INTRODUCTION: Plasma phosphorylated tau (p‐tau) biomarkers have improved Alzheimer's disease (AD) diagnosis, but data from diverse Asian populations are limited. This study evaluated plasma p‐tau217 and p‐tau181 levels in Korean and Taiwanese populations. METHODS: All participants ( n = 270) underwent amyloid positron emission tomography (PET) and blood tests. Plasma p‐tau model‐derived probabilities of amyloid PET positivity (amyloid beta [Aβ]+) classified participants into low‐, intermediate‐, or high‐risk groups. RESULTS: In both cohorts, plasma p‐tau217 outperformed p‐tau181, especially in cognitively unimpaired participants (area under the curve = 0.921 [p‐tau217] vs. 0.769 [p‐tau181], P _difference  = 0.022). Including apolipoprotein E status and glial fibrillary acidic protein improved model fit. The negative predictive value of the low‐risk group and positive predictive value of the high‐risk group were 97.5% and 86.0%, respectively. DISCUSSION: Plasma p‐tau217 and p‐tau181 effectively predict Aβ+ among culturally different Asian populations. P‐tau217 performed better, especially in the early stages of AD. Plasma p‐tau217–based models reduced intermediate‐risk classifications, suggesting fewer amyloid PET scans needed to confirm the diagnosis. Highlights: The efficacy of plasma phosphorylated tau (p‐tau)217 and p‐tau181 was analyzed in two Asian populations. Plasma p‐tau217 performs better in predicting amyloid positron emission tomography positivity, especially in cognitively unimpaired subjects. Adding apolipoprotein E and glial fibrillary acidic protein to p‐tau improved model accuracy. The models from each cohort were confirmed in the other cohort. Plasma p‐tau–based risk stratification may reduce the need for confirmatory tests.

Kwon HS, et al. Dement Neurocogn Disord. 2023 Jul;22(3):109-111. https://doi.org/10.12779/dnd.2023.22.3.109

Kwon HS, et al. J Clin Neurol. 2020 Oct;16(4):605-611. https://doi.org/10.3988/jcn.2020.16.4.605

Kwon HS, et al. J Clin Neurol. 2022 Jan;18(1):24-32. https://doi.org/10.3988/jcn.2022.18.1.24