1Florida Alzheimer's Disease Research Center (ADRC), Miami, FL, USA.
Center for Cognitive Neuroscience and Aging (CNSA), Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA.
J Alzheimers Dis. 2024;101(4):1195-1204. doi: 10.3233/JAD-240164.
Semantic intrusion errors (SIEs) are both sensitive and specific to PET amyloid-β (Aβ) burden in older adults with amnestic mild cognitive impairment (aMCI).
Plasma Aβ biomarkers including the Aβ42/40 ratio using mass spectrometry are expected to become increasingly valuable in clinical settings. Plasma biomarkers are more clinically informative if linked to cognitive deficits that are salient to Alzheimer's disease (AD).
This study included 119 older adults enrolled in the 1Florida Alzheimer's Disease Research Center (ADRC), 45 aMCI participants scored below the established Aβ42/40 ratio cut-off of 0.160 using the Quest AD-Detect™ assay indicating Aβ positivity (Aβ+), while 50 aMCI participants scored above this cut-off indicating Aβ negative status (Aβ-). Additionally, 24 cognitively unimpaired (CU) persons scored above the cut-off of 0.160 (Aβ-).
The aMCI plasma Aβ+ group evidenced the greatest percentage of SIEs, followed by the aMCI Aβ-. The CU Aβ- group exhibited the lowest percentage of SIEs. After adjustment for global cognitive impairment, aMCI plasma Aβ+ continued to demonstrate greater SIEs on tests tapping the failure to recover from proactive semantic interference (frPSI) as compared to the aMCI Aβ-group. Using pre-established cut-offs for frPSI impairment, 8.3% of CU Aβ- participants evidenced deficits, compared to 37.8% of aMCI Aβ-, and 74.0% of aMCI Aβ+.
SIEs reflecting frPSI were associated with aMCI Aβ+ status based on the Aβ42/40 ratio. Results suggest the importance of SIEs as salient cognitive markers that map onto underlying AD pathology in the blood.
语义侵入错误（SIE）对有遗忘型轻度认知障碍（aMCI）的老年人大脑淀粉样蛋白（Aβ）负担具有高度敏感性和特异性。
使用质谱法测定的 Aβ42/40 比值等血浆 Aβ 生物标志物有望在临床环境中变得越来越有价值。如果与对阿尔茨海默病（AD）有重要意义的认知缺陷相关联，那么血浆生物标志物将更具临床意义。
本研究纳入了 119 名参加佛罗里达 AD 研究中心（ADRC）的老年人，其中 45 名 aMCI 患者使用 Quest AD-Detect™ 检测试剂盒，其 Aβ42/40 比值低于 0.160 的既定截值，表明 Aβ 阳性（Aβ+），而 50 名 aMCI 患者的 Aβ42/40 比值高于该截值，表明 Aβ 阴性状态（Aβ-）。此外，24 名认知正常（CU）者的 Aβ42/40 比值高于 0.160（Aβ-）。
aMCI 血浆 Aβ+组的 SIE 百分比最大，其次是 aMCI Aβ-组。CU Aβ-组的 SIE 百分比最低。在调整了整体认知障碍后，与 aMCI Aβ-组相比，aMCI 血浆 Aβ+组在测试中表现出更大的 SIE，这些测试反映了无法从主动语义干扰中恢复（frPSI）。使用预先确定的 frPSI 损伤的截止值，8.3%的 CU Aβ-参与者表现出缺陷，而 aMCI Aβ-组为 37.8%，aMCI Aβ+组为 74.0%。
基于 Aβ42/40 比值，反映 frPSI 的 SIE 与 aMCI Aβ+状态相关。结果表明，SIE 作为重要的认知标志物，在血液中与 AD 病理相关。
