Tissue and fluid biomarkers for PD
| Source | Medium | Main techniques | Candidate markers | Invasiveness | Cost | Suitability for screening |
|---|---|---|---|---|---|---|
| Cerebrospinal fluid | Fluid | Assay, electrophoresis, mass-spec | t-α-syn, p-α-syn, t-tau, p-tau, NFL | +++ | ++ | ++ |
| Blood | Fluid | Assay, electrophoresis, mass-spec | Uric acid, inflammatory markers, IGF-1, ApoA1, DJ-1 | ++ | + | +++ |
| Saliva | Fluid | Assay, electrophoresis, mass-spec | α-syn, DJ-1 | + | + | +++ |
| Gut | Tissue biopsy | Immunohistochemistry | t-α-syn, p-α-syn | ++++ | +++ | ++ |
| Salivary gland | Tissue biopsy | Immunohistochemistry | t-α-syn, p-α-syn | ++++ | +++ | + |
| Skin | Tissue biopsy | Immunohistochemistry | t-α-syn, p-α-syn | +++ | ++ | +++ |
Invasiveness, cost and suitability for screening are estimated semiquantitatively on a four-point relative scale with + lowest and ++++ highest.
ApoA1, apolipoprotein A1; IGF-1, insulin like growth factor 1; NFL, neurofilament light chain; p-α-syn, phosphorylated α synuclein; t-α-syn, total α synuclein.