Table 4.

Biomarker profiles and categories for the NIA_AA Framework (41).

A|T|(N) profiles	Biomarker category
A−|T−|(N)−	Normal AD biomarkers
A+|T−|(N)−	Alzheimer’s pathologic change	Alzheimer’s continuum
A+|T+|(N)−	Alzheimer’s disease
A+|T+|(N)+	Alzheimer’s disease
A+|T−|(N)+	Alzheimer’s & concomitant suspected non-alzheimer’s pathologic change
A−|T+|(N)−	Non-AD pathologic change
A−|T−|(N)+	Non-AD pathologic change
A−|T+|(N)+	Non-AD pathologic change

A=amyloid plaque burden measured by CSF Aβ42 or Aβ42/Aβ40 or by amyloid PET; T=tau pathology measured by CSF p-tau181 or tau PET; (N) neurodegeneration, measureable using FDG-PET or MRI. When blood based biomarkers become validated they may substitute for CSF biomarkers.