Table 4.
Potential salivary biomarkers associated with Parkinson’s disease (PD) described in studies.
| Potential Biomarker | Cohort (n) | Methods | Results | References |
|---|---|---|---|---|
| Total α-synuclein | PD: 20 HS: 20 |
ELISA assay | ↓ total α-synuclein in PD | Al-Nimer et al. [71] |
| PD: 60 HS: 40 |
ELISA assay | ↓ total α-synuclein in PD | Vivacque et al. [65] | |
| PD: 112 HS: 90 PSP: 20 |
ELISA assay | ↓ total α-synuclein in PD, ↑ total α-synuclein in PSP vs. PD | Vivacque et al. [66] | |
| PD: 201 HS: 67 |
Luminex assay Western blot Magnetic bead- based luminex assay |
No significant difference between PD and HC, no correlation with UPDRS score, ↓ with age in PD but not HC, associated with specific g-alleles | Kang et al. [72] | |
| PD: 25 HS: 15 |
ELISA assay | ↓ total α-synuclein in PD | Shaheen et al. [73] | |
| Oligomeric α-synuclein | PD: 60 HS: 40 |
ELISA assay | ↑ oligomeric α-synuclein in PD | Vivacque et al. [65] |
| PD: 25 HS: 15 |
ELISA assay | ↑ oligomeric α-synuclein/total α-synuclein in PD | Shaheen et al. [73] | |
| PD: 112 HS: 90 PSP: 20 |
ELISA assay | ↑ oligomeric α-synuclein/total α-synuclein in PD | Vivacque et al. [66] | |
| Oligomeric α-synuclein/total α-synuclein ratio | PD: 60 HS: 40 |
ELISA assay | ↑ oligomeric α-synuclein/total α-synuclein in PD | Vivacque et al. [65] |
| PD: 25 HS: 15 |
ELISA assay | ↑ oligomeric α-synuclein/total α-synuclein in PD | Shaheen et al. [73] | |
| PD: 112 HS: 90 PSP: 20 |
ELISA assay | ↑ oligomeric α-synuclein/total α-synuclein in PD | Vivacque et al. [66] | |
| PD: 201 HS: 67 |
Luminex assay Western blot Magnetic bead- based Luminex assay |
↑ oligomeric α-synuclein/total α-synuclein in PD with disease progression | Kang et al. [72] | |
| Deglycase-1 protein (DJ-1) | PD: 24 HS: 25 |
Western blot | No significant difference in DJ-1 between PD and HC | Devic et al. [74] |
| PD: 16 HS: 22 |
ELISA assay | ↑ DJ-1 in PD ↑ total protein in PD |
Masters et al. [75] | |
| Oxidative stress markers – heme oxygenase-1 (HO-1) | PD: 58 HS: 59 |
ELISA assay Western blot |
↑ HO-1 in PD | Song et al. [78] |
| Acetylcholinesterase (AChE) and total salivary protein (TP) | PD: 30 HS: 49 |
Ellman colorimetric method | ↑ AChE activity in PD ↑ AChE/TP ratio in PD No correlation between AChE, AChE/TP ratio and UPDRS scores |
Fedorova et al. [79] |
↑: increasing; ↓: decreasing; α-synuclein: alpha-synuclein; PD: Parkinson’s disease; HS: healthy subjects; PSP: progressive supranuclear palsy; UPDRS: Unified Parkinson’s Disease Rating Scale.