Table 3.
ROC parameters for CSF biomarkers measured by different immunoassay platforms to discriminate participants with amyloid-PET positivity from those with amyloid-PET negativity
| Assay platforms | Parameters | Aβ42 | Aβ40 | T-tau | P-tau | T-tau/Aβ42 | P-tau/Aβ42 | Aβ42/Aβ40 |
|---|---|---|---|---|---|---|---|---|
| Luminex-AlzBio3 | n* | 125 | – | 124 | 125 | 124 | 125 | |
| ROC AUC | 0.897 | – | 0.694 | 0.810 | 0.852 | 0.892 | – | |
| Cut-off value | 380.6 pg/mL | – | 75.6 pg/mL | 21.02 pg/mL | 0.133 | 0.045 | – | |
| PPA (%) | 79.5 | – | 43.6 | 74.4 | 79.5 | 87.2 | – | |
| NPA (%) | 93.0 | – | 97.7 | 81.4 | 92.9 | 88.4 | – | |
| INNOTEST | n | 123 | 123 | 115 | 109 | 115 | 109 | 123 |
| ROC AUC | 0.860 | n.s. | 0.803 | 0.717 | 0.884 | 0.846 | 0.896 | |
| Cut-off value | 478.3 pg/mL | – | 247.3 pg/mL | 46.3 pg/mL | 0.484 | 0.079 | 0.091 | |
| PPA (%) | 76.9 | – | 77.8 | 73.5 | 83.3 | 80.0 | 89.7 | |
| NPA (%) | 94.1 | – | 73.4 | 60.8 | 94.9 | 87.8 | 83.3 | |
| Lumipulse | n | 123 | 126 | 123 | 123 | 123 | 123 | 123 |
| ROC AUC | 0.857 | n.s. | 0.791 | 0.839 | 0.842 | 0.840 | 0.856 | |
| Cut-off value | 642.1 pg/mL | – | 337 pg/mL | 36.0 pg/mL | 0.315 | 0.051 | 0.060 | |
| PPA (%) | 79.5 | – | 59.0 | 79.5 | 84.6 | 84.6 | 84.6 | |
| NPA (%) | 88.1 | – | 89.3 | 78.6 | 88.1 | 92.9 | 91.7 |
ROC AUC area under the receiver operating characteristic curve, PPA positive percent agreement, NPA negative percent agreement
*T-tau measured by Luminex of one sample and t-tau and p-tau measured using INNOTEST kits of 10 and 16 samples respectively were excluded following acceptance criteria of SOP, and two samples could not be measured due to loss of samples. 3 AD patients with Aβ-PET negative and normal CSF Aβ42 level were excluded to follow the A/T/N criteria for biological definition of AD