University of Michigan, Ann Arbor, MI;
Clin Chem. 2013 Nov;59(11):1630-7. doi: 10.1373/clinchem.2013.209114. Epub 2013 Jul 31.
LC-MS is increasingly used for therapeutic drug monitoring of tacrolimus. A recent summary from an international proficiency-testing scheme demonstrated that the mass spectrometry respondents were the largest method group. However, these methods lack standardization, which may explain the relatively poor interlaboratory agreement for such methods. This study aimed to provide one path toward the standardization of tacrolimus quantification by use of LC-MS.
A 40-member whole blood tacrolimus proficiency panel was circulated to 7 laboratories, 4 in the US and 3 in Europe, offering routine LC-MS-based quantification of tacrolimus. All laboratories used a common LC-MS platform and followed the manufacturer's instructions that accompanied an LC-MS reagent kit intended for tacrolimus quantification in whole blood samples. Four patient pools were prepared that had sufficient volume to allow comparison with a tacrolimus reference measurement procedure.
For the 40-member panel, the standardized MassTrak LC-MS assay demonstrated excellent agreement with a validated LC-MS method used by Analytical Services International (y = 1.02x - 0.02; r = 0.99). The CVs for the pooled patient samples ranged from 2.0% to 5.4%. The mean difference from the reference measurement procedure ranged from 0.4% to 4.4%.
Tacrolimus assay standardization, which must include all facets of the analysis, is necessary to compare patient results between laboratories and to interpret consensus guidelines. LC-MS can provide accurate and precise measurement of tacrolimus between laboratories.
LC-MS 越来越多地用于他克莫司的治疗药物监测。最近一项国际能力验证计划的总结表明，质谱法应答者是最大的方法组。然而，这些方法缺乏标准化，这可能解释了这些方法的实验室间一致性相对较差。本研究旨在为 LC-MS 定量他克莫司的标准化提供一条途径。
将一个由 40 名成员组成的全血他克莫司能力验证小组分发给 7 个实验室，其中 4 个在美国，3 个在欧洲，提供常规的基于 LC-MS 的他克莫司定量检测。所有实验室都使用共同的 LC-MS 平台，并遵循制造商的说明，该说明随附用于全血样品中他克莫司定量的 LC-MS 试剂试剂盒。准备了四个足够大体积的患者池，以便与他克莫司参考测量程序进行比较。
对于 40 名成员小组，标准化的 MassTrak LC-MS 测定法与 Analytical Services International 使用的经过验证的 LC-MS 方法显示出极好的一致性（y = 1.02x - 0.02；r = 0.99）。混合患者样本的 CV 范围为 2.0%至 5.4%。与参考测量程序的平均差值范围为 0.4%至 4.4%。
为了比较实验室之间的患者结果并解释共识指南，必须对分析的所有方面进行他克莫司检测标准化。LC-MS 可以在实验室之间提供准确和精确的他克莫司测量。
