Development of a Molecular Diagnostic to Identify Dangerous Intracranial Aneurysms

项目摘要 颅内动脉瘤(IA)破裂是非外伤性蛛网膜下腔出血的主要原因。 具有高死亡率(50%)和永久性残疾(幸存者50%)的灾难性事件。 当发现未破裂的IA时，临床医生面临着是否应该进行治疗的艰难决定。 由于破裂率低(每年破裂率约为0.5-1%)，而介入治疗的并发症风险 重要的是，至关重要的是对破裂风险进行分层，以便危险的IAS立即得到治疗，同时减少 可以定期监测危险的情况。在临床实践中，动脉瘤的大小一直是主要的标准。 用于治疗，但并不总是可靠的。最近，其他临床指标，如分期(人口， 高血压、年龄、IA的大小、较早的蛛网膜下腔出血和IA的部位)评分，使用IA 为了更好地对风险进行分层，已经制定和验证了患者特征和患者人口统计学特征。 然而，与IA大小一样，此类风险度量只有在患者接收到数字后才能准确评估 减影血管造影术(DSA)，这是有创的，昂贵(每次扫描5,000-8,500美元)，对暂时性或 永久性并发症。此外，这些指标缺乏关于潜在生物差异的信息 可以更好地区分高风险和低风险病例的国际会计准则。危险的IAS的血液诊断将会 实现更明智的IA管理，并可提供一种低成本、非侵入性的方式来监控患者 在警觉等待期间或治疗后(在随访成像之间)。 在过去的几年里，神经血管诊断一直在开发一种基于血液的IA诊断 名为AneuScreenTM。在发育过程中，我们发现某些基因的表达差异也是分层的 IA病例按IA大小以“剂量依赖”的方式显示，这导致我们假设患有高危IA的患者 在他们的血液中有可区分的基因表达模式。在一个成功完成的第一期SBIR项目中， 我们使用了中等大小的IA患者的全血转录本来开发和测试机器 高危动脉瘤病例的学习分类器(按阶段评分划分)。这款车进行了88%的测试 准确性、78%的敏感性和95%的特异性。尽管有这些令人兴奋的结果，但还需要进一步的工作来翻译 将该生物标志物转化为诊断性检测，这是本次SBIR二期项目的重点。在目标1中，我们将验证 IA内的基因在先前收集的血液样本的大型数据集中存在风险生物标记物，这些样本将被 进行RNA测序。在目标2中，我们将标准化对已建立的 利用定量聚合酶链式反应和毛细管电泳法进行表达读出的临床平台。这些模型将被重新- 经过培训以使用这种新的输出数据类型表现良好。最后，在目标3中，我们将测试开发的检测方法，该方法 我们称之为AneuScreenTM+(或AneuScreenTM Plus)，在400名IA患者和200名IA患者的前瞻性队列中 控制。成功完成此第二阶段将决定我们的原型IA诊断是否可以扩展其 除了识别IA之外，还可以通过对IA风险进行分层来提高其能力和价值。

Project Summary Intracranial aneurysm (IA) rupture is the primary cause of non-traumatic subarachnoid hemorrhage, a catastrophic event that carries high rates of mortality (>50%) and permanent disability (>50% among survivors). When an unruptured IA is discovered, clinicians face the difficult decision of whether or not it should be treated. Since rupture rates are low (risk of rupture ~ 0.5-1% per year), while complication risks of intervention can be significant, it is critical to stratify rupture risk such that the dangerous IAs are treated right away while less dangerous ones can be periodically monitored. In clinical practice, aneurysm size has been the principal criterion for treatment, but it is not always reliable. Recently, other clinical metrics, such as the PHASES (Population, Hypertension, Age, Size of IA, Earlier subarachnoid hemorrhage, and Site of IA) score, which use IA characteristics and patient demographics, have been developed and validated in attempts to better stratify risk. However, like IA size, such risk metrics can only be accurately assessed after the patient has received digital subtraction angiography (DSA), which is invasive, expensive ($5,000-8,500 per scan), and risky for transient or permanent complications. Furthermore, these metrics lack information about biological differences underlying IAs that may better discriminate high- vs low-risk cases. A blood-based diagnostic of dangerous IAs would enable more informed IA management and could offer a low-cost, non-invasive way to monitor patients during watchful waiting or after treatment (between follow-up imaging). Over the past several years, Neurovascular Diagnostics has been developing a blood-based IA diagnostic called AneuScreenTM. During development, we found that expression differences of certain genes also stratified IA cases by IA size in a “dose-dependent” manner, leading us to hypothesize that patients with high-risk IAs have distinguishable gene expression patterns in their blood. In a successfully completed Phase I SBIR project, we used whole blood transcriptomes from a modestly-sized dataset of IA patients to develop and test machine learning classifiers of high-risk aneurysm cases (delineated by PHASES score). This model had 88% testing accuracy, 78% sensitivity, and 95% specificity. Despite these exciting results, further work is needed to translate this biomarker into a diagnostic test, which is the focus of this Phase II SBIR project. In Aim 1, we will validate the genes within the IA risk biomarker in a large dataset of previously-collected blood samples that will be subjected to RNA sequencing. In Aim 2, we will standardize the assessment of the biomarker on an established clinical platform that utilizes qPCR and capillary electrophoresis for expression readout. The models will be re- trained to perform well using this new output data-type. Lastly, in Aim 3, we will test the developed assay, which we call AneuScreenTM+(or AneuScreenTM Plus), in a prospective cohort of n=400 patients with IA and n=200 controls. Successful completion of this Phase II will determine if our prototype IA diagnostic can expand its capabilities and increase its value by stratifying IA risk, in addition to identifying IA.