Exploring commutable materials for serum folate measurement: challenges in cross-method harmonization
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Xiaerbanu Nizhamuding
and
Chuanbao Zhang
Abstract
Objectives
Commutability is a critical attribute for reference materials (RMs) employed in standardization and calibration activities, it ensures the accuracy and equivalence of analytical results across heterogeneous measurement systems and laboratories. In the context of folate quantification, commutability holds particular significance, as it validates that RMs exhibit analytical behavior equivalent to native clinical specimens when subjected to diverse folate detection platforms. This study aims to identify and characterize commutable candidate RMs for serum folate assays, with the ultimate goal of enhancing the harmonization and metrological traceability of folate measurements in clinical diagnostics.
Methods
Thirty study materials and pooled clinical serum samples were measured by two isotope-dilution liquid chromatography tandem mass spectrometry methods and three immunoassays in four different laboratories. Six external quality assessment materials for endocrine, 6 trueness verification materials for vitamins, 13 processed materials and 5 candidate RMs (cRM-1,2,3,4,5) were assessed. Deming regression analysis and the difference-in-bias approach were employed to evaluate commutability.
Results
cRM-3 demonstrated commutability (C or +) across all assays, being the most ideal candidate reference material in this study. Seven materials (cRM-1, cRM-2, cRM-3, TV202111, TV202012, CS-L, and RS 2W-1) were commutable for two LC-MS/MS methods regardless of the statistical method.
Conclusions
The complexity of folate species in serum, differences in detection principles between immunoassays and isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method (immunoassays using folate-binding protein with variable affinities and LC-MS/MS quantifying specific vitamers), and variations in calibration substrates among immunoassays collectively challenge the harmonization of folate measurement and commutability assessment.
Funding source: National Key Research and Development progrem of China
Award Identifier / Grant number: No. 2022YFF0710305
Funding source: National High Level Hospital Clinical Research Funding
Award Identifier / Grant number: BJ-2023-106
Acknowledgment
The sera collected from Beijing Hospital and used in this study were also employed in our previous work (Jin et al. [13]). The overlap in the data serves solely to illustrate the performance of the method. The study materials have not been published elsewhere and are exclusively used in this research. We’re grateful for the support and technical guidance of engineers of Abbott, Roche, Beckman.
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Research ethics: The local Institutional Review Board deemed the study exempt from review.
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Informed consent: This study was approved for the exemption from informed consent.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The authors state no conflict of interest.
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Research funding: National Key Research and Development Program of China (No. 2022YFF0710305); National High Level Hospital Clinical Research Funding (BJ-2023-106).
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Data availability: The raw data can be obtained on request from the corresponding author.
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Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/cclm-2024-1403).
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