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Transferability and Between Laboratory Imprecision of an LC-MS/MS-Based Reference Measurement Procedure for
L Renee Ruhaak1, Zsuzsanna Kuklenyik2, Julia Dittrich3
1Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, the Netherlands.
Clinical Chemistry
|April 17, 2026
Summary
This study demonstrates the successful transfer of a multiplex apolipoprotein LC-MS/MS reference measurement procedure between three labs. The method achieved high accuracy and precision for seven apolipoproteins, ensuring reliable standardization.
Area of Science:
- Clinical Chemistry
- Mass Spectrometry
- Analytical Chemistry
Background:
- Standardization of apolipoprotein measurements across laboratories is crucial for accurate clinical diagnostics.
- A multiplexed liquid chromatography-tandem mass spectrometry (LC-MS/MS) reference measurement procedure (RMP) was developed for seven serum apolipoproteins.
- Evaluating the RMP's transferability and inter-laboratory precision is essential for its widespread adoption.
Purpose of the Study:
- To assess the transferability of a multiplex apolipoprotein LC-MS/MS RMP between three calibration laboratories.
- To determine the between-laboratory imprecision of the RMP for specific apolipoproteins.
- To validate the RMP's performance against predefined analytical criteria.
Main Methods:
- Six ring trial surveys were conducted, sharing the study protocol, calibrators, internal standards, quality controls (QCs), and clinical samples (CSs).
- Intra-laboratory imprecision and inter-peptide comparisons assessed within-lab performance.
- Inter-laboratory imprecision was evaluated to determine equivalence between calibration labs.
Main Results:
- Intra-laboratory imprecision met predefined analytical performance criteria (repeatability <50% of maximum allowable uncertainty).
- Median inter-laboratory variation (CVbl) ranged from 3.33% to 7.38% for most apolipoproteins, with apo(a) showing concentration-dependent variation.
- Average imprecision in QC samples decreased over time, indicating improved analytical performance and harmonization.
Conclusions:
- The multiplex apolipoprotein LC-MS/MS RMP is transferable between laboratories.
- Predefined performance specifications were successfully met for all seven measured apolipoproteins.
- Continued round-robin studies will support accurate value assignment for apolipoprotein certification of commercial reagents.
