title: Phosphorylated α-synuclein can be detected in blood plasma and is potentially a useful biomarker for Parkinson's disease.
abstract: Parkinson's disease (PD) is characterized by the presence of Lewy bodies containing phosphorylated and aggregated α-synuclein (α-syn). α-Syn is present in human body fluids, including blood plasma, and is a potential biomarker for PD. Immunoassays for total and oligomeric forms of both normal and phosphorylated (at Ser-129) α-syn have been used to assay plasma samples from a longitudinal cohort of 32 patients with PD (sampled at mo 0, 1, 2, 3), as well as single plasma samples from a group of 30 healthy control participants. The levels of α-syn in plasma varied greatly between individuals, but were remarkably consistent over time within the same individual with PD. The mean level of phospho-α-syn was found to be higher (P=0.053) in the PD samples than the controls, whereas this was not the case for total α-syn (P=0.244), oligo-α-syn (P=0.221), or oligo-phospho-α-syn (P=0.181). Immunoblots of plasma revealed bands (at 21, 24, and 50-60 kDa) corresponding to phosphorylated α-syn. Thus, phosphorylated α-syn can be detected in blood plasma and shows more promise as a diagnostic marker than the nonphosphorylated protein. Longitudinal studies undertaken over a more extended time period will be required to determine whether α-syn can act as a marker of disease progression.
authors.affiliation: Division of Biomedical and Life Sciences, School of Health and Medicine, University of Lancaster, Lancaster, LA1 4AY, UK.
authors.forename: Penelope G
authors.initials: PG
authors.lastname: Foulds
authors.forename: J Douglas
authors.initials: JD
authors.lastname: Mitchell
authors.forename: Angela
authors.initials: A
authors.lastname: Parker
authors.forename: Roisin
authors.initials: R
authors.lastname: Turner
authors.forename: Gerwyn
authors.initials: G
authors.lastname: Green
authors.forename: Peter
authors.initials: P
authors.lastname: Diggle
authors.forename: Masato
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Mark
authors.initials: M
authors.lastname: Taylor
authors.forename: David
authors.initials: D
authors.lastname: Mann
authors.forename: David
authors.initials: D
authors.lastname: Allsop
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015151:Immunoblotting; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000175:diagnosis; D010766:Phosphorylation; D012372:ROC Curve; D051844:alpha-Synuclein / Q000097:blood* / Q000737:chemistry
chemical_list: D015415:Biomarkers; D051844:alpha-Synuclein