Department of Clinical Chemistry, University of Liege, CHU de Liege, CIRM, Liege, Belgium.
Centre for Research into Cancer Prevention and Screening, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland.
Clin Chem Lab Med. 2023 Mar 31;61(9):1561-1566. doi: 10.1515/cclm-2023-0176. Print 2023 Aug 28.
The exploration of the metabolites in the degradation pathways of vitamin D (VTD) has gained importance in recent years and simultaneous quantitation of twenty-five-hydroxy vitamin D (25(OH)D) mass concentration together with 24,25-dihydroxyvitamin D (24,25(OH)2D) has been proposed as a newer approach to define VTD deficiency. Yet, no data are available on 24,25(OH)2D biological variation (BV). In this study, we evaluated 24,25(OH)2D's BV on the European Biological Variation Study (EuBIVAS) cohort samples to determine if analytical performance specifications (APS) for 24,25(OH)2D could be generated.
Six European laboratories recruited 91 healthy participants. 25(OH)D and 24,25(OH)2D concentrations in K-EDTA plasma were examined weekly for up to 10 weeks in duplicate with a validated LC-MS/MS method. The Vitamin D Metabolite Ratio (24,25(OH)2D divided by 25(OH)D × 100) was also calculated at each time point.
Linear regression of the mean 24,25(OH)2D concentrations at each blood collection showed participants were not in steady state. Variations of 24,25(OH)2D over time were significantly positively associated with the slopes of 25(OH)D concentrations over time and the concentration of 25(OH)D of the participant at inclusion, and negatively associated with body mass index (BMI), but not with age, gender, or location of the participant. The variation of the 24,25(OH)2D concentration in participants over a 10 weeks period was 34.6%. Methods that would detect a significant change linked to the natural production of 24,25(OH)2D over this period at p<0.05 would need a relative measurement uncertainty (%)<14.9% while at p<0.01, relative measurement uncertainty should be <10.5%.
We have defined for the first time APS for 24,25(OH)2D examinations. According to the growing interest in this metabolite, several laboratories and manufacturers might aim to develop specific methods for its determination. The results presented in this paper are thus necessary prerequisites for the validation of such methods.
近年来，人们对维生素 D（VTD）降解途径中的代谢物的探索变得越来越重要，同时定量检测 25-羟维生素 D（25（OH）D）的质量浓度以及 24,25-二羟维生素 D（24,25（OH）2D）已被提议作为定义 VTD 缺乏的一种新方法。然而，目前尚无关于 24,25（OH）2D 生物学变异（BV）的数据。在本研究中，我们评估了欧洲生物变异研究（EuBIVAS）队列样本中 24,25（OH）2D 的 BV，以确定是否可以为 24,25（OH）2D 生成分析性能规格（APS）。
6 家欧洲实验室招募了 91 名健康参与者。使用经过验证的 LC-MS/MS 方法，每周在 K-EDTA 血浆中重复检测 25（OH）D 和 24,25（OH）2D 浓度，最多 10 周。在每个时间点还计算了维生素 D 代谢物比值（24,25（OH）2D 除以 25（OH）D×100）。
在每次采血时，对 24,25（OH）2D 平均浓度的线性回归表明，参与者未处于稳定状态。24,25（OH）2D 的时间变化与 25（OH）D 浓度随时间的斜率显著正相关，与参与者纳入时的 25（OH）D 浓度以及体重指数（BMI）显著负相关，但与年龄、性别或参与者的位置无关。参与者在 10 周期间 24,25（OH）2D 浓度的变化为 34.6%。在 p<0.05 时，检测到与 24,25（OH）2D 自然产生相关的显著变化的方法，需要相对测量不确定度（%）<14.9%，而在 p<0.01 时，相对测量不确定度应<10.5%。
我们首次定义了 24,25（OH）2D 检查的 APS。鉴于人们对这种代谢物的兴趣日益浓厚，可能有几家实验室和制造商旨在开发专门用于测定它的方法。因此，本文提出的结果是验证这些方法的必要前提。
