Background:The recent developed PET ligands for amyloid-β (Aβ) and tau allow these two neuropathological hallmarks of Alzheimer’s disease (AD) to be mapped and quantified in vivo and to be examined in relation to cognition. Objective:To assess the associations among Aβ, tau, and cognition in non-demented subjects. Methods:Three hundred eighty-nine elderly participants without dementia from the Alzheimer’s Disease Neuroimaging Initiative underwent tau and amyloid PET scans. Cross-sectional comparisons and longitudinal analyses were used to evaluate the relationship between Aβ and tau accumulation. The correlations between biomarkers of both pathologies and performance in memory and executive function were measured. Results:Increased amyloid-PET retention was associated with greater tau-PET retention in widespread cortices. We observed a significant tau increase in the temporal composite regions of interest over 24 months in Aβ+ but not Aβ– subjects. Finally, tau-PET retention but not amyloid-PET retention significantly explained the variance in memory and executive function. Higher level of tau was associated with greater longitudinal memory decline. Conclusion:These findings suggested PET-detectable Aβ plaque pathology may be a necessary antecedent for tau-PET signal elevation. Greater tau-PET retention may demonstrate poorer cognition and predict prospective memory decline in non-demented AD subjects.

中文翻译：

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升高的 Tau PET 信号取决于异常淀粉样蛋白水平，并与非痴呆老年人的认知障碍相关

背景：最近开发的 β 淀粉样蛋白 (Aβ) 和 tau 的 PET 配体允许在体内绘制和量化阿尔茨海默病 (AD) 的这两个神经病理学标志，并在认知方面进行检查。目的：评估非痴呆受试者 Aβ、tau 和认知之间的关联。方法：来自阿尔茨海默病神经影像学计划的 389 名没有痴呆的老年参与者接受了 tau 和淀粉样蛋白 PET 扫描。横断面比较和纵向分析用于评估 Aβ 与 tau 积累之间的关系。测量了病理学生物标志物与记忆和执行功能表现之间的相关性。结果：淀粉样蛋白-PET 保留增加与广泛皮质中更大的 tau-PET 保留相关。我们观察到 Aβ+ 受试者在 24 个月内感兴趣的时间复合区域的 tau 显着增加，但 Aβ-受试者没有。最后，tau-PET 保留而不是淀粉样蛋白-PET 保留显着解释了记忆和执行功能的差异。较高水平的 tau 与更大的纵向记忆衰退有关。结论：这些发现表明 PET 可检测的 Aβ 斑块病理可能是 tau-PET 信号升高的必要前提。较大的 tau-PET 保留可能表明认知能力较差，并预测非痴呆 AD 受试者的预期记忆力下降。较高水平的 tau 与更大的纵向记忆衰退有关。结论：这些发现表明 PET 可检测的 Aβ 斑块病理可能是 tau-PET 信号升高的必要前提。较大的 tau-PET 保留可能表明认知能力较差，并预测非痴呆 AD 受试者的预期记忆力下降。较高水平的 tau 与更大的纵向记忆衰退有关。结论：这些发现表明 PET 可检测的 Aβ 斑块病理可能是 tau-PET 信号升高的必要前提。较大的 tau-PET 保留可能表明认知能力较差，并预测非痴呆 AD 受试者的预期记忆力下降。