Can Plasma p-Tau217 Accurately Identify Individuals in Preclinical AD Stage?

Background: Use of blood-based biomarkers (BBMs) for detection of symptomatic Alzheimer disease (AD) has documented utility. Objective: To ascertain the practicality of measurement of plasma phosphorylated tau217 (p-tau217) for detecting AD pathology in cognitively unimpaired older adults. Design: Meta-analysis of randomized clinical trials and observational studies. Methods: This meta-analysis reviewed 17 studies including 7834 individuals with p-tau217 data who were cognitively normal and who were amyloid-positive (n=2533) or amyloid-negative (n=5301) based on cerebrospinal fluid (CSF) assays or amyloid PET. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline was used for this meta-analysis of studies published from 2021 to 2025. Mean age was 68.2 years for amyloid-negative individuals, and 70.9 years for those who were amyloid-positive. Results: Effect size indicates the difference between 2 groups in standard deviation units. For this meta-analysis, t more...