MAPT and amyloidosis: Plasma p-tau217 shows a steep increase after Aβ biomarkers have become positive.44 An association between plasma p-tau and amyloid accumulation according to PET, already in the asymptomatic stage, has been demonstrated in large memory research cohorts mainly of older individuals, although younger than in our cohort.10,12,15,45 Fewer studies have reported the associations between plasma p-tau and CSF amyloid markers.