Table 3.

Aβ and tau biomarker profiles.

Biomarker profile	Pathology
A−/T−	Normal biomarkers
A+/T−	Aβ pathology
A−/T+	Abnormal tau phosphorylation and/or tau tangle pathology
A+/T+	Alzheimer's pathology

A: Aβ status; AD: Alzheimer's disease; T: tau status. Aβ pathology indicates an abnormal Aβ biomarker with normal fluid p-tau and tau tangle PET. Abnormal tau phosphorylation consists of abnormal fluid p-tau with normal tau tangle PET. Tau tangle pathology consists of an abnormal tau tangle PET biomarker regardless of fluid p-tau levels. Alzheimer's pathology consists of abnormal Aβ plus fluid p-tau and/or tau tangle PET.