Table 2.
NIAA-AA Research Framework showing AT(N) biomarker groupings associated with disease categories (top) and AT(N) definitions (bottom).
| AT(N) biomarker grouping | Disease category | |
|---|---|---|
| A−T−(N)− | Normal AD biomarkers | |
| A + T−(N)− | Alzheimer’s pathologic change | |
| A + T+(N)− | Alzheimer’s disease | |
| A + T+(N)+ | Alzheimer’s disease | |
| A + T−(N)+ | Alzheimer’s and concomitant non-AD pathology | |
| A−T+(N)− | Non-AD pathology | |
| A−T−(N)+ | Non-AD pathology | |
| A−T+(N)+ | Non-AD pathology | |
| AT(N) definitions | ||
| A | Aggregated Aβ (plaques); Aβ42 or Aβ42/40 ratio elevated in brain (reduced in CSF) | |
| T | Aggregated Tau (tangles); elevated pTau | |
| N | Neurodegeneration; elevated total Tau | |
+ indicates presence, − indicates absence of change in biomarker.
Adapted from Jack, C. R., Jr., Bennett, D. A., Blennow, K., Carrillo, M. C., Dunn, B., Haeberlein, S. B., et al. (2018). NIA-AA Research Framework: Toward a biological definition of Alzheimer’s disease. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, 14, 535–562.