Clinical utility of plasma p-tau217 in identifying abnormal brain amyloid burden in an Asian cohort with high prevalence of concomitant cerebrovascular disease

INTRODUCTION

Using an Asian cohort with high prevalence of concomitant cerebrovascular disease (CeVD), we evaluated the performance of a plasma immunoassay for tau phosphorylated at threonine 217 (p-tau217) in detecting amyloid beta positivity (Aβ+) on positron emission tomography and cognitive decline, based on a three-range reference, which stratified patients into low-, intermediate-, and high-risk groups for Aβ+.

METHODS

Brain amyloid status (Aβ– [n = 142] vs Aβ+ [n = 73]) on amyloid PET scans was assessed along with the plasma ALZpath p-tau217 assay to derive three-range reference points for PET Aβ+ based on 90% sensitivity (lower threshold) and 90% specificity (upper threshold).

RESULTS

Plasma p-tau217 (area under the curve [AUC] = 0.923) outperformed routine clinical assessments (AUC = 0.760–0.819; p ≤ 0.003) and other plasma biomarkers (AUC = 0.817–0.834; p < 0.001). The high-risk group showed significantly higher rates of cognitive decline than the low-risk group.

DISCUSSION

Risk stratification for PET Aβ+ based on a plasma p-tau217 assay demonstrated potential diagnostic and prognostic utility in an Asian cohort with concomitant CeVD.

Highlights

• The utility of plasma p-tau217 to detect brain amyloid beta pathology (Aβ+) was studied in an Asian cohort with concomitant cerebrovascular disease
• Plasma tau phosphorylated at threonine 217 (p-tau217) showed superior utility in detecting Aβ+ compared to neuroimaging measures, clinical workup, or other blood biomarkers including p-tau181, glial fibrillary protein (GFAP), and Aβ
• Higher plasma p-tau217 correlated with faster cognitive decline
• Plasma p-tau217 shows promise as an Alzheimer's disease (AD) diagnostic and prognostic biomarker in diverse populations