Table 1.
Demographic characteristics of patients with parkinsonian disorders or healthy controls (HC) included in the meta-analysis
| Study (first author, year) | Preanalytical factors Anticoagulant molecule: Platelet-depletion (Y/N) Coagulation factor depletion (Y/N) |
EV isolation method | CNS-EV antibody | EV confirmation method | EV lysis method | EV frozen (Y/N) | # PD | # MSA | # DLB | # PSP | # CBS | # RBD | # HC | Age (years) | Female (%) | Disease Duration (years) | HY scale | UPDRS III | MMSE | MoCA |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Plasma | ||||||||||||||||||||
| Shi et al. 2014 [38] |
EDTA Y (centrifuged at 3200 g for 15 min at 4 °C) N |
2000 g for 15 min to remove cell debris followed by 12,000 g for 30 min to remove larger EVs/particles followed by direct IP | L1CAM (clone UJ127) |
TEM WB for Alix and L1CAM |
1% Triton X-100 | N | 267 | 0 | 0 | 0 | 0 | 0 | 215 |
PD: 66.3 ± 9.1 HC: 65.7 ± 9.1 |
PD: 44.6% HC: 46.0% |
PD: 9.6 ± 6.6 | PD: 2.4 ± 0.7 | PD: 28.4 ± 12.6 | PD: 28.0 ± 2.6 | NR |
| Shi et al. 2016 [37] |
EDTA Y (centrifuged at 3200 g for 15 min at 4 °C) N |
2000 g for 15 min to remove cell debris followed by 12,000 g to remove larger EVs/particless for 30 min followed by direct IP | L1CAM (clone UJ127) |
TEM WB for Alix and L1CAM |
1% Triton X-100 | N | 91 | 0 | 0 | 0 | 0 | 0 | 106 |
PD: 65.0 ± 11.1 HC: 67.1 ± 7.4 |
PD: 28.6% HC: 45.3% |
PD: 6.0 ± 4.6 | PD: 2.2 ± 0.7 | PD: 26.3 ± 13.8 | PD: 27.6 ± 3.0 | NR |
| Zhao et al. 2019 [50] |
NR N Y |
1500 g for 20 min with thrombin to deplete the coagulation factors followed by ExoQuick (Systems Biosciences) treatment to the supernatant | L1CAM (clone 5G3) | TEM | Glycine–hydrochloride and DBS-2 with BSA and 0.10% Tween 20 and incubation for 10 min at 37 °C | Frozen at −80 °C after lysis |
39 Early: 22 Advanced: 17 |
0 | 0 | 0 | 0 | 0 | 40 |
PD: 67.5 ± 6.9 Early: 65.2 ± 11.2 Advanced: 67.5 ± 6.8 HC: 66.6 ± 8.8 |
PD: 41.0% HC: 57.5% |
PD: 5.0 ± 3.2 Early: 3.9 ± 2.5 Advanced: 6.4 ± 3.6 |
NR |
PD: 48.6 ± 21.0 Early: 37.8 ± 15.2 Advanced: 62.6 ± 19.3 |
NR | NR |
| Niu et al. 2020 [25] |
NR N N |
2000 g for 15 min to remove cell debris followed by 12,000 g for 30 min to remove larger EVs/particles followed by direct IP | L1CAM (clone UJ127) |
TEM TRPS WB for CD63 and L1CAM |
1% Triton X-100 | N |
53 Early: 36 Advanced: 17 |
0 | 0 | 0 | 0 | 20 | 21 |
PD: 65.0 ± 5.3 Early: 64.2 ± 4.9 Advanced: 66.5 ± 5.9 RBD: 63.2 ± 6.0 HC: 64.0 ± 5.4 |
PD: 53.0% Early: 50.0% Advanced: 59.0% RBD: 40.0% HC: 48.0% |
NR |
PD: 2.0 ± 0.5 Early: 1.5 ± 0.5 Advanced: 3.0 ± 0.5 RBD: NR |
PD: 22.3 ± 10.3 Early: 18.4 ± 7.5 Advanced: 29.7 ± 11.1 RBD: NR |
PD: 27.6 ± 2.6 Early: 28.2 ± 1.6 Advanced: 26.5 ± 3.6 RBD: NR |
PD: 23.6 ± 3.6 Early: 24.1 ± 3.3 Advanced: 22.5 ± 4.1 RBD: NR |
| Zou et al. 2020 [52] |
EDTA Y (1600 × g for 20 min at NR °C) N |
1000 g for 20 min to remove cells followed by 1600 g for 20 min to deplete platelets and samples were stored at − 80 °C. Thawed samples were centrifuged for 2,000 g for 15 min followed by 12,000 g for 30 min to remove larger EVs/particles followed by direct IP | L1CAM (clone UJ127) |
TEM NTA WB for CD9, CD63 and TSG101 |
1% Triton X-100 | N |
93 Early: 51 Advanced: 42 |
0 | 0 | 0 | 0 | 0 | 85 |
PD: 66.9 ± 9.5 Early: 64.7 ± 10.6 Advanced: 67.5 ± 8.1 HC: 66.2 ± 10.3 |
PD: 43.0% Early: 43.1% Advanced: 42.9% HC: 43.5% |
PD: 4.3 ± 2.5 Early: 2.0 ± 3.4 Advanced: 5.3 ± 3.1 |
PD: 2.8 ± 0.5 Early: 1.5 ± 0.5 Advanced: 3.0 ± 0.5 |
PD: 28.7 ± 16.0 Early: 22.0 ± 18.5 Advanced: 31.4 ± 15.3 |
PD: 24.3 ± 2.9 Early: 28.7 ± 2.6 Advanced: 21.9 ± 2.6 |
NR |
| Yu et al. 2020 [49] |
NR N N |
2000 g for 15 min to remove cell debris followed by 12,000 g for 30 min to remove larger EVs/particles followed by direct IP |
L1CAM (clone UJ127) for nEVs CNPase (clone mABcam 44,289) for oEVs |
NTA TEM WB for Alix, CD9 and CNPase |
1% Triton X-100 | N | 34 | 32 | 0 | 0 | 0 | 0 | 31 |
PD: 63.6 ± 8.0 MSA: 63.0 ± 6.9 HC: 64.3 ± 7.5 |
PD: 41.2% MSA: 40.6% HC: 51.6% |
PD: 4.0 ± 2.2 MSA: 4.0 ± 2.8 |
NR |
PD: 21.4 ± 10.6 MSA (UMSARS): 24.1 ± 10.6 |
NR | NR |
| Yan et al. 2022 [48] |
NR N Y |
ExoQuick (Systems Biosciences) | L1CAM (clone UJ127) |
NTA TEM WB for Alix, Flotillin-1 and CD63 |
RIPA | Frozen at −20 °C after lysis |
44 Early: 28 Advanced: 16 |
0 | 0 | 0 | 0 | 101 | 48 |
PD: 64.2 ± 9.6 Early: 63.2 ± 9.8 Advanced: 65.9 ± 9.2 RBD: 61.9 ± 7.9 HC: 61.5 ± 7.1 |
PD: 56.8% Early: 53.6% Advanced: 62.5% RBD: 56.4% HC: 54.2% |
PD: 3.7 ± 3.8 Early: 2.5 ± 3.0 Advanced: 5.7 ± 4.1 RBD: NR |
PD: 2.1 ± 1.0 Early: 1.6 ± 0.5 Advanced: 3.1 ± 0.8 RBD: NR |
PD: 32.0 ± 19.7 Early: 21.8 ± 10.7 Advanced: 49.7 ± 19.5 RBD: NR |
PD: 23.7 ± 6.2 Early: 25.3 ± 4.8 Advanced: 21.1 ± 7.4 RBD: 21.8 ± 5.9 |
PD: 19.2 ± 7.1 Early: 21.0 ± 5.8 Advanced: 15.9 ± 8.2 RBD: 16.6 ± 6.4 |
| Jiao et al. 2023 [18] |
NR N N |
2000 g for 15 min to remove cell debris followed by 12,000 g for 30 min to remove larger EVs/particles followed by direct IP | L1CAM (clone UJ127) |
TEM TRPS WB for Alix and L1CAM |
1% Triton X-100 | N | Early: 50 | 0 | 0 | 0 | 0 | 0 | 50 |
PD: 64.3 ± 5.6 HC: 64.0 ± 5.8 |
PD: 56.0% HC: 50.0% |
PD: 2.3 ± 1.3 | PD: 1.6 ± 0.4 | PD: 21.9 ± 8.6 | PD: 28.1 ± 1.6 | PD: 24.3 ± 3.0 |
| Wang et al. 2023 [46] |
EDTA N N |
3200 g for 15 min to remove cell debris and stored at −80 °C. Thawed samples were centrifuged for 2000 g for 15 min followed by 12,000 g for 30 min to remove larger EVs/particles followed by direct IP |
L1CAM (clone UJ127) for nEVs GLT-1 (clone ABED-10) for aEVs |
FC NTA TEM WB for Alix and CD9 |
NA | N | 106 | 47 | 0 | 0 | 0 | 0 | 103 |
PD: 60.9 ± 13.9 MSA: 61.2 ± 12.3 HC: 56.5 ± 12.5 |
PD: 44.3% MSA: 46.8% HC: 43.7% |
PD: 6.4 ± 4.4 MSA: 3.2 ± 1.6 |
NR | NR | NR | NR |
| Chen et al. 2023 [5] |
NR N N |
2000 g for 20 min followed by 10,000 g for 20 min to remove larger EVs/particles followed by Total Plasma Exosome Isolation Kit (ThermoFisher Scientific) followed by IP | L1CAM (clone 5G3) |
TEM WB for CD63 |
0.2% Triton x-100 | Frozen at −80 °C after lysis |
43 Early: 16 Advanced: 27 |
0 | 0 | 0 | 0 | 0 | 34 |
PD: 66.6 ± 9.6 Early: 64.5 ± 10.8 Advanced: 67.9 ± 8.8 HC: 63.7 ± 10.0 |
PD: 39.5% Early: 56.2% Advanced: 29.6% HC: 50.0% |
PD: 4.4 ± 3.5 Early: 2.3 ± 2.5 Advanced: 5.6 ± 3.8 |
PD: 2.7 ± 1.2 Early: 1.4 ± 0.5 Advanced: 3.5 ± 0.8 |
NR | NR | NR |
| Serum | ||||||||||||||||||||
| Si et al. 2019 [39] |
NA N NA |
3000 g for 15 min at 4 °C to remove cells and debris followed by ExoQuick (Systems Biosciences) | L1CAM (clone UJ127) |
EM WB for CD9 |
1% Triton X-100 | N | 38 | 0 | 0 | 0 | 0 | 0 | 18 |
PD: 62.4 ± 9.7 TD: 62.7 ± 10.6 NTD: 62.1 ± 10.6 HC: 62.7 ± 2.3 |
PD: 50.0% TD: 45.4% NTD: 50.0% HC: 55.5% |
PD: 2.3 ± 1.8 TD: 1.6 ± 1.2 NTD: 3.0 ± 2.5 |
PD: 1.7 ± 0.6 TD: 1.6 ± 0.6 NTD: 1.7 ± 0.5 |
PD: 18.6 ± 10.2 TD: 18.3 ± 9.4 NTD: 18.9 ± 10.9 |
NR | NR |
| Jiang et al. 2020 [17] |
NA N NA |
300 g for 10 min, 2000 g for 20 min and 10,000 g to for 30 min to remove cellular debris, protein aggregates and fatty material followed by direct IP | L1CAM (clone UJ127) |
NTA SEM WB for syntenin-1 and TSG101 |
1% Triton X-100 | N |
275 PDD: 45 |
14 | 21 | 35 | 45 | 65 | 144 |
PD: 68.9 ± 7.1 MSA: 68.1 ± 10.8 DLB: 68.5 ± 4.9 PSP: 68.0 ± 7.5 CBS: 61.1 + 7.2 RBD: 64.2 ± 8.3 HC: 68.1 ± 10.8 |
PD: 33.8% MSA: 40.0% DLB: 71.4% PSP: 48.6% CBS: 40.0% RBD: 4.6% HC: 34.7% |
PD: 7.5 ± 7.0 MSA: 4.9 ± 2.6 DLB: 3.4 ± 3.0 PSP: 2.8 ± 1.8 CBS: 1.9 ± 1.3 RBD: NR |
NR |
PD: 32.2 ± NR MSA: 27.7 ± NR DLB: 20.9 ± NR PSP: 24.5 ± NR CBS: 22.5 ± NR RBD: 5.1 ± NR |
NR |
PD: 22.7 ± NR MSA: 16.9 ± NR DLB: 16.3 ± NR PSP: 21.4 ± NR CBS: 22.3 ± NR RBD: 25.5 ± NR |
| Agliardi et al. 2021 [1] |
NA N NA |
ExoQuick (Systems Biosciences) | L1CAM (clone 5G3) |
Exo-Check Antibody Array NTA TEM WB for CD63, CD81, CD9, TSG101 and LCAM-1 |
M-PER | Frozen at −80 °C after lysis | 32 | 0 | 0 | 0 | 0 | 0 | 40 |
PD: 69.5 ± 8.6 HC: 57.4 ± 7.6 |
PD: 34.4% HC: 47.5% |
PD: 6.3 ± 3.6 | PD: 2.0 ± NR | PD: 28.5 ± 13.2 | NR | PD: 24.2 ± 2.5 |
| Jiang et al. 2021 [16] |
NA N NA |
300 g for 10 min, 2000 g for 20 min and 10,000 g for 30 min to remove cellular debris, protein aggregates and fatty material followed by direct IP | L1CAM (clone UJ127) |
NTA SEM WB for syntenin-1 and TSG101 |
1% Triton X-100 | N | 290 | 50 | 0 | 116 | 88 | 0 | 191 |
PD: 65.1 ± 7.8 MSA: 67.1 ± 10.0 PSP: 69.5 ± 2.2 CBS: 64.6 ± 7.2 HC: 64.4 ± 6.8 |
PD: 34.8% MSA: 30.0% PSP: 37.9% CBS: 53.4% HC: 41.9% |
PD: 7.4 ± 3.1 MSA: 5.2 ± 2.7 PSP: 3.5 ± 2.2 CBS: 3.3 ± 2.0 |
NR |
PD: 25.9 ± NR MSA: 27.7 ± NR PSP: 31.0 ± NR CBS: 36.1 ± NR |
NR |
PD: 26.8 ± NR MSA: 26.0 ± NR PSP: 22.0 ± NR CBS: 20.9 ± NR |
| Dutta et al. 2021 [11] |
NA N Y (few samples were obtained as plasma and treated with thrombin followed by high-speed centrifugation) |
2000 g for 10 min at 4 °C to remove cellular debris followed by ExoQuick (Systems Biosciences) |
L1CAM (clone 5G3) for nEVs MOG (clone D-2) for oEVs |
FC TEM TRPS WB for Alix, CD9, and CD81 |
RIPA | Frozen at −80 °C after lysis | 104 | 80 | 0 | 0 | 0 | 0 | 101 |
PD: 66.8 ± 9.3 MSA: 62.8 ± 8.1 HC: 64.9 ± 10.5 |
PD: 55.5% MSA: 51.2% HC: 55.4% |
PD: 7.0 ± 4.4 MSA: 5.0 ± 2.8 |
PD: 2.4 ± 0.9 MSA: 3.8 ± 1.9 |
PD: 20.7 ± 14.3 MSA: NR |
PD: 27.0 ± 4.2 MSA 27.2 ± 5.5 |
NR |
| Meloni et al. 2023 [24] |
NA N NA |
4000 g for 20 min at 4 °C followed by ExoQuick (Systems Biosciences) | L1CAM (clone 5G3) |
Exo-Check Antibody Array NTA TEM WB for CD63, CD81, CD9, TSG101 and LCAM-1 |
M-PER | Frozen at −80 °C after lysis | 70 | 0 | 0 | 21 | 19 | 0 | 0 |
PD: 69.5 ± 7.5 PSP: 72.8 ± 8.5 CBS: 71.9 ± 8.0 |
PD: 44.2% PSP: 47.6% CBS: 57.9% |
PD: 7.3 ± 5.6 PSP: 4.0 ± 1.6 CBS: 4.4 ± 3.1 |
PD: 2.1 ± 0.6 PSP: NR CBS: NR |
PD: 33.0 ± 14.4 PSP: NR CBS: NR |
NR |
PD: 25.1 ± 2.7 PSP: 17.8 ± 5.1 CBS: 17.0 ± 8.1 |
| Taha et al. 2023 [43] |
NA N Y (few samples were obtained as plasma and treated with thrombin followed by high-speed centrifugation) |
2000 g for 10 min at 4 °C to remove cellular debris followed by ExoQuick (Systems Biosciences) |
L1CAM (clone 5G3) for nEVs MOG (clone D-2) for oEVs |
FC TEM TRPS WB for Alix, CD9, and CD81 |
RIPA | Frozen at −80 °C after lysis | 46 | 30 | 0 | 0 | 0 | 0 | 32 |
PD: 66.8 ± 11.6 MSA: 62.7 ± 8.2 |
PD: 46.8% MSA: 56.7% |
PD: 8.1 ± 5.0 MSA: 62.7 ± 8.2 |
PD: 2.5 ± 1.0 MSA: 3.8 ± 1.0 |
PD: 25.1 ± 15.6 |
PD: 26.3 ± 6.4 MSA: 26.5 ± 9.3 |
NR |
| Sharafeldin et al. 2023 [35] |
NA N NA |
On-Chip Immunocapture | L1CAM (clone UJ127) |
DLS FM NTA WB for syntenin-1 and TSG101 |
1% Triton X-100 | N | 20 | 0 | 0 | 0 | 0 | 23 | 29 | NR | NR | NR | NR | NR | NR | NR |
aEVs astrocyte extracellular vesicles; Alix ALG-2-interacting protein X; CBS corticobasal syndrome; CFM confocal fluorescence microscopy; CNPase 2′,3′-cyclic-nucleotide 3′-phosphodiesterase; DLB dementia with Lewy body; DLS dynamic light scattering; ECLIA electrochemilumiscence ELISA; EDTA ethylenediaminetetraacetic acid; ELISA enzyme-linked immunosorbent assay; EM electron microscopy; EV– extracellular vesicle; FC flow-cytometry; FM fluorescence microscopy; GLT-1 glutamate transporter 1; HC healthy control; HY Hoehn and Yahr disease stage scale45; IP immunoprecipitation; L1CAM L1 cell adhesion molecule; MCI mild cognitive impairment; MMSE mini-mental state examination; MoCA Montreal cognitive assessment; MOG myelin oligodendrocyte glycoprotein; M-PER mammalian protein extraction reagent; MPs-CILA paramagnetic particle-based chemiluminescence immunoassay; MSA multiple system atrophy; NA not applicable; NC non-cognitively impaired; nEVs neuronal extracellular vesicles; NR not reported; NTA nanoparticle tracking analysis; NTD non tremor-dominant; oEVs oligodendrocyte extracellular vesicles; PD Parkinson's disease; PDD PD with dementia; pS129-α-syn phosphorylated α-syn at Ser 129; PSP progressive supranuclear palsy; RIPA radioimmunoprecipitation assay; SEM scanning EM; TD tremor-dominant; TEM transmission EM; TRPS tunable resistive pulse sensing; TSG101 tumor susceptibility gene 101 protein; UMSARS unified multiple system atrophy rating scale48; UPDRSIII Unified Parkinson's disease rating scale.49; WB Western blot