Measurement of 1,25-dihydroxyvitamin D in serum by LC-MS/MS compared to immunoassay reveals inconsistent agreement in paediatric samples

Tang, Jonathan C. Y. ORCID: https://orcid.org/0000-0001-6305-6333, Dunn, Rachel, Dutton, John J., Farag, Amrou, Piec, Isabelle ORCID: https://orcid.org/0000-0002-0648-1330, Chipchase, Allison, Greeves, Julie, Fraser, William D. and Webb, Emma A. (2024) Measurement of 1,25-dihydroxyvitamin D in serum by LC-MS/MS compared to immunoassay reveals inconsistent agreement in paediatric samples. Clinical Chemistry and Laboratory Medicine. ISSN 1434-6621

Microsoft Word (OpenXML) (CCLM.2024.1032.R1 Tang CCLM 1,25D paper final) - Accepted Version Available under License Creative Commons Attribution. Download (1MB)

Abstract

Objectives: Automated immunoassays for 1,25-dihydroxyvitamin D (1,25(OH)2D) have increased the use of serum measurements in clinical and research settings, but disagreement with LC-MS/MS methods remains an issue. Methods: In this study, we examined this problem using samples obtained from healthy young adults, n=80, mean age 21.7(18-32)yrs, and a large cohort of paediatric samples, n=422, mean age 7.3(0-17)yrs. We compared serum concentrations of 1,25(OH)2D3/D2 produced by the DiaSorin LIAISON® XL immunoassay against an LC-MS/MS method with immunoaffinity enrichment and DAPTAD derivation. Results: Both assays showed intra/inter-assay imprecision of ≤9.4% across their respective assay range. DEQAS between April 2020 to Jan 2024 (n=80) showed mean bias(SD,95%CI) for DiaSorin -0.6%(6.2,-12.8 to 11.6) and LC-MS/MS of +1.3%(7.4,-13.3 to 15.8) against their respective method group means. Comparison of measurements in the adult samples showed a strong correlation (r2=0.9331) and concordance (CCC=0.959) between the two methods. LC-MS/MS values were lower than DiaSorin by an overall mean(±SD,95%CI) of -1.6(±14.3,-29.6 to 26.5)pmol/L with an increased negative bias at higher concentrations. In the paediatric samples, weaker correlation (r2=0.6536) and concordance (CCC=0.782) were observed, with greater bias mean(±SD,95%CI) of -9.8(±23.4,-55.7 to 35.9)pmol/L. The variability in the paediatric samples was not associated with concentration or participant age. There was an increase in the correlation and concordance when 1,25(OH)2D2 was included in the analysis. Conclusions: It is likely that the metabolites of vitamin D present in the paediatric population contributed to the measurement of 1,25(OH)2D. The inconsistent agreement highlights the need for better assay harmonisation and paediatric reference intervals using LC-MS/MS method.

Item Type:	Article
Additional Information:	Data availability: The datasets generated and analysed during the current study are not publicly available due to data protection. Data request is subject to approval.
Faculty \ School:	Faculty of Medicine and Health Sciences > Norwich Medical School Faculty of Science > School of Biological Sciences
UEA Research Groups:	Faculty of Medicine and Health Sciences > Research Groups > Musculoskeletal Medicine Faculty of Medicine and Health Sciences > Research Centres > Metabolic Health
Depositing User:	LivePure Connector
Date Deposited:	06 Dec 2024 01:42
Last Modified:	17 Dec 2024 01:42
URI:	https://ueaeprints.uea.ac.uk/id/eprint/97925
DOI:	10.1515/cclm-2024-1032

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