Table 2.
Classification of core AD biomarkers and in fresh and frozen samples by using the A/T/(N) criteria. Number of changes in classification between biomarkers measured in fresh and stored at − 80 °C CSF samples are also reported. Samples with both pathologic Aβ42/Aβ40 ratio and pathologic p-tau (A+/T+) have been classified positive for AD. For “robust” AD diagnosis and AD exclusion (non-AD) a ± 10% tolerance was applied on the cutoffs of Aβ42/Aβ40 ratio and p-tau
| + (%) | − (%) | No. of changes (%) | |
|---|---|---|---|
| Aβ42/Aβ40 frozen | 39 (67%) | 19 (33%) | 1 (2%) |
| Aβ42/Aβ40 fresh | 40 (69%) | 18 (31%) | |
| p-tau frozen | 34 (59%) | 24 (41%) | 0 (0%) |
| p-tau fresh | 34 (59%) | 24 (41%) | |
| t-tau frozen | 34 (59%) | 24 (41%) | 2 (3%) |
| t-tau fresh | 36 (62%) | 22 (38%) | |
| AD frozen | 34 (59%) | 24 (41%) | 0 (0%) |
| AD fresh | 34 (59%) | 24 (41%) | |
| Robust AD frozen | 32 (55%) | 26 (45%) | 1 (2%) |
| Robust AD fresh | 33 (57%) | 25 (43%) | |
| Robust non-AD frozen | 24 (41%) | 34 (59%) | 1 (2%) |
| Robust non-AD fresh | 23 (40%) | 35 (60%) |