TABLE 2.
Number of AD biomarkers and studies for different blood components.
| Blood component | Number of biomarkers | Number of studies | Tested parameters and number of studies |
| Plasma | 86 | 48 | Aβ pathology (26), neuroinflammation (8), tau pathology (5), neurodegeneration (3), cholinergic dysfunction (1), oxidative stress (1), energy metabolic dysfunction (1), AD (3) |
| Serum | 41 | 15 | Aβ pathology (6), neuroinflammation (5), tau pathology (1), vascular dysregulation (1), neurodegeneration (1), AD (1) |
| Exosomes | 12 | 4 | Neurodegeneration (2), Aβ and tau pathology (1), tau pathology (1) |
| Platelets | 4 | 3 | Aβ pathology (2), tau pathology (1) |
| NeV | 8 | 3 | Tau pathology (1), neuroinflammation (1), AD (1) |
| RBC | 2 | 1 | α-synuclein pathology |
NeV, Neuronal-enriched extracellular vesicles; RBC, red blood cells.