Plasma marker predicts amyloid-β pathology in the brain

Alzheimer’s disease is characterized by the deposition of amyloid-β (Aβ) peptide in the brain. The only available methods to reliably determine the levels of Aβ deposition are Aβ-PET imaging or measurement of Aβ levels in the cerebrospinal fluid. Therefore, identifying a blood-based biomarker that can be assessed in a minimally invasive and cost-effective manner is highly desirable. Katsuhiko Yanagisawa and colleagues use immunoprecipitation and mass spectrometry to measure the levels of several Aβ-related peptide fragments in blood. The APP_669–711/Aβ_1–42 and Aβ_1–40/Aβ_1–42 ratios and a composite score reliably predict individual levels of Aβ deposition in the brain. These results highlight the potential clinical utility of plasma biomarkers in predicting brain Aβ burden at an individual level.