Table 2.
Protein Biomarkers in CSF and Plasma
| Target Marker | Mean concentrations (± SD) | P-value (change due to AD) | Plasma/CSF correlation | |||||
|---|---|---|---|---|---|---|---|---|
|
| ||||||||
| Plasma | CSF | |||||||
|
| ||||||||
| Healthy | AD | Healthy | AD | Plasma | CSF | Healthy | AD | |
| Aβ40 (pmol/L) | 9.36 ±1.65 | 9.00 ±1.10 | 161 ±76.6 | 175 ±53.4 | 0.8968 | 0.5787 | 0.93 | 0.66 |
| Aβ42 (pmol/L) | 4.91 ±0.90 | 3.54 ±0.41 | 43.8 ±21.6 | 25.5 ±10.1 | 0.0008* | 0.0493* | 0.61 | 0.14 |
| ApoE (µg/ml) | 5.86 ±1.28 | 4.98 ±0.99 | 10.08 ±2.88 | 10.05 ±1.62 | 0.1718 | 0.9809 | 0.02 | 0.54 |
| Clusterin (µg/ml) | 6.12 ±1.31 | 5.93 ±1.31 | 7.14 ±1.02 | 7.38 ±1.19 | 0.9046 | 0.5490 | 0.14 | 0.18 |
| Fibrinogen α-chain (µg/ml) | 348 ±401 | 323 ±354 | 8.77 ±13.08 | 12.2 ±8.36 | 0.7191 | 0.0887 | 0.30 | 0.87 |
| Keratin 9 (pg/ml) | 422 ±219 | 625 ±379 | 0.0 ±0.0 | 3.75 ±5.9 | 0.2721 | - | - | 0.24 |
| SPARCL1 (ng/ml) | 1957 ±1136 | 1271 ±557 | 1286 ±620 | 815 ±245 | 0.0887 | 0.0349* | 0.05 | 0.89 |
| Tau (ng/ml) | 75.1 ±14.3 | 63.4 ±11.9 | 61.5 ±17.6 | 63.9 ±11.7 | 0.0466* | 0.5490 | ≤ 0.0001 | 0.47 |
| Tetranectin (µg/ml) | 29.9 ±14.3 | 21.4 ±5.4 | 6.59 ±3.09 | 6.08 ±2.18 | 0.3498 | 0.9046 | ≤ 0.0001 | 0.58 |
Expression levels of the biomarker panel components were quantified in CSF and plasma samples using immunoassays. Variations between the cohorts were evaluated using the Mann-Whitney test. Spearman correlation coefficients were determined for protein values between the two sample types. A p-value 0.05 was considered statistically significant.
*
p ≤ 0.05.