Properties of stored RBCs: minimization of immune and vascular reactivity

描述(由申请人提供)： 输血是对急性失血或血液系统紊乱患者的一种救命干预措施，在美国，每年约有500万人接受红细胞输注。虽然输血显然对有需要的人有帮助，但输血的免疫和炎症副作用可能会对输血接受者产生有害的后果。最近的临床研究表明，在一些患者群体中，较老的RBC单位可能与预后恶化有关。这项研究建议的目的是发现在存储的RBC单位中发生的变化，并测试逆转或防止这些变化的方法。这项研究的主旨将是确定红细胞单位如何影响输血接受者的先天和获得性免疫反应以及血管反应性，以及红细胞单位的储存如何改变这些输血效应。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接受者的临床结果相关联。 这一建议背后的广泛假设是，红细胞的储存增加了它们调节免疫反应和激活输血接受者血管内皮细胞的能力。在整个储存过程中，白细胞减少的红细胞单位将具有调节先天和适应性免疫反应的能力。将使用尖端流动细胞技术测量红细胞与内皮细胞的相互作用，以测量红细胞与内皮细胞黏附的频率和强度，并测量暴露在新鲜和储存的红细胞单位中的内皮细胞的激活情况。在确定了储存的红细胞的免疫调节和血管激活特性的变化后，将探索防止这些变化的方法。在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分泌的T细胞亚群的偏斜。为了测试研究结果的体内相关性，在随机临床试验中，所测量的免疫参数将扩展到接受短期和长期储存的红细胞单位的受试者，相关的免疫参数将与疾病结果相关(例如，免疫抑制是否与感染并发症有关？)。 这项研究计划加入了一个具有互补专业知识的研究团队，以显著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红细胞储存的依赖的知识。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，红细胞在美国储存长达42天，然后才被输注给患者。这项建议测试红细胞储存是否会导致这些细胞的变化，这可能对输血接受者有害，并探索了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.