Plasma Aβ42/Aβ40 determined by mass spectrometry is associated with longitudinal changes in amyloid accumulation, brain atrophy, and conversion to mild cognitive impairment due to Alzheimer’s disease in individuals with subjective cognitive decline: 5-year follow-up of the FACEHBI cohort

Our findings suggest that the plasma Aβ42/Aβ40 ratio is associated with future amyloid accumulation, brain atrophy, and conversion to prodromal AD in individuals with SCD. This biomarker may help characterize individuals with a higher likelihood of progression and could support earlier and more personalized strategies.