Clinical utility of LUMIPULSE plasma p-tau217 to identify amyloid positivity among candidates for amyloid-targeting treatments in a real-world cohort.

INTRODUCTION: Increasing clinical use of amyloid-targeting treatments (ATTs) requires accessible biomarkers for Alzheimer's disease (AD). Although the utility of plasma phosphorylated tau 217 (p-tau217) is well established in research cohorts and its use for identifying amyloid positivity among ATT candidates is expanding into clinical practice, real-world evidence of its performance is lacking. METHODS: We evaluated the utility of LUMIPULSE plasma p-tau217 in a real-world cohort of 99 patients screened for ATT eligibility. RESULTS: Amyloid positivity was confirmed in 82 (82.8%) patients. Plasma p-tau217 predicted amyloid status, with an area under the curve of 0.93. With a cutpoint (0.1795 pg/mL) based on the Youden index, this approach achieved 95.1% sensitivity, 94.1% specificity, 98.7% positive predictive value, and 80.0% negative predictive value (NPV). Higher external thresholds led to a lower NPV, demonstrating that cut points must be optimized for clinical stages. DISCUSSION: These findings provide real-world evidence supporting the clinical utility of p-tau217 for ATT candidates.