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 高跟棒采集法采集的血样 治疗先天性心脏病或其他高凝障碍的儿童被开出不分部位的处方。 在整个外科治疗过程中使用肝素(UFH)或低分子肝素(LMWH)；可以开它们的处方 术后使用肝素最多2周以预防血栓形成。UFH是一种经济上有效的抗凝剂 应该随着时间的推移密切监测，以确保适当的剂量和患者的反应；低分子肝素是一种较新的药物 在心脏病专家中获得关注的抗凝血剂。尽管需要持续监测肝素 水平，有时每4小时，当前可用的系统存在限制，阻碍了最佳 将肝素水平结果告知医生。这些障碍包括使用相对大量的 血液(每次化验约2毫升)和两次测量之间较长的周转时间(长达2小时)，限制了该方法的实用性 这些测试中的适当剂量，特别是在抗凝治疗开始时。此外, 常用的检测方法(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，仍在使用 在野外领养。需要更快速和准确的方法来评估降低肝素水平的肝素水平 并为医生提供充分的剂量信息，以提供最佳治疗 儿科病人。 通过之前资助的NIH快速通道项目，我们开发了一个新的、可扩展的平台来评估和 应用凝血因子Xa(FXA)和抗-HBs监测儿童肝素治疗 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，以 APTT。该分析小组运行在我们的近患者数字微流控(DMF)平台上，使用50L全血 输入。荧光分析在一次性使用时使用纳升体积的样品和试剂 弹药筒。虽然已经开发了平台，并通过检测证明了可行性， 这款产品要商业化还有很多工作要做。通过此商业化提供资金 就绪性试点(CRP)将支持建立可靠试剂和试剂盒制造工艺的研究， 临床前研究，以验证生产过程，并制定FDA的监管战略 一项完整的多部位临床方法对比研究。 我们与波士顿儿童医院的持续合作伙伴关系加强了我们的方法，具有很高的潜力 测试的临床影响，以及彻底的分析和全球经销商关系显示出显著的 市场缺口。DMF肝素监测产品将通过提供 廉价、快速、低血容量的系统，用于全面评估医院或医院的肝素水平 诊所环境。这些目标的成功实现将加速商业发展，使我们 准备立即完成最终验证研究，以获得监管部门的批准和商业应用。

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.