously assayed by direct analog immunoassay, tandem mass spectrometry and equilibrium dialysis. Both linear and piecewise linear transformations proved relatively accurate for FT4 inter-scale conversion. Linear transformation performs better when FT4 are converted from a more accurate to a less accurate assay platform. The converse is true, whereby piecewise linear transformation is superior to linear transformation when converting values from a less accurate method to a more robust assay platform. Such transformations can potentially apply to other biochemical analytes scale conversions, including TSH. This aids interpretation of TFT trends while monitoring the treatment of patients with thyroid disorders.https://www.mdpi.com/2079-7737/10/1/45reference intervalsassaysscale transformationequilibrium dialysisthyroid hormones |
| spellingShingle | Fanwen Meng Jacqueline Jonklaas Melvin Khee-Shing Leow Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods Biology reference intervals assays scale transformation equilibrium dialysis thyroid hormones |
| title | Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods |
| title_full | Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods |
| title_fullStr | Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods |
| title_full_unstemmed | Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods |
| title_short | Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods |
| title_sort | interconversion of plasma free thyroxine values from assay platforms with different reference intervals using linear transformation methods |
| topic | reference intervals assays scale transformation equilibrium dialysis thyroid hormones |
| url | https://www.mdpi.com/2079-7737/10/1/45 |
| work_keys_str_mv | AT fanwenmeng interconversionofplasmafreethyroxinevaluesfromassayplatformswithdifferentreferenceintervalsusinglineartransformationmethods AT jacquelinejonklaas interconversionofplasmafreethyroxinevaluesfromassayplatformswithdifferentreferenceintervalsusinglineartransformationmethods AT melvinkheeshingleow interconversionofplasmafreethyroxinevaluesfromassayplatformswithdifferentreferenceintervalsusinglineartransformationmethods |