Table 2.
Agreement between CSF positivity and [18F]flutemetamol PET positivity using dichotomized measures based on the diagnoses made before [18F]flutemetamol PET
| CSF | [18F]Flutemetamol PETa | CSF biomarkerb | Number (%) of patients positive | ||||
|---|---|---|---|---|---|---|---|
| MCI (n = 86c) | AD (n = 38c) | Non-AD disorder (n = 9c) | Dementia NOS (n = 15c) | SCD (n = 4c) | |||
| Positive | Positive | Aβ1-42 | 25 (29) | 19 (50) | 2 (22) | 2 (13) | – |
| p-tau | 30 (35) | 19 (50) | 2 (22) | 2 (13) | 3 (75) | ||
| t-tau | 29 (34) | 20 (52) | 3 (33) | 2 (13) | 3 (75) | ||
| Negative | Aβ1-42 | 11 (13) | 3 (8) | 3 (33) | 2 (13) | – | |
| p-tau | 3 (3) | 4 (10) | 2 (22) | 3 (20) | – | ||
| t-tau | 3 (3) | 3 (8) | 1 (11) | 3 (20) | – | ||
| Negative | Positive | Aβ1-42 | 23 (27) | 6 (16) | – | – | 3 (75) |
| p-tau | 18 (21) | 6 (16) | – | – | – | ||
| t-tau | 19 (22) | 6 (16) | – | – | – | ||
| Negative | Aβ1-42 | 27 (31) | 10 (26) | 4 (45) | 11 (74) | 1 (25) | |
| p-tau | 35 (41) | 9 (24) | 5 (56) | 10 (67) | 1 (25) | ||
| t-tau | 35 (41) | 9 (24) | 5 (56) | 10 (67) | 1 (25) | ||
Concordance (both biomarkers positive or negative): CSF-positive/PET-positive and CSF-negative/PET-negative. Discordance (only one of two biomarkers positive): CSF-positive/PET-negative (isolated CSF positivity) and CSF-negative/PET-positive (isolated PET positivity)
aThe cut-off value used for [18F]flutemetamol SUVR was 0.60, in combination with visual assessment
bThe cut-off values used to binarize CSF biomarkers were <550 ng/L for Aβ1-42, >80 ng/L for p-tau and >400 ng/L for t-tau
cNumber of patients in whom CSF was sampled