A Novel Multiparameter Blood Test for Early Detection of Alzheimer's Disease

项目摘要 我们的目标是开发一种基于血液的阿尔茨海默病症状前检测诊断方法 (AD)多参数分析（PreAMP） 目前全球有超过1800万例AD病例，预计病例数将增加近一倍 在接下来的15年里。仅在美国，每年的总经济成本估计接近2000亿美元1。 诊断是复杂、昂贵和耗时的。部分原因是缺乏诊断工具， AD代表了一系列神经退行性疾病，这些疾病具有重叠的症状和蛋白质 病理学由于这些原因，约58%的痴呆症被认为是完全未诊断的，这导致 许多病人得不到充分、及时的护理或治疗2。最近的研究表明， AD患者大脑中常见的聚集蛋白也可以在血液中检测到， 为发展基于血液的诊断提供了希望。然而，到目前为止，不同的研究强调， 单标记物优于多参数方法，对于哪种标记物更优越没有共识3 -9。 因此，多参数生物标志物测定可被证明对于早期诊断癌症是非常有价值的。 不同类型的病人对抗连续性痴呆 绝大多数生物标志物的努力都集中在检测无毒的变异，而不是实际的 参与神经变性的有毒聚集蛋白质种类。最近，我们的项目团队开发了 新的生物淘选技术，使我们能够产生单链抗体可变区抗体， 在本发明的一个实施方案中，提供了与涉及AD和相关疾病的四种关键神经元蛋白的疾病特异性变体结合的单链抗体（scFv）。 痴呆（ADRD）：tau、Aβ、TDP-43和α-syn。我们的scFv仅对脑中发现的变体起反应， 来自ADRD患者但非认知正常对照的血浆样品10 -12。Aβ和TDP-43水平 我们的四种scFv识别的寡聚体在最初诊断为轻度慢性乙型肝炎前数年显著升高， 认知障碍（MCI）9.在疾病进展过程中，我们发现生物标志物谱发生变化，因此我们 基于抗体的诊断也可用于将AD的进展从症状前到晚期进行分期。 阶段，允许对患者进行临床分层，以支持ADRD的实验性治疗决策9。 在这项工作的基础上，该提案旨在开发一种基于血液的AD诊断方法，称为PreAMP。 具体目标是：1）开发一种低容量，多重抗体检测血浆蛋白定量 变体。2)确定用于AD症状前诊断的最佳生物标志物组，3）验证测定 在纵向AD患者样本的盲法回顾性研究中的性能。

Project Summary Our objective is to develop a blood-based diagnostic for Pre-symptomatic detection of Alzheimer's disease (AD) based on a Multiparameter Profiling (PreAMP). Currently there are over 18 million cases of AD worldwide, with the number of cases expected to nearly double over the next 15 years. In the US alone, total economic costs are estimated at nearly $200 billion per year1. Diagnosis is complex, costly and time-consuming. In part because of the lack of diagnostic tools and because AD represents a continuum of neurodegenerative disorders that share overlapping symptoms and protein pathologies. For these reasons, ~58% of dementia is thought to be undiagnosed altogether, which result that many patients do not receive adequate, timely care or treatment2. Recent work has revealed that forms of the aggregated proteins commonly found in the brains of AD patients can also be detected in the blood, showing promise for the development of a blood-based diagnostic. So far, however, different studies have emphasized single markers over a multiparameter approach, with no consensus as to which marker is superior3-9. Therefore, a multiparameter biomarker assay may prove to be extremely valuable for early diagnosis of a diverse range of patients against a continuum of dementias. The vast majority of biomarker efforts have focused on detection of non-toxic variants rather than the actual toxic aggregated protein species involved in neurodegeneration. Recently, our project team has developed novel biopanning technologies that enabled us to generate single chain antibody variable domain antibodies (scFvs) that bind to disease-specific variants of four key neuronal proteins implicated in AD and Related Dementias (ADRD): tau, Aβ, TDP-43, and α-syn. Our scFvs react only to the variants found in brain and plasma samples from ADRD patients but not cognitively normal controls10-12. Levels of Aβ and TDP-43 oligomers recognized by four of our scFvs were significantly elevated years before an initial diagnosis of mild cognitive impairment (MCI)9. During disease progression, we found that biomarker profiles change, so our antibody-based diagnostic could also be used to stage progression of AD from pre-symptomatic through late stage, permitting clinical stratification of patients to support experimental therapy decision-making for ADRD9. Building from this work, this proposal is designed to develop a blood-based diagnostic for AD called PreAMP. The specific aims are to: 1) develop a low-volume, multiplex antibody assay for quantitation of plasma protein variants. 2) determine the optimal biomarker set for pre-symptomatic diagnosis of AD, 3) validate the assay performance in a blinded retrospective study of longitudinal AD patient samples.