Burdette Carolyn Q, Camara Johanna E, Nalin Federica, Pritchett Jeanita, Sander Lane C, Carter Graham D, Jones Julia, Betz Joseph M, Sempos Christopher T, Wise Stephen A
National Institute of Standards and Technology, Chemical Sciences Division, Gaithersburg, MD 20899.
Imperial College Healthcare, Department of Biochemistry, NHS Trust, Charing Cross Hospital, London, United Kingdom.
J AOAC Int. 2017 Sep 1;100(5):1277-1287. doi: 10.5740/jaoacint.17-0306. Epub 2017 Aug 29.
Until recently, the Vitamin D External Quality Assessment Scheme (DEQAS) assessed the performance of various assays for the determination of serum total 25-hydroxyvitamin D [25(OH)D] by using a consensus mean based on the all-laboratory trimmed mean (ALTM) of the approximately 1000 participants' results. Since October 2012, the National Institute of Standards and Technology (NIST), as part of the Vitamin D Standardization Program, has participated in DEQAS by analyzing the quarterly serum sample sets using an isotope dilution LC-tandem MS (ID LC-MS/MS) reference measurement procedure to assign an accuracy-based target value for serum total 25(OH)D. NIST has analyzed 90 DEQAS samples (18 exercises × 5 samples/exercise) to assign target values. The NIST-assigned values are compared with the ALTM and the biases assessed for various assays used by the participants, e.g., LC-MS/MS, HPLC, and several ligand-binding assays. The NIST-value assignment process and the results of the analyses of the 90 DEQAS samples are summarized. The absolute mean bias between the NIST-assigned values and the ALTM was 5.6%, with 10% of the samples having biases >10%. Benefits of the accuracy-based target values are presented, including for sample sets with high concentrations of 25(OH)D2 and 3-epi-25(OH)D3.
直到最近，维生素D外部质量评估计划（DEQAS）通过使用基于约1000名参与者结果的所有实验室截尾均值（ALTM）的共识均值，来评估各种血清总25-羟基维生素D [25(OH)D]测定方法的性能。自2012年10月以来，作为维生素D标准化计划的一部分，美国国家标准与技术研究院（NIST）通过使用同位素稀释液相色谱-串联质谱（ID LC-MS/MS）参考测量程序分析季度血清样本集，为血清总25(OH)D指定基于准确度的目标值，从而参与了DEQAS。NIST已分析了90个DEQAS样本（18次检测×每次检测5个样本）以指定目标值。将NIST指定的值与ALTM进行比较，并评估参与者使用的各种检测方法（例如LC-MS/MS、HPLC和几种配体结合检测方法）的偏差。总结了NIST值指定过程以及对90个DEQAS样本的分析结果。NIST指定值与ALTM之间的绝对平均偏差为5.6%，10%的样本偏差>10%。介绍了基于准确度的目标值的益处，包括对于高浓度25(OH)D2和3-表-25(OH)D3样本集的益处。
