Age-dependent diagnostic and correlational architecture of multiplex plasma biomarkers in Alzheimer’s disease: a cross-ethnic, cross-platform validation study

Relative importance of blood-based biomarkers for Alzheimer’s disease-specific neurodegeneration and cognitive decline

A stratified approach based on amyloid status is essential for the optimal application of blood-based biomarkers in monitoring disease progression and evaluating therapeutic efficacy in future clinical trials and precision medicine.

Blood-based multimodal biomarker models for differentiating early-onset Alzheimer’s disease from frontotemporal dementia: a longitudinal study of early-onset dementia and family members (LEAF) study

Cross-Sectional and Longitudinal Diagnostic Performance of Plasma p-tau217 and p-tau217/Aβ42 in Alzheimer's Disease.

OBJECTIVE Recent studies suggest that combining plasma phosphorylated tau (p-tau) with β-amyloid (Aβ) may improve diagnosis accuracy for Alzheimer's disease (AD). However, the cross-sectional and longitudinal concordance of these markers with Aβ positron emission tomography (PET) positivity remains incompletely understood. This study aimed to evaluate the diagnostic performance of plasma p-tau, alone and in combination with plasma Aβ, in AD. METHODS We included 326 participants from the Alzheimer's Disease Neuroimaging Initiative and 357 Chinese older adults from the Greater-Bay-Area Healthy Aging Brain Study who underwent Aβ-PET imaging. Longitudinal data were available for 285 Alzheimer's Disease Neuroimaging Initiative participants. Plasma p-tau181, p-tau217, Aβ42, and Aβ40 were measured on different analytical platforms. Diagnostic performance for Aβ-PET positivity was assessed using a two-cutoff approach. RESULTS Combining plasma p-tau with Aβ42 or the Aβ42/40 ratio reduced the intermediate zone. Notably, p-tau217/Aβ42 showed stronger agreement with Aβ-PET positivity than p-tau217 alone. Among individuals classified as p-tau217/Aβ42 positive but p-tau217 intermediate, 57.1 to 83.3% were Aβ-PET positive. Longitudinally, most Stable Positive (88.0-96.1%) and Stable Negative (89.4-90.9%) cases defined by p-tau217 or p-tau217/Aβ42 were Aβ-PET positive and Aβ-PET negative, respectively. Critically, 69.7 to 75.8% of Non-positive to Positive cases defined by p-tau217/Aβ42 were Aβ-PET positive. INTERPRETATION These findings provide novel insights into the cross-sectional and longitudinal diagnostic performance of plasma p-tau217/Aβ42 in AD. To be specific, plasma p-tau217/Aβ42 can reduce the intermediate zone and improve agreement with Aβ-PET positivity, and longitudinal p-tau217/Aβ42 monitoring is particularly informative for identifying Aβ-PET-positive patients who were p-tau217/Aβ42 negative or intermediate at baseline and were misclassified as low risk of AD. ANN NEUROL 2026.

Predictive value of plasma p-tau217 for Alzheimer’s dementia compared to other blood-based biomarkers

Phosphorylated-tau (p-tau217) is a promising blood-based biomarker for Alzheimer’s dementia (AD) in clinical settings. However, research from prospective cohort studies is sparse. We measured plasma p-tau217 levels in baseline blood samples of 779 participants in a population-based cohort of older adults followed over 17 years. Associations with AD were assessed and compared to those with previous measurements of p-tau181, neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP). Comparisons to the amyloid beta (Aβ) misfolding biomarker were performed in a subgroup analysis. P-tau217, NfL and GFAP showed strong associations with AD risk, especially within the first 9 years of follow-up, outperforming p-tau181. Over the later years of follow-up, the predictive accuracy of p-tau217 was significantly reduced. In contrast, the Aβ misfolding biomarker demonstrated superior performance especially as a preclinical indicator of the risk of AD many years before diagnosis. The combination of p-tau217 with NfL, GFAP, basic demographic and genetic information, as well as the misfolding biomarker yielded an AUC 0.86 for AD diagnoses over the entire 17-year follow-up period. P-tau217 is a promising blood-based biomarker for Alzheimer’s dementia (AD) in the clinical stage. In this prospective cohort study, it showed better performance in the prodromal than in the preclinical stage up to 17 years before diagnosis. In a subgroup analysis, the Aß misfolding biomarker showed higher discriminative ability in the preclinical stage compared to p-tau217. A prediction model including p-tau217, NfL, GFAP, Aß misfolding as well as basic demographic and genetic information reached an AUC of 0.86 for AD over the entire follow-up period. In a subgroup analysis, the Aß misfolding biomarker showed higher discriminative ability in the preclinical stage compared to p-tau217. A prediction model including p-tau217, NfL, GFAP, Aß misfolding as well as basic demographic and genetic information reached an AUC of 0.86 for AD over the entire follow-up period. P-tau217 is a promising blood-based biomarker for Alzheimer’s dementia (AD) in the clinical stage. In this prospective cohort study, it showed better performance in the prodromal than in the preclinical stage up to 17 years before diagnosis.

Serum p-Tau217 and apolipoprotein E as potential biomarkers for Alzheimer's disease severity: a case-control study

Increased serum p-tau217 and decreased ApoE levels were significantly associated with greater AD severity, suggesting that both biomarkers may serve as complementary noninvasive indicators of disease severity in Alzheimer’s disease.

Diagnostic Performance of the AlzoSure Predict Assay and Its Association With Alzheimer's Disease Biomarkers and Imaging Findings

This work aimed to evaluate the association between U‐p53AZ with established cerebrospinal fluid (CSF) and neuroimaging measures, and to determine its diagnostic performance in distinguishing cognitively normal individuals from those with mild cognitive impairment (MCI).