University of Pennsylvania, Philadelphia, Pennsylvania, USA.
University of Milan-Bicocca Faculty of Medicine and Surgery, Universita degli Studi di Milano-Bicocca Dipartimento di Medicina e Chirurgia, Milan, Italy.
Alzheimers Dement. 2022 Jun;18(6):1235-1247. doi: 10.1002/alz.12456. Epub 2021 Sep 13.
Longitudinal positron emission tomography (PET) studies of tau accumulation in Alzheimer's disease (AD) have noted reduced increases or frank decreases in tau signal. We investigated how such reductions related to analytical confounds and disease progression markers in atypical AD.
We assessed regional and interindividual variation in longitudinal change on F-flortaucipir PET imaging in 24 amyloid beta (Aβ)+ patients with atypical, early-onset amnestic or non-amnestic AD plus 62 Aβ- and 132 Aβ+ Alzheimer's Disease Neuroimaging Initiative (ADNI) participants.
In atypical AD, F-flortaucipir uptake slowed or declined over time in areas with high baseline signal and older, more impaired individuals. ADNI participants had reduced longitudinal change in early Braak stage regions relative to late-stage areas.
Results suggested radioligand uptake plateaus or declines in advanced neurodegeneration. Further research should investigate whether results generalize to other radioligands and whether they relate to changes of the radioligand binding site structure or accessibility.
对阿尔茨海默病（AD）中 tau 积累的纵向正电子发射断层扫描（PET）研究表明，tau 信号的增加减少或明显减少。我们研究了这种减少与不典型 AD 中的分析混杂因素和疾病进展标志物的关系。
我们评估了 24 名具有不典型、早发性遗忘或非遗忘 AD 的淀粉样蛋白 β（Aβ）+患者以及 62 名 Aβ-和 132 名 Aβ+阿尔茨海默病神经影像学倡议（ADNI）参与者的 F-氟替卡滨 PET 成像中纵向变化的区域和个体间变异性。
在不典型 AD 中，基线信号较高和年龄较大、认知障碍程度较高的个体中， F-氟替卡滨摄取随时间推移而减缓或下降。ADNI 参与者在早期 Braak 阶段区域的纵向变化减少，而在晚期阶段区域的纵向变化减少。
结果表明放射性配体摄取在晚期神经退行性变中达到平台或下降。进一步的研究应该调查这些结果是否适用于其他放射性配体，以及它们是否与放射性配体结合位点结构或可及性的变化有关。
