학술논문
Assessment of serum total 25-hydroxyvitamin D assay commutability of Standard Reference Materials and College of American Pathologists Accuracy-Based Vitamin D (ABVD) Scheme and Vitamin D External Quality Assessment Scheme (DEQAS) materials: Vitamin D Standardization Program (VDSP) Commutability Study 2
Document Type
Article
Author
Camara, Johanna E.; Wise, Stephen A.; Hoofnagle, Andrew N.; Williams, Emma L.; Carter, Graham D.; Jones, Julia; Burdette, Carolyn Q.; Hahm, Grace; Nalin, Federica; Kuszak, Adam J.; Merkel, Joyce; Durazo-Arvizu, Ramón A.; Lukas, Pierre; Cavalier, Étienne; Popp, Christian; Beckert, Christian; Schultess, Jan; Van Slooten, Glen; Tourneur, Carole; Pease, Camille
Source
Subject
*LIQUID chromatography-mass spectrometry
*VITAMIN D
*BINDING site assay
*LIGAND binding (Biochemistry)
*REFERENCE sources
*PATHOLOGISTS
*STANDARDIZATION
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Language
ISSN
1618-2642
Abstract
An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum total 25-hydroxyvitamin D [25(OH)D] using ligand binding assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A set of 50 single-donor serum samples were assigned target values for 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] using reference measurement procedures (RMPs). SRM and PT/EQA samples evaluated included SRM 972a (four levels), SRM 2973, six College of American Pathologists (CAP) Accuracy-Based Vitamin D (ABVD) samples, and nine Vitamin D External Quality Assessment Scheme (DEQAS) samples. Results were received from 28 different laboratories using 20 ligand binding assays and 14 LC-MS/MS methods. Using the test assay results for total serum 25(OH)D (i.e., the sum of 25(OH)D2 and 25(OH)D3) determined for the single-donor samples and the RMP target values, the linear regression and 95% prediction intervals (PIs) were calculated. Using a subset of 42 samples that had concentrations of 25(OH)D2 below 30 nmol/L, one or more of the SRM and PT/EQA samples with high concentrations of 25(OH)D2 were deemed non-commutable using 5 of 11 unique ligand binding assays. SRM 972a (level 4), which has high exogenous concentration of 3-epi-25(OH)D3, was deemed non-commutable for 50% of the LC-MS/MS assays. [ABSTRACT FROM AUTHOR]