Plasma p-tau217 Can Reliably Detect Preclinical Alzheimer Disease

THURSDAY, Dec. 11, 2025 (HealthDay News) — Plasma phosphorylated tau 217 (p-tau217) can reliably detect Alzheimer disease (AD) pathology in the preclinical stage, according to a meta-analysis published online Dec. 1 in JAMA Neurology.

Michael Malek-Ahmadi, Ph.D., from the University of Arizona College of Medicine-Phoenix, and colleagues conducted a systematic literature review to identify published studies that compared amyloid-positive and amyloid-negative older adults without cognitive impairment. A meta-analysis was conducted to assess the standardized effect size of mean differences and classification accuracy of p-tau217.

Based on 18 studies (7,834 participants), the researchers found that a large effect size was observed for p-tau217 (Hedges g = 1.50). Values for p-tau217 also showed high accuracy for identifying amyloid-positive individuals without cognitive impairment (pooled area under the curve, 0.87).

“These findings demonstrate that plasma p-tau217 can reliably detect AD pathology in the preclinical stage,” the authors write. “These findings support the clinical utility of plasma p-tau217 as a scalable, minimally invasive tool for early identification of AD, particularly in settings where timely intervention with disease-modifying therapies may offer the greatest benefit in slowing or preventing disease progression.”

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