Improving Anticoagulation Monitoring in Pediatric Patients: Use of a Microfluidic Platform to Test Low Volume Blood Samples Obtained by Heel-Stick Collection

摘要 改善儿科患者的抗凝监测：使用微流控平台测试低容量 通过足跟采血棒采集血样 治疗先天性心脏病或其他高凝障碍的儿童处方为普通 在整个手术治疗过程中使用肝素（UFH）或低分子量肝素（LMWH）;可开具处方 术后2周内使用肝素，以防止血栓形成。UFH是一种非常有效的抗凝剂， 随着时间的推移，应密切监测，以确保适当的剂量和患者的反应; LMWH是一种较新的 抗凝血剂在心脏病专家中越来越受欢迎。尽管需要持续监测肝素 水平，有时每4小时，有限制，目前可用的系统阻碍交付的最佳 肝素水平结果给医生。这些障碍包括使用相对大量的生物活性剂的单独测定。 血液（每次检测约2 mL）和测量之间的长周转时间（长达2小时）限制了实用性 这些测试的适当剂量，特别是在抗凝治疗的开始。此外，本发明还提供了一种方法， 通常使用的测定（部分凝血活酶时间（PTT）、活化PTT（aPTT）和凝血酶原时间）显示 与患者输注的肝素水平相关性较差，但由于其历史价值和广泛应用， 在外地收养。需要更快速、更准确的方法来评估肝素水平， 血液总量，并为医生提供足够的剂量信息，以提供最佳治疗， 儿科患者。 通过先前资助的NIH快速通道项目，我们开发了一个新颖的可扩展平台， 通过测量凝血因子Xa（FXa）和抗- 凝血酶III（ATIII）水平。为了回应主要意见领袖的意见，我们正在开发第三种分析方法， aPTT。该测定组在我们的近患者数字微流体（DMF）平台上使用50 μ L全血运行 输入.荧光分析使用纳升体积的样品和试剂， 弹药筒虽然该平台已经开发，并且已经用测定法证明了可行性， 为了使该产品商业化，还有许多工作要做。通过这种商业化融资 准备就绪试点（CRP）将支持研究，以建立可靠的试剂和检测盒生产工艺， 临床前研究，以验证生产工艺，并制定FDA监管策略， 一项完整的多中心临床方法比较研究。 我们与波士顿儿童医院的持续合作加强了我们的方法， 测试的临床影响，以及全面的分析和全球经销商关系，证明了 市场缺口。DMF肝素监测产品将填补儿科护理的关键空白， 廉价的快速、低血容量系统，用于全面评估医院中的肝素水平，或 诊所设置成功完成这些CRP目标将加速商业发展， 准备立即完成监管批准和商业化的最终验证研究。

ABSTRACT Improving Anticoagulation Monitoring in Pediatric Patients: Use of a Microfluidic Platform to Test Low Volume Blood Samples Obtained by Heel-Stick Collection Children treated for congenital heart defects or other disorders of hypercoagulation are prescribed unfractionated heparin (UFH) or low molecular weight heparin (LMWH) throughout surgical treatment; they may be prescribed heparin for up to 2 weeks post-surgery to prevent thrombosis. UFH is a fiscally efficient, effective anticoagulant that should be closely monitored over time to ensure proper dosage and patient response; LMWH is a newer anticoagulant that is gaining traction among cardiologists. Despite the need for constant monitoring of heparin levels, sometimes every 4 hours, there are limitations to currently available systems hindering delivery of optimal heparin level results to physicians. These barriers include individual assays that use relatively large volumes of blood (~2 mL per assay) and long turnaround times between measurements (up to 2 hours) that limit the utility of these tests for appropriate dosing, especially in the beginning of anticoagulation therapy. In addition, commonly utilized assays (partial thromboplastin time (PTT), activated PTT (aPTT), and prothrombin time) show poor correlation to heparin levels infused in patients, but are still in use due to their historical value and wide adoption in the field. More rapid and accurate methods are needed to assess heparin levels that reduce the overall amount of blood and provide physicians with sufficient dosing information to deliver optimal therapy to pediatric patients. Through a previously funded NIH Fast-Track project, we developed a novel and scalable platform to assess and monitor heparin therapy administered to pediatric patients through measurement of Factor Xa (FXa) and Anti- thrombin III (ATIII) levels. In response to input from key opinion leaders, we are developing a third assay for aPTT. This assay panel is run on our near-patient digital microfluidic (DMF) platform using 50 L of whole blood input. The fluorescent assays use nanoliter volumes of sample and reagents on a disposable single-use cartridge. Although the platform has been developed and feasibility has been demonstrated with the assays, much work remains for this product to be commercially ready. Funding through this Commercialization Readiness Pilot (CRP) will support studies to establish reliable reagent and cartridge manufacturing processes, preclinical studies to validate the manufacturing processes, and development of the FDA regulatory strategy for a full multi-site clinical method comparison study. Our approach is strengthened by our continued partnership with Boston Children’s Hospital, the high potential clinical impact of the tests, and thorough analysis and global distributor relationships demonstrating a significant market gap. The DMF heparin monitoring product will fill a critical gap in pediatric care by providing an inexpensive rapid, low-blood volume system for comprehensive assessment of heparin levels in a hospital or clinic setting. The successful completion of these CRP aims will accelerate commercial development so that we are poised to immediately complete final validation studies for regulatory approval and commercial.