Tailoring thresholds for interpreting plasma p-tau217 levels.

Background: Plasma phosphorylated tau (p-tau) 217 test has emerged as a minimally invasive and accessible alternative to positron emission tomography imaging and cerebrospinal fluid analysis for Alzheimer's disease (AD) diagnostics. However, the diagnostic performance of p-tau217 across diverse cognitive and demographic subgroups remains underexplored. This multicentre cross-sectional study aimed to assess the diagnostic utility of plasma p-tau217 using a double cut-off approach in a large, diverse cohort, focusing on subgroup analyses based on cognitive status, age, sex, body mass index and ε4 carrier status.

Establishing Regional Aβ Cutoffs and Exploring Subgroup Prevalence Across Cognitive Stages Using BeauBrain Amylo.

Background And Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer's disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification. To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI).

Objective: We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages.