Decreased plasma α-synuclein in idiopathic Parkinson’s disease patients after adjusting hemolysis factor

Abstract

Background Lewy bodies are pathological hallmarks for the diagnosis of Parkinson's disease, where the core components are composed of aggregated forms of α-synuclein (α-syn). Although α-syn has been investigated as a potential biomarker for PD, its usage has been limited and still remains controversial. Objective An accurate enzyme-linked immunosorbent assay (ELISA) was developed for the detection of α-syn in plasma. The hemolysis score was calculated to eliminate the additive α-syn levels from RBCs. Human plasma samples were collected in heparinized blood tubes from idiopathic Parkinson disease (IPD) and healthy control (HC). Result Hemolysis score had a strong correlation with the level of plasma α-syn. From the limited set of samples in this preliminary study, decreased α-syn concentrations were observed in patients with IPD in comparison to HC after adjusting for hemolysis factor. Similar results with a commercial ELISA kit were found for measuring α-syn from the same set of samples with lower correlation and the reduced accuracy of diagnosis than the current study. ConclusionThe adjustments for the hemolysis factor would be indispensable, supporting plasma α-syn as a potential surrogate biomarker for distinguishing IPD from HC.

Plasma and serum alpha-synuclein as a biomarker in Parkinson's disease: A meta-analysis

“…As lumbar puncture is an invasive procedure, differences in α-syn levels have been explored in more accessible biofluids, like blood. In this regard, several studies have showed contradictory results, some authors finding increased levels of plasma or serum α-syn in PD patients [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], whereas others found no changes [22][23][24][25][26][27][28][29][30][31][32][33][34][35] or even reduced levels [36,37]. The analysis of different proteoforms of α-syn, like oligomeric (o-syn) and phosphorylated (p-syn) forms, has raised equally variable results [13,22,26,28,32,[38][39][40].…”

Decreased Exosomal Acetylcholinesterase Activity in the Plasma of Patients With Parkinson’s Disease

“…Accordingly, α-syn has been studied extensively as a potential biomarker and indicator of disease progression in PD and its related synucleinopathies (El-Agnaf et al, 2003;Hong et al, 2010;Devic et al, 2011;Mollenhauer et al, 2011;Shi et al, 2011). However, inconsistent plasma α-syn data in PD have been reported, and the diagnostic performance of α-syn in biofluids was still insufficient for application in PD diagnosis (Lee et al, 2006;Li et al, 2007;Foulds et al, 2011Foulds et al, , 2013Gorostidi et al, 2012;Ishii et al, 2015;Lin et al, 2017;Shim et al, 2020). The absence of reliable biofluidic biomarkers for PD has limited the monitoring of disease progression or treatment response.…”

Alpha-Synuclein in Peripheral Tissues as a Possible Marker for Neurological Diseases and Other Medical Conditions

“…The results of studies addressing serum and/or plasma aSyn levels in PD patients compared with controls are summarized in Table 1 [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 5...…”