Interpreting positive plasma Aβ42/40 results when amyloid PET is negative

AAIC 2025 Abstract

Abstract

Background: The agreement between plasma Aβ42/40 and Aβ‐PET is approximately 75%, with a large portion of discrepancies due to positive plasma with negative PET results. Questions remain about whether these reflect brain Aβ changes detectable in plasma before PET‐detectable.

The paper