MMP9 as a response identification biomarker for doxycycline in Kawasaki disease

摘要 川崎病是发达国家儿童获得性心脏病的主要原因。它 表现为一种急性自限性疾病，伴有发烧和皮肤和粘膜发炎。在……里面 KD，由一种迄今未知的外在因素触发的免疫系统导致多系统血管炎，包括 冠状动脉。即使遵循目前的治疗指南，30%的KD儿童仍将患有冠状动脉 动脉扩张(CAD)。冠心病患者可能面临永久性和潜在的破坏性并发症，如 如冠状动脉血管病变、心肌梗死甚至死亡。目前没有可用的治疗方法或 川崎病患儿冠心病的预防川崎病急性期活化的巨噬细胞和淋巴细胞 冠状动脉壁诱导基质金属蛋白酶9(MMP9)，该酶负责弹性蛋白 降解导致冠心病和动脉瘤。多西环素(一种常见的抗生素和已知的基质金属蛋白酶-9的抑制剂) 显示可减少基质金属蛋白酶-9介导的冠状动脉弹性蛋白破坏并改善冠状动脉预后。 川崎病动物模型。多西环素的应用也被证明降低了主动脉中的基质金属蛋白酶-9的活性。 成人腹主动脉瘤患者的腹壁。我们的初步和公布的数据表明，亲- 基质金属蛋白酶-9是检测川崎病急性期炎症反应的敏感生物标志物 发生，多西环素可阻止KD儿童冠心病的进展。根据这些数据，我们将 检验以下两个假设：1)多西环素在儿童KD Will急性期的应用 降低循环中基质金属蛋白酶-9水平；2)多西环素治疗KD急性期是安全的 能有效预防儿童冠心病的进展和动脉瘤的形成。 具体目标1：表征循环中前-基质金属蛋白酶-9和基质金属蛋白酶-9水平的变化，以响应3- 小儿川崎病急性期口服多西环素一周，通过对多西环素前体的定量研究 治疗3周前后儿童血清中基质金属蛋白酶-9和基质金属蛋白酶-9水平(用酶联免疫吸附试验测定) 多西环素治疗过程中急性KD和NO患儿与对照组的变化比较 多西环素治疗。具体目标2：评估冠状动脉内径对3-羟色胺反应的变化 多西环素在儿童KD急性期的一周口服，通过评估 川崎病急性期4个时间点的冠状动脉超声心动图标准 并与急性川崎病患儿和未用多西环素治疗的对照组进行比较。根据这一结果 试点研究，我们将开发一项前瞻性、多中心、盲法对照临床试验，以评估阿司匹林的疗效。 多西环素在预防冠心病和动脉瘤中的作用如果多西环素被证明是有益的，我们将 建议修改目前接受的KD儿童治疗方案，将多西环素纳入治疗方案 预防冠状动脉动脉瘤和潜在的致命并发症。

ABSTRACT Kawasaki disease (KD) is the leading cause of acquired heart disease in children of the developed world. It presents as an acute self-limiting illness with fever and inflammation of the skin and mucous membranes. In KD, the immune system triggered by a so far unknown extrinsic factor induces multisystem vasculitis including the coronary arteries. Even following current therapeutic guidelines, 30% of children with KD will have coronary artery dilation (CAD). Patients with CAD may face permanent and potentially devastating complications, such as coronary vasculopathy, myocardial infarction and even death. Currently there is no available treatment or prevention of CAD in children with KD. In the acute phase of KD, activated macrophages and lymphocytes in the wall of the coronary arteries induce matrix metalloproteinase 9 (MMP-9) that is responsible for elastin degradation causing CAD and aneurysm. Doxycycline (a common antibiotic and a known inhibitor of MMP-9) was shown to decrease MMP-9-mediated coronary elastin breakdown and improve coronary outcome in animal models of KD. Doxycycline administration was also demonstrated to reduce MMP-9 activity in the aortic wall of adults with abdominal aortic aneurysm. Our preliminary and published data demonstrates that pro- MMP-9 is a sensitive biomarker to detect inflammation in children during the acute phase of KD when CAD occurs, and doxycycline may prevent the progression of CAD in children with KD. Based on these data, we will test the following two hypotheses: 1) doxycycline administration in children during the acute phase of KD will decrease the circulating level of MMP-9; and 2) doxycycline treatment during the acute phase of KD is safe and effective to prevent the progression of CAD and aneurysm formation in children. Specific aim 1: To characterize the change in circulating pro-MMP-9 and MMP-9 levels in response to a 3- week oral administration of doxycycline in children during the acute phase of KD, by the quantification of pro- MMP-9 and MMP-9 levels (measured by ELISA) in serum samples of children before and after a 3-week course of doxycycline treatment, and comparing the changes to controls of children with acute KD and no doxycycline treatment. Specific aim 2: To assess the change in coronary artery diameter in response to a 3- week oral administration of doxycycline in children during the acute phase of KD, by assessing the size of coronary arteries using established echocardiographic standards during 4 time-points in the acute phase of KD and comparing to controls of children with acute KD and no doxycycline treatment. Based on the results of this pilot study, we will develop a prospective, multi-center, blinded controlled clinical trial to assess the efficacy of doxycycline treatment in the prevention of CAD and aneurysm. If doxycycline proves to be beneficial, we will propose a change of the currently accepted treatment protocol of children with KD to include doxycycline for the prevention of coronary artery aneurysms and potentially fatal complications.