Table 2.
Biomarkers for the prodromal stage, diagnosis and progression of Parkinson’s disease (PD)
| Prodromal | Diagnostic | Progression |
|---|---|---|
| Clinical Slight MS (parkinsonism) NMS (hyposmia, RBD, EDS, constipation, depression, visual dysfunctions) |
Clinical MS (parkinsonism) NMS (hyposmia, RBD, EDS, constipation, depression, visual dysfunctions) |
Clinical MS (tremor, postural instability) NMS (hyposmia, cognitive decline, dysautonomia) |
| Biological fluids Blood (e.g., uric acid) |
Biological fluids CSF (α-synuclein species, DJ-1, LRKK2, metabolites) Blood (e.g., uric acid, apolipoprotein A1, LRKK2, inflammation factors) Saliva (α-synuclein species) Urine (biopyrin, LRKK2) |
Biological fluids CSF (α-synuclein, A ß oligomers, p-tau) Blood (e.g., uric acid, EGF, IGF-1, BDNF) |
| Pathology Biopsies (GI tract, salivary glands, olfactory mucosa, skin) |
Pathology Microbiota (gut, oral) |
– |
| Imaging Nuclear imaging (nigrostriatal degeneration at DaTscan) Transcranial ultrasound (substantia nigra hyperechogenicity) |
Imaging Structural imaging (nigral degeneration on MRI at ≥ 3 T) Functional imaging (remapping of cerebral connectivity at f-MRI) Nuclear imaging (nigrostriatal degeneration at DaTscan, microglial activation at PET imaging, post-ganglionic sympathetic nerve damage on cardiac and salivary gland scintigraphy) |
Imaging Functional imaging (hypometabolism patterns on FDG-PET) |
| – | Neurophysiology Altered ERG, VEP, LFPs |
– |
| – | Omics Proteomics, genomics, lipidomics, glycomics, metabolomics, interactomics |
– |
MS motor symptoms, NMS non-motor symptoms, RBD REM behaviour sleep disorder, EDS excessive daytime sleepiness, CSF cerebrospinal fluid, LRKK2 leucine-rich repeat kinase 2, EGF epidermal growth factor, IGF-1 insulin growth factor, BDNF brain-derived neurotrophic factor, GI gastrointestinal, DaTscan dopamine transporter imaging technique, MRI magnetic resonance imaging, f-MRI functional-magnetic resonance imaging, FDG-PET fluoro-2-deoxy-d-glucose positron-emission tomography, ERG electroretinogram, VEP visual evoked potential, LFPs long field potentials