North West London Pathology, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London W6 8RF, United Kingdom.
DEQAS Advisory Panel, Charing Cross Hospital, London W6 8RF, United Kingdom.
J Steroid Biochem Mol Biol. 2020 Jun;200:105639. doi: 10.1016/j.jsbmb.2020.105639. Epub 2020 Feb 19.
The Vitamin D External Quality Assessment Scheme (DEQAS) distributes serum samples globally, on a quarterly basis, to assess participants' performance of specific methods for 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25-(OH)D). DEQAS occasionally circulates samples containing high levels of substances found in certain clinical situations e.g. 25-OHD, 24,25-(OH)D, hypertriglyceridemia. The increased availability and use of health supplements containing biotin has led to case reports of assay interference in methods utilizing a biotin-streptavidin detection system. In October 2018, DEQAS included a serum sample (545) containing exogenous biotin (concentration =586 μg/L) which was analyzed by a total of 683 laboratories using 35 different methods. The same serum sample (544) without exogenous biotin was also included in the 5-sample set. All methods (760 laboratories) performed satisfactorily on sample 544 giving an All-Laboratory Trimmed Mean = 50.2 ± 6.5 nmol/L (±SD, CV = 12.9 %). The target value for this sample 544 (& 555) was 47.4 nmol/L as determined by Centers for Disease Control and Prevention (CDC) Atlanta, Georgia using their LC-MS/MS reference method. In contrast, #545 containing the exogenous biotin was reported by only 683 laboratories and gave an All-Laboratory Trimmed Mean = 66.8 ± 37.6 nmol/L (±SD, CV = 56.3 %). As expected, LC-MS/MS methods (143 labs) reported similar results for both 544 = 48.9 ± 4.4 nmol/L (±SD) and 545 = 48.3 ± 4.5 nmol/L (±SD) showing that assays involving chromatographic steps are unaffected by the presence of biotin. Several of the antibody-based assays including Abbott Architect, DiaSorin Liaison, Beckman Unicel and Siemens Centaur are also unaffected by the addition of biotin. Two assays, IDS-iSYS and Roche Total 25OHD, both of which use biotin-streptavidin, exhibit biotin interference yielding values with a significant positive bias for 545 of 102.6 nmol/L ± 78.7 nmol/L (±SD) and 517.8 nmol/L ± 209.8 nmol/L (±SD) respectively. Interestingly, the failure to report sample 545 data from 77 laboratories is due solely to those running Roche Total 25OHD or Roche Vitamin D Total II assays. Given the prevalence of the adversely affected assays (25 % of DEQAS users) and the high volume of 25OHD testing, clinicians using these assays should, where possible, only measure 25OHD when patients are off biotin.
维生素 D 外部质量评估计划（DEQAS）每季度在全球范围内分发血清样本，以评估参与者对特定方法检测 25-羟维生素 D（25OHD）和 1,25-二羟维生素 D（1,25-(OH)D）的性能。DEQAS 偶尔会分发含有某些临床情况下存在的物质（例如 25-OHD、24,25-(OH)D、高甘油三酯血症）水平较高的样本。含有生物素的保健品的广泛使用导致了利用生物素-链霉亲和素检测系统的方法出现检测干扰的病例报告。2018 年 10 月，DEQAS 纳入了一份含有外源性生物素（浓度=586μg/L）的血清样本（545），共有 683 个实验室使用 35 种不同的方法对其进行了分析。同一血清样本（544）不含外源性生物素，也包含在 5 个样本集中。所有方法（760 个实验室）在样本 544 上均表现良好，所有实验室 trimmed 平均值=50.2±6.5nmol/L（±SD，CV=12.9%）。该样本的目标值为 47.4nmol/L，由佐治亚州亚特兰大疾病控制与预防中心（CDC）使用他们的 LC-MS/MS 参考方法确定。相比之下，仅 683 个实验室报告了含有外源性生物素的样本 545，其所有实验室 trimmed 平均值=66.8±37.6nmol/L（±SD，CV=56.3%）。正如预期的那样，LC-MS/MS 方法（143 个实验室）对 544（=48.9±4.4nmol/L（±SD）和 545（=48.3±4.5nmol/L（±SD））的报告结果相似，表明涉及色谱步骤的检测不受生物素的影响。包括 Abbott Architect、DiaSorin Liaison、Beckman Unicel 和 Siemens Centaur 在内的几种基于抗体的检测方法也不受生物素的影响。两种检测方法，IDS-iSYS 和 Roche Total 25OHD，均使用生物素-链霉亲和素，表现出生物素干扰，545 的值呈显著正偏倚，为 102.6nmol/L±78.7nmol/L（±SD）和 517.8nmol/L±209.8nmol/L（±SD）。有趣的是，77 个实验室未能报告样本 545 的数据，这仅仅是因为它们运行罗氏 Total 25OHD 或罗氏维生素 D 总 II 检测。鉴于受不利影响的检测方法的普遍性（DEQAS 用户的 25%）和 25OHD 检测的高数量，使用这些检测方法的临床医生应尽可能在患者停用生物素时仅测量 25OHD。
