Targeted, Highly Sensitive, Non-Invasive Cardiac Transplant Rejection Monitoring

描述(由申请者提供)：超过18万美国人生活在固体器官移植中。每年进行的心脏移植手术超过2000例，其中包括300多例儿童心脏移植手术，仅在美国就有2万多名在世的心脏移植受者。心脏移植后的一年存活率已经提高到90%以上；然而，10年存活率仍然不到60%。随着手术和术后管理的改进，排斥反应已成为影响预后的主要因素。及早发现排斥反应有助于及早治疗，从而改善早期和晚期功能和存活率。 监测心脏移植排斥反应的金标准仍然是基于导管的心内膜心肌活检(EMB)。为了及早发现排斥反应，必须定期进行监视活检；然而，EMB既昂贵(超过4000美元)，又具有侵入性(主要并发症为1.9%)。据估计，每年进行的监测活组织检查超过30,000例，确定了3,000例排斥反应和300多种主要并发症。迫切需要一种高度敏感、非侵入性的方法来可靠地检测出有排斥反应的患者。这一建议将对心脏移植的排斥监测问题产生重大影响，促进更早发现、更早治疗，并改善长期结果。实体器官排斥反应患者供体特异性cf-dna升高。我们在38名儿童和成人心脏移植患者中完成了一项盲法试点研究，使用了一种新的、高精度的靶向测序方法，该方法精确地量化了受者血浆中供者特定细胞游离DNA(cf-DNA)和总cf-DNA的数量。这一数据建立了一个阈值，低于这个阈值，没有样本发生排斥反应(0/51)，高于这个阈值，所有ISHLT e2级排斥反应(6/6)患者都能被检测到(100%敏感性)。我们已经组建了一个由6个主要的儿科和成人移植中心组成的联盟，进行一项具有独立病理学和ECHO核心实验室的盲法多中心研究，以测试这一极具前景、成本效益和创新的方法。我们将首先确定一个阈值并开发一个预测模型，然后对240名新的儿科和成人移植受者进行至少一年的纵向跟踪，在预期的和盲目的样本集上进行验证。最后，我们将探讨主要病理和临床观察与供者特异性和总cf-DNA水平之间的关系。这种方法有望在全固体器官移植中实现准确和经济有效的非侵入性排斥检测。

DESCRIPTION (provided by applicant): Over 180,000 Americans are living with solid organ transplants. Each year over 2000 heart transplants, including over 300 pediatric heart transplants are performed resulting in over 20,000 living heart transplant recipients in the U.S. alone. One year survival following heart transplantation has improved to over 90%; however, 10 year survival remains less than 60%. With improvement in operative and postoperative management, rejection has become the major determinant of outcome. Earlier detection of rejection facilitates earlier treatment, which improves both early and late function and survival. The gold standard in surveillance of cardiac allograft rejection remains catheter based endomyocardial biopsy (EMB). To detect rejection early, surveillance biopsies must be performed at regular intervals; however, EMB is both expensive (over $4000) and invasive (major complications 1.9%). It is estimated that over 30,000 surveillance biopsies are performed each year identifying 3,000 rejections with over 300 major complications. There is a tremendous need for a highly sensitive, non-invasive method that reliably detects patients with rejection. This proposal will have high impact on the problem of rejection surveillance in cardiac transplantation promoting earlier detection, earlier treatment, and improved long term outcomes. Donor specific cf-DNA increases in patients with solid organ rejection. We have completed a blinded pilot study in 38 pediatric and adult heart transplant patients utilizing a novel, highly accurate, targeted sequencing approach which precisely quantifies the amount of donor specific cell free DNA (cf-DNA) and total cf-DNA in recipient plasma. This data established a threshold below which no sample had rejection (0/51), and above which all patients with ISHLT grade e2 rejection (6/6) were detected (100% sensitivity). We have assembled a consortium of 6 major pediatric and adult transplant centers for a blinded multi-center study with independent pathology and echo core labs to test this extremely promising, cost effective, and innovative approach. We will first determine a threshold and develop a predictive model and then validate both on a prospective and blinded sample set of 240 new pediatric and adult transplant recipients followed longitudinally for at least one full year. Finally we will explore the relationships between major pathologic and clinical observations and levels of donor specific and total cf-DNA. This method holds promise to enable the accurate and cost effective non- invasive determination of rejection in all solid organ transplantation.