Properties of stored RBCs: minimization of immune and vascular reactivity

描述（由申请人提供）： 输血是急性失血或血液学紊乱受试者的救命干预措施，在美国每年约有500万人接受红细胞输注。虽然输血显然可以帮助那些有需要的人，但输血的免疫和炎症副作用可能会对输血接受者产生不利影响。最近的临床研究表明，在某些患者人群中，较旧的RBC单位可能与恶化的结局相关。这项研究计划的目的是发现储存的RBC单位中发生的变化，并测试逆转或防止这些变化的方法。研究的重点将是确定红细胞单位如何影响输血受体的先天性和适应性免疫反应和血管反应性，以及红细胞单位的储存如何改变这些输血效果。除了详细的体外研究外，该提案还将在一项临床试验的参与者中探索这些相同的参数，该试验将血液年龄与危重输血受者的临床结果相关联。 这一提议背后的广泛假设是，RBC的储存增加了它们调节免疫应答和激活输血受体中血管内皮细胞的能力。将在整个储存期间表征白细胞减少的RBC单位调节先天性和适应性免疫应答的能力。 将使用先进的流动池技术测量RBC-内皮细胞相互作用，以测量RBC与内皮细胞粘附的频率和强度，并测量暴露于新鲜和储存RBC单位的内皮细胞的活化。在确定了储存红细胞的免疫调节和血管活化特性的变化后，将探讨预防这些变化的方法。RBC暴露后将进行复杂的免疫学测量，包括T细胞和中性粒细胞中细胞因子/趋化因子诱导的多重测量、增殖反应的诱导以及调节性和IL-17分泌性T细胞亚群的偏移。为了检测研究结果的体内相关性，将测量的免疫参数扩展至随机临床试验中接受短期与长期储存RBC单位的受试者，相关免疫参数将与疾病结局相关（例如，免疫抑制是否与感染性并发症相关？）。 这项研究提案加入了一个具有互补专业知识的研究人员团队，以显着提高我们对输血的潜在有害免疫调节和血管激活作用及其对RBC储存的依赖性的认识。重要的是，该提案将验证在人体临床试验中获得的知识和开发的系统，并将评估使用体外系统预防红细胞储存有害影响的方法。 公共卫生相关性： 目前，红细胞在输注给患者之前在美国储存长达42天。该提案测试红细胞的储存是否会导致这些细胞发生可能对输血接受者有害的变化，并探索防止红细胞储存的任何有害影响的方法。

DESCRIPTION (provided by applicant): Blood transfusion is a life-saving intervention for subjects with acute blood loss or hematological disturbance, and approximately 5 million people per year receive red blood cell transfusions annually in the US. While blood transfusions clearly help those in need, the immune and inflammatory side-effects of transfusions may have detrimental consequences in transfusion recipients. Recent clinical studies suggest that older RBC units may be associated with worsened outcome in some patient populations. The purpose of this research proposal is to discover changes that occur in stored RBC units and test methods of reversing or preventing these changes. The thrust of the research will be to define how RBC units affect innate and adaptive immune responses and vascular reactivity in transfusion recipients and how storage of RBC units can alter these transfusion effects. In addition to detailed in vitro studies, the proposal will explore these same parameters in participants of a clinical trial correlating age of blood with clinical outcome in critically ill transfusion recipients. The broad hypothesis behind this proposal is that storage of RBCs increases their ability to modulate immune responses and to activate vascular endothelial cells in transfusion recipients. Leukoreduced RBC units will be characterized throughout storage for the ability to modulate innate and adaptive immune responses. RBC-endothelial cell interaction will be measured using cutting-edge flow cell technology to measure the frequency and strength of RBC adhesion to endothelial cells and to measure the activation of endothelial cells exposed to fresh and stored RBC units. After defining the changes in the immunomodulatory and vasoactivating properties of stored RBCs, methods of preventing these changes will be explored. Sophisticated immunology measurements will be made after RBC exposure, including multiplex measurement of cytokine/chemokine induction in T cells and neutrophils, induction of proliferative responses, and skewing of regulatory and IL-17 secreting T cell subsets. To test the in vivo relevance of the study findings, the immune parameters measured will be extended to subjects receiving RBC units stored for short vs. long periods in a randomized clinical trial, and relevant immune parameters will be correlated with disease outcome (e.g. is immune suppression linked with infectious complications?). This research proposal joins a team of investigators with complementary expertise to significantly advance our knowledge of potentially harmful immunomodulatory and vasoactivating effects of transfusion and their dependence on storage of RBCs. Importantly, the proposal will validate the knowledge gained and systems developed in a human clinical trial and will evaluate methods of preventing harmful effects of RBC storage using in vitro systems. PUBLIC HEALTH RELEVANCE: Red blood cells are currently stored in the US for up to 42 days prior to being transfused to patients. This proposal tests whether or not storage of red blood cells causes changes in these cells that might be harmful to transfusion recipients and explores ways of preventing any harmful effects of red blood cell storage.