Comparison of two plasma p-tau217 assays to detect and monitor Alzheimer's pathology.

BACKGROUND: Blood-based biomarkers of Alzheimer's disease (AD) have become increasingly important as scalable tools for diagnosis and determining clinical trial eligibility. P-tau217 is the most promising due to its excellent sensitivity and specificity for AD-related pathological changes. METHODS: We compared the performance of two commercially available plasma p-tau217 assays (ALZpath p-tau217 and Janssen p-tau217+) in 294 individuals cross-sectionally. Correlations with amyloid PET and tau PET were assessed, and Receiver Operating Characteristic (ROC) analyses evaluated both p-tau217 assays for identifying AD pathology. FINDINGS: Both plasma p-tau217 assays were strongly associated with amyloid and tau PET. Furthermore, both plasma p-tau217 assays identified individuals with AD vs other neurodegenerative diseases (ALZpath AUC = 0.95; Janssen AUC = 0.96). Additionally, plasma p-tau217 concentrations rose with AD severity and their annual changes correlated with tau PET annual change. INTERPRETATION: Both p-tau217 assays had excellent diagnostic performance for AD. Our study supports the future clinical use of commercially-available assays for p-tau217. FUNDING: This research is supported by the Weston Brain Institute, Canadian Institutes of Health Research (CIHR), Canadian Consortium on Neurodegeneration in Aging, the Alzheimer's Association, Brain Canada Foundation, the Fonds de Recherche du Québec - Santé and the Colin J. Adair Charitable Foundation.

Functional Cognitive Disorder Presents High Frequency and Distinct Clinical Profile in Patients With Low Education.

Introduction: Functional Cognitive Disorder (FCD) is a non-degenerative, common cause of memory complaint in patients with high educational levels. FCD has been insufficiently described in individuals with low education. Here, we investigated the frequency of FCD among individuals with low education. Methods: We analyzed retrospectively all new referrals from primary care to a tertiary memory clinic from 2014 to 2021. Final diagnosis, diagnostic work-up, clinical and cognitive testing data were compared between FCD and other diagnoses, grouped as Neurodegenerative Disorders (NDD). A regression model was used to assess the effect of education on the diagnosis. Data is shown in Mean [SD]. Results: A total of 516 individuals (70.76 [10.3] years) with low educational attainment (4.5 [3.94] years) were divided into FCD (146, 28.3%) and NDD. Compared with NDD, FCD patients showed lower age at presentation (66.2 [9.4] vs. 72.6 [10.2], p < 0.001), higher Mini-Mental State Examination (MMSE) scores (22.4 [6.2] vs. 14.7 [7.8], p < 0.001) and Geriatric Depression Scale (GDS) scores (7.4 [5.4] vs. 5.3 [3.7], p = 0.0001). Discussion: Surprisingly, FCD was the most frequent diagnosis in a low educational setting. However, education was not associated with FCD. Individuals presenting FCD showed a distinct clinical profile, including younger age and higher depressive scores. Strategies to identify FCD in primary care settings may benefit both patients and healthcare systems.