Prospective evaluation of plasma phosphorylated tau in a real‐life memory clinic in Thailand.

Introduction: Despite the substantial accuracy of plasma p‐tau in diagnosing Alzheimer's disease (AD) in research cohorts, data on real‐life memory clinic patients are lacking. Methods: Memory clinic patients at their early symptomatic stages were prospectively enrolled to undergo routine clinical assessment, plasma p‐tau181 quantification (Simoa), amyloid and tau‐positron emission tomography (PET). The diagnostic performance of plasma p‐tau181, neurocognitive specialists, and regional tau‐PET were compared head‐to‐head using amyloid‐PET as the reference standard. Results: Plasma p‐tau181 has the area under the curve (AUC), sensitivity, specificity, and accuracy of 0.84 (95% confidence interval [CI] 0.73–0.94), 0.80 (95% CI 0.64–0.90), 0.75 (95% CI 0.51–0.90), and 0.78 (95% CI 0.65–0.88) for detecting amyloid‐PET positivity in early symptomatic patients, respectively. The AUC of clinical diagnosis and tau‐PET were 0.70 (95% CI 0.56–0.85) and 0.88 (95% CI 0.79–0.97), respectively. Discussion: Plasma p‐tau181 also performed well in real‐life memory clinic settings and its role in clinical practice is supported. [ABSTRACT FROM AUTHOR]