Abstract

Background:

Early and accurate detection and staging is critical to managing Alzheimer’s disease (AD) and supporting clinical trials. Cerebrospinal fluid (CSF) biomarkers for amyloid-β peptides, tau species, and various neurodegenerative and inflammatory analytes are leading the way in this regard, yet there is room for improved sensitivity and specificity. In particular tau is known to be present in many different fragments, conformations, and post-translationally modified forms. While the exact tau species that might best reflect AD pathology is unknown, a growing body of evidence suggests that forms with high levels of phosphorylation in the mid-region may be especially enriched in AD.

Objective:

Develop an assay for measuring p217tau in CSF.

Methods:

Here we describe the development and validation of a novel sELISA for measuring CSF tau species containing phosphorylation at threonines 212 & 217, aka p217 + tau, using the PT3 antibody.

Results:

While the analyte is present at extremely low levels the assay is sufficiently sensitive and specific to quantitate p217 + tau with excellent precision, accuracy, and dilution linearity, allowing good differentiation between diagnostic subgroups. The p217 + tau measurements appear to track AD pathology better than the commonly used p181tau epitope, suggesting superior diagnostic and staging performance. Finally, the assay can also be configured to differentiate antibody-bound versus antibody-free tau, and therefore can be used to measure target engagement by p217 + tau-targeting immunotherapeutics.

Conclusion:

The assay for measuring p217 + tau described here is highly sensitive, accurate, precise, dilution linear, and shows good potential for identifying and staging AD.

中文翻译：

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用于测量脑脊液中 p217 + tau 的高灵敏度测定的开发和验证。

摘要

背景：

早期准确的检测和分期对于管理阿尔茨海默病 (AD) 和支持临床试验至关重要。β 淀粉样肽、tau 物质和各种神经退行性和炎症分析物的脑脊液 (CSF) 生物标志物在这方面处于领先地位，但仍有提高灵敏度和特异性的空间。特别是已知 tau 以许多不同的片段、构象和翻译后修饰的形式存在。虽然可能最能反映 AD 病理的确切 tau 种类尚不清楚，但越来越多的证据表明，在中间区域具有高水平磷酸化的形式可能在 AD 中特别丰富。

客观的：

开发一种测定 CSF 中 p217tau 的方法。

方法：

在这里，我们描述了一种新型 sELISA 的开发和验证，用于使用 PT3 抗体测量 CSF tau 物种，其中包含苏氨酸 212 和 217 磷酸化，又名 p217 + tau。

结果：

虽然分析物的含量极低，但该测定具有足够的灵敏度和特异性，可以以出色的精密度、准确度和稀释线性对 p217 + tau 进行定量，从而可以很好地区分诊断亚组。p217 + tau 测量似乎比常用的 p181tau 表位更好地跟踪 AD 病理，表明具有优越的诊断和分期性能。最后，测定还可以被配置为区分抗体结合与抗体免费tau蛋白，因此可用于测量由P217 + tau蛋白靶向免疫治疗靶接合。

结论：

此处描述的测量 p217 + tau 的检测具有高度灵敏、准确、精确、稀释线性，并且显示出识别和分期 AD 的良好潜力。