Biomarkers of Inflammation and Vaso-occlusion in Sickle Cell Disease

描述（由申请人提供）：为了鉴定新的生物标志物以评估镰状细胞病（SCD）患者的状态，我们组建了一个由5名主要研究者组成的团队，他们的专业知识包括临床研究、免疫学、生物医学工程和微血管成像。我们提出的总体假设是，SCD中组织损伤的严重程度与炎症和血管灌注状态有关。我们的目标是将微创技术应用于敏感地评估炎症和微血管闭塞以分析小鼠和人SCD：1）患者血液的流式细胞术以测量iNKT细胞活化;和2）对比增强超声（CEU）以测量小鼠和人中的原位血管体积/灌注。这些都是从免疫学和心脏病学领域借来的经过验证的安全技术。我们将这些措施与其他疾病指标，如临床状况的人和肺功能和活体显微镜在小鼠。我们最近发现，iNKT细胞，这可以通过激活腺苷A2 A受体（A2 AR）的抑制，被激活的小鼠或患有SCD的人。我们启动了一项正在进行的临床研究（NIH RC 2 HL 101367），这是由FDA批准的A2 AR激动剂regadenoson药物的可用性促成的。另一项正在进行的SCD临床试验正在评估GMI-1070，一种泛选择素抑制剂，以减少白细胞粘附到内皮细胞（EC）和血管闭塞发作。为了更深入地研究白细胞-EC相互作用，我们招募了粘附分子和活体显微镜的权威。为了研究小鼠和人的微血管灌注，我们招募了CEU技术专家来测量小鼠和人研究中的血管灌注。数以百万计的患者接受了CEU来测量心脏和其他组织中的血管灌注。这些方法将用于评估小鼠中的三种SCD候选药物，并在可能的情况下进行人体研究。这些是regadenoson; GMI- 1070;和ATL-801，一种抑制RBC镰状化的临床前A2 BR拮抗剂。经过验证后，我们的目标是将这些技术转移到SCD临床试验中心。我们推测，新的生物标志物，流式细胞仪和CEU的识别，将是更有用的指标的药物有效性比目前使用的临床结果的措施。此外，这些研究将提供有关SCD中触发血管闭塞和组织缺血的细胞和分子事件的新信息。 公共卫生相关性：该项目将使用超声波测量组织血管灌注，并将分析镰状细胞性贫血患者的白色血细胞。这些程序将为我们提供血流和炎症异常的测量方法，用于更好地了解疾病，并帮助评估新治疗方法的有效性。

DESCRIPTION (provided by applicant): In order to identify new biomarkers to assess the status of patients with sickle cell disease (SCD) we have assembled a team of 5 principal investigators with expertise encompassing clinical investigation, immunology, biomedical engineering and microvascular imaging. The overarching hypothesis underlying our proposal is that the severity of tissue injury in SCD is related to the state of inflammation and vascular perfusion. Our goals are to apply minimally invasive techniques for sensitively assessing inflammation and microvascular occlusion to the analysis of mouse and human SCD: 1) flow cytometry of patient blood to measure iNKT cell activation; and 2) contrast enhanced ultrasound (CEU) to measure vascular volume/perfusion in situ in mice and people. These are validated safe techniques borrowed from the fields of immunology and cardiology. We will relate these measures to other disease indices such as clinical status in people and pulmonary function and intravital microscopy in mice. We recently discovered that iNKT cells, which can be inhibited by activation of adenosine A2A receptors (A2ARs), are activated in mice or persons with SCD. We initiated an ongoing clinical investigation (NIH RC2HL101367) facilitated by the availability of the drug regadenoson, an FDA approved A2AR agonist. Another ongoing SCD clinical trial is evaluating GMI-1070, a pan-selectin inhibitor, to reduce leukocyte adhesion to endothelial cells (EC) and vaso-occlusive episodes. To study leukocyte-EC interactions in greater depth we recruited an authority on adhesion molecules and intravital microscopy. In order to study microvascular perfusion in mice and people we recruited an expert in the technique of CEU to measure vascular perfusion in mouse and human studies. Millions of patients have undergone CEU to measure vascular perfusion in heart and other tissues. These methods will be used to assess three SCD drug candidates in mice and when possible, human studies. These are regadenoson; GMI- 1070; and ATL-801, a preclinical A2BR antagonist that inhibits RBC sickling. After they are validated, our goal is to transfer these techniques to SCD clinical trial sites. We hypothesize that the identification of new biomarkers, flow cytometric and CEU, will be more useful indices of drug effectiveness than currently used clinical outcome measures. In addition, these studies will provide new information about the cellular and molecular events that trigger vaso-occlusion and tissue ischemia in SCD. PUBLIC HEALTH RELEVANCE: This project will use ultrasound to measure tissue vascular perfusion, and will analyze white blood cells from patients with sickle cell anemia. These procedures will provide us with measures of abnormalities in blood flow and inflammation that will be used to better understand the disease, and also to help evaluate the effectiveness of new therapeutic approaches.