Biomarkers of Inflammation and Vaso-occlusion in Sickle Cell Disease

描述（由申请人提供）：为了确定新的生物标志物来评估镰状细胞病（SCD）患者的状态，我们组建了一个由5名主要研究人员组成的团队，他们的专业知识包括临床调查、免疫学、生物医学工程和微血管成像。我们提出的首要假设是，SCD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评估炎症和微血管闭塞的小鼠和人SCD分析：1)患者血液流式细胞术测量iNKT细胞活化；2)对比增强超声（CEU）原位测量小鼠和人的血管体积/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。我们将把这些措施与其他疾病指标联系起来，如人的临床状况、肺功能和小鼠的活体显微镜检查。我们最近发现，可以通过激活腺苷A2A受体（A2ARs）来抑制的iNKT细胞在小鼠或SCD患者中被激活。我们启动了一项正在进行的临床研究（NIH RC2HL101367），药物regadenoson是FDA批准的A2AR激动剂。另一项正在进行的SCD临床试验是评估GMI-1070，一种泛选择素抑制剂，以减少白细胞粘附内皮细胞（EC）和血管闭塞发作。为了更深入地研究白细胞- ec相互作用，我们聘请了粘附分子和活体显微镜方面的权威。为了研究小鼠和人的微血管灌注，我们聘请了CEU技术的专家来测量小鼠和人的血管灌注。数以百万计的患者接受了CEU来测量心脏和其他组织的血管灌注。这些方法将用于在小鼠中评估三种SCD候选药物，并在可能的情况下进行人体研究。这些是反腺苷子；GMI - 1070;ATL-801是一种临床前A2BR拮抗剂，可抑制红细胞镰状细胞。经过验证后，我们的目标是将这些技术转移到SCD临床试验地点。我们假设鉴定新的生物标志物，流式细胞术和CEU，将是比目前使用的临床结果测量更有用的药物有效性指标。此外，这些研究将为SCD中引发血管闭塞和组织缺血的细胞和分子事件提供新的信息。

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.