Microsampling Assays for Immunosuppressive Drugs in Children

项目总结 免疫抑制治疗是坚固的器官和骨骼术后成功的长期结果的基础 骨髓/干细胞移植，以及作为包括类风湿在内的各种自体炎症条件的治疗 成人和儿童的关节炎、湿疹、牛皮癣、克罗恩病和肾病综合征。最理想的血液 这些药物的浓度对于最大限度地减少毒性和防止移植受者发生排斥反应至关重要。 这些药物需要频繁的、往往是终生的治疗性药物监测(TDM)，以确保剂量 维持最佳治疗浓度。用于指导给药的现行TDM(临床标准) 环孢素A(CyA)、他克莫司(TAC)和西罗莫司(SIR)的 液质联用(LC-MS/MS)分析。这需要免疫抑制。 患者需要到门诊实验室进行静脉采血，这可能会增加他们感染的风险。 开发一种简单易用、体积小的血液采样方法可以方便家庭采样和 减轻儿科患者及其家属负担。目前的TDM需要0.5到1.0毫升的全血， 通常是通过静脉抽液。使用Mitra装置或Tasso-M20装置的容量吸收微量采样(VAMS) 允许从毛细针头采集固定的小容量血液(例如，20微米L)，而不需要 做静脉抽液手术。在成人中使用Mitra装置的CyA、TAC和SIR的临床验证研究是最近的 据报道。虽然一项研究显示与TAC分析有很好的相关性，但另一项研究显示不一致 使用Mitra设备采集样本。因此，Mitra器件用于常规TDM的潜在用途是 不确定。FDA批准的Tasso-M20设备可实现准确、精确、无痛和一致的采集 一小部分固定的血液。然而，Tasso-M20设备在临床环境中的实施 TDM需要分析和临床验证。拟议的微量采样分析的目标是 儿童免疫抑制药物研究(处女期)：1)验证Tasso-M20 VAMS LC-MS/MS分析 对于CyA、TAC和SIR，2)评估CyA、TAC和SIR在Tasso-M20设备中在 运输和储存条件，3)临床验证Tasso-M20VAMS LC-MS/MS检测CyA，TAC， 和SIR对照目前儿科患者静脉全血TDM免疫测定，以及4)证实了稳定性 Tasso-M20 VAMS临床标本在运输和储存条件下的CyA、TAC和SIR。如果 这项研究的成功将使TDM的微量采样方法能够在临床上使用 (消除了侵入性静脉抽液的需要)，以及在家中(减轻家庭带来的负担 免疫抑制儿童走出家进行常规TDM)，并革命性地对TDM进行远程采样 儿童和成人的免疫抑制药物。

PROJECT SUMMARY Immunosuppressive therapy is the foundation of successful long-term outcomes after solid organ and bone marrow/stem cell transplants and as a treatment for various auto-inflammatory conditions, including rheumatoid arthritis, eczema, psoriasis, Crohn's disease, and nephrotic syndrome in adults and children. The optimal blood concentrations of these drugs are critical to minimize toxicity and to prevent rejection in transplant recipients. These drugs require frequent and often life-long therapeutic drug monitoring (TDM) to ensure that dosing maintains the optimal therapeutic concentrations. Current TDM (clinical standard) used for the dosing guidance of cyclosporine A (CYA), tacrolimus (TAC), and sirolimus (SIR) are derived from whole blood immunoassays or liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays. This requires immunosuppressed individuals to go to outpatient laboratories for phlebotomy, potentially increasing their risk of acquiring infections. The development of an easy-to-use, small volume, blood sampling approach can facilitate home sampling and reduce the burden on pediatric patients and their families. Current TDM requires 0.5 to 1.0 mL of whole blood, typically via phlebotomy. Volumetric absorptive microsampling (VAMS) with Mitra devices or Tasso-M20 devices allows for the collection of a fixed small volume of blood (e.g., 20 µL) from a capillary needle without the need for phlebotomy. Clinical validation studies for CYA, TAC, and SIR with Mitra devices in adults were recently reported. While one study showed a good correlation for TAC analysis, the other study showed inconsistency with sample collection using Mitra devices. Therefore, the potential utility of Mitra devices for routine TDM is uncertain. FDA-approved Tasso-M20 devices allow for an accurate, precise, painless, and consistent collection of a fixed small volume of blood. However, the implementation of Tasso-M20 devices into the clinical setting for TDM requires both analytical and clinical validation. The objectives of the proposed Microsampling Assays for Immunosuppressive Drugs in childrEN (MAIDEN) study is to: 1) validate Tasso-M20 VAMS LC-MS/MS assays for CYA, TAC, and SIR, 2) evaluate in vitro stability of CYA, TAC, and SIR in Tasso-M20 devices under the conditions of shipping and storage, 3) clinically validate Tasso-M20 VAMS LC-MS/MS assays for CYA, TAC, and SIR against current venous whole blood TDM immunoassays in pediatric patients, and 4) confirm the stability of CYA, TAC, and SIR in Tasso-M20 VAMS clinical samples under the conditions of shipping and storage. If successful, this research will enable the use of the microsampling method for TDM in the clinical setting (obviating the need for invasive phlebotomy), and at home (reducing the burden on families to bring the immunosuppressed children out of the home for routine TDM), and revolutionize remote sampling for TDM of immunosuppressant drugs in children and adults.