Multi-modal assessment of liver grafts undergoing normothermic machine perfusion to stratify quality and deliver therapy

肝移植是终末期肝病患者的治愈性治疗，但全球供体器官短缺意味着许多患者在等待合适的肝脏时死亡。为了解决这个问题，通常考虑合并症增加的老年供体的肝脏和循环死亡后捐献的肝脏。由于对功能和外观的担忧，这些肝脏中的许多都拒绝移植。关键的决定是基于稀缺的功能数据availableat时间的捐赠和主观外观的判断，检索surgics.Normothemic灌注技术，现在越来越多地应用于临床实践，似乎提高利用器官移植，并提供更好的临床结果。肝脏的常温灌注使器官在体外保持功能状态，并在正常体温下输送氧气和营养物质长达一周。这使得可以动态评估器官的功能，增加外科医生使用器官的信心。目前这种评估是基于有限的生化参数。器官的常温灌注提供了几个尚待在临床环境中开发的额外机会，其中包括深入评估肝脏质量和功能，直接向肝脏输送新疗法以及评估这些疗法如何影响器官的质量和功能。我们希望通过灌注从同意的捐赠者那里获得的用于移植的人体器官来探索其中的一些机会。首先，我们希望结合成像模式（如拉曼光谱或多路复用多传感光纤）和使用蛋白质组学、无细胞DNA、单细胞测序等技术分析肝脏的代谢功能，对肝脏进行真实的实时评估。这将使我们能够了解脑死亡（DBD）和循环死亡（DCD）如何影响肝脏及其各种细胞的差异，并开发潜在的治疗方法来靶向和修复这些负面影响。其次，我们希望将细胞疗法直接输送到肝脏，同时在机器上保持活力。我们将专注于项目第一部分中确定的旨在改善肝脏质量的疗法，并从不适合人类移植的肝脏中分离用于这些疗法的细胞，以最大限度地利用器官。在该项目的第一阶段开发的模式评估策略，我们将评估这些疗法在改善肝脏质量方面的有效性。如果器官移植后，我们将使用机器学习和信息学来分析这些检测产生的数据，并与移植后的临床结果相关联。如果临床医生发现这些器官不适合，并且有近亲同意使用这些器官进行研究，我们将从这些肝脏中分离细胞用于治疗。这项拟议的研究将产生新的临床相关生物标志物，并开发新的真实的时间技术，以深入评估肝脏移植物的质量和任何介入治疗的效果。这将具有显著的临床影响，允许增加器官利用并最大限度地减少器官丢弃。其次，建立肝源性细胞疗法的概念，并在机器灌注期间提供针对器官的治疗，将允许利用所有捐赠器官，并使器官修复中心的发展成为可能，在这些中心，这些疗法可以在适当的环境中提供，并使用开发的多模式评估工具评估其效果。

Liver transplantation is a curative treatment for patients with end stage liver disease but a global shortage of donor organs means that many patients die waiting for suitable liver. To address this, livers from older donors with increasing comorbidity and livers donated after circulatory death areroutinely considered. Many of these livers are turned down for transplantation due to concerns about function and appearance. The critical decisions are based on scarce functional data availableat the time of donation and subjective appearance as judged by the retrieving surgeons.Normothermic perfusion technology is now increasingly used in clinical practice and appears to improve the utilisation of organs for transplantation and provide better clinical outcomes. Normothermic perfusion of the liver maintains the organ in a functional state outside the body and delivers oxygen and nutrients at normal body temperature for up to a week. This allows a dynamic assessment of the function of the organ increasing surgeons' confidence to use the organ. At present this assessment is based on limited biochemical parameters.Normothermic perfusion of the organs offer several additional opportunities which are yet to be developed in the clinical setting, which include an in-depth assessment of liver quality and function, delivery of new therapies directly into the liver and evaluation of how these therapies affect the quality and function of the organ. We want to explore some of these opportunities by perfusing human organs retrieved for the purpose of transplantation from consenting donors.In the first instance, we want to assess the liver in real time combining imaging modalities (such as Raman spectroscopy or multiplex multi-sensing fiber optics) with analysis of the metabolic function of the liver using technologies such as proteinomics, cell free DNA, single cell sequencing. This will allow us to understand the difference in how brain death (DBD) and circulatory death (DCD) affect the livers and its various cells and develop potential therapies to target and repair these negative effects.Secondly, we want to deliver cell therapies directly into the liver whilst kept alive on the machine. We will focus on therapies directed at improving the quality of the liver as identified in the first part of the project and isolate the cells for these therapies from livers that are unsuitable for human transplantation to maximise organ utilisation.Using the multi-modal assessment strategies developed in the first stage of the project we will evaluate how effective these therapies are in improving the quality of the liver.If the organs are transplanted, we will use machine learning and informatics to analyse data generated from these assays and correlate with the clinical outcome post transplant. If the organs are found unsuitable by clinicians and there is the next of kin has consented to use these organs for research, we will isolate the cells from these liver to use as therapies.This proposed research will generate novel clinically relevant biomarkers and develop new real time technology to assess in depth the quality of the liver grafts and the effect of any interventional therapy. This will have a significant clinical impact allowing an increase in organ utilisation and minimise organ discard. Secondly, establishing the concept of liver derived cell therapies and delivery of therapies targeted to the organ during machine perfusion, will allow the utilisation of all donated organs and enable the development of organ repair centres where such therapies can be delivered in appropriate environments and their effects assessed using the multi-modal assessment tools developed.