Department of Drug Chemistry, Pharmaceutical and Biomedical Analysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1, Warsaw, 02-097, Poland.
Therapeutic Drug Monitoring, Clinical Pharmacokinetics and Toxicology Laboratory Unit, Department of Clinical Biochemistry, The Children's Memorial Health Institute, Dzieci Polskich 20, Warsaw, 04-730, Poland.
Pharmacol Rep. 2024 Dec;76(6):1443-1455. doi: 10.1007/s43440-024-00663-9. Epub 2024 Oct 10.
The benefits of pharmacotherapy with sirolimus (SIR) in pediatric transplant recipients are well established. Traditionally, whole blood samples have been used to measure SIR concentrations. Volumetric Absorptive Microsampling (VAMS) is an alternative sampling strategy suitable for Therapeutic Drug Monitoring (TDM). In this study, we developed and validated two liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods for determining SIR concentrations in whole blood (WB) and capillary whole blood samples collected using a VAMS-Mitra™ device.
We used protein precipitation during WB sample preparation and dispersive liquid-liquid microextraction (DLLME) with methyl tert-butyl ether for VAMS sample preparation to optimise the analyte extraction process. The described validation protocols were cross-validated, confirming the equivalence of the whole-blood and VAMS-based methods. Furthermore, the developed methods were evaluated in two three-level rounds of an external proficiency-testing scheme.
The analytical methods were successfully validated within the calibration range of SIR (0.5-60 ng/ml). The validation parameters met the European Medicines Agency (EMA) and the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDM&CT) acceptance criteria. No hematocrit (tested in the range of 24.3-64.1%), matrix, or carry-over effects were observed. Cross-validation confirmed the interchangeability between VAMS-LC-MS/MS and WB-LC-MS/MS methods. The developed methods were successfully implemented for SIR determination in 140 clinical samples (70 each of WB and VAMS) from pediatric renal transplant recipients, demonstrating their practicality and reliability.
The VAMS-based method has been rigorously tested and is clinically equivalent to the reference WB-LC-MS/MS method. Additionally, clinical validation confirmed the utility of the presented methods for TDM of the SIR in the pediatric population after renal transplantation.
西罗莫司（SIR）在儿科移植受者中的药物治疗益处已得到充分证实。传统上，全血样本被用于测量 SIR 浓度。体积吸收微采样（VAMS）是一种适合治疗药物监测（TDM）的替代采样策略。在这项研究中，我们开发并验证了两种液相色谱-串联质谱（LC-MS/MS）方法，用于测量全血（WB）和使用 VAMS-Mitra™装置采集的毛细血管全血样本中的 SIR 浓度。
我们在 WB 样品制备过程中使用蛋白质沉淀，在 VAMS 样品制备中使用甲基叔丁基醚进行分散液-液微萃取（DLLME），以优化分析物提取过程。描述的验证方案经过交叉验证，确认了全血和基于 VAMS 的方法的等效性。此外，所开发的方法在外部能力验证计划的两个三级轮次中进行了评估。
SIR（0.5-60ng/ml）的分析方法在整个校准范围内均成功验证。验证参数符合欧洲药品管理局（EMA）和国际治疗药物监测和临床毒理学协会（IATDM&CT）的接受标准。未观察到红细胞压积（测试范围为 24.3-64.1%）、基质或携带效应。交叉验证证实了 VAMS-LC-MS/MS 和 WB-LC-MS/MS 方法之间的可互换性。所开发的方法已成功用于 140 份儿科肾移植受者的临床样本（WB 和 VAMS 各 70 份）中 SIR 的测定，证明了其实用性和可靠性。
VAMS 方法经过严格测试，与参考 WB-LC-MS/MS 方法在临床上等效。此外，临床验证证实了所提出的方法在儿科人群肾移植后 SIR 的 TDM 中的实用性。
