title: A longitudinal study on α-synuclein in blood plasma as a biomarker for Parkinson's disease.
abstract: There have been no longitudinal studies on α-synuclein as a potential biomarker for the progression of Parkinson's disease (PD). Here, blood plasma 'total α-synuclein' and 'Ser-129 phosphorylated α-synuclein' were assayed at 4-6 monthly intervals from a cohort of 189 newly-diagnosed patients with PD. For log-transformed data, plasma total α-synuclein levels increased with time for up to 20 yrs after the appearance of initial symptoms (p = 0.012), whereas phosphorylated α-synuclein remained constant over this same period. The mean level of phosphorylated α-synuclein, but not of total α-synuclein, was higher in the PD plasma samples taken at first visit than in single samples taken from a group of 91 healthy controls (p = 0.012). Overall, we conclude that the plasma level of phosphorylated α-synuclein has potential value as a diagnostic tool, whereas the level of total α-synuclein could act as a surrogate marker for the progression of PD.
authors.affiliation: Division of Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, LA1 4AY, UK.
authors.forename: Penelope G
authors.initials: PG
authors.lastname: Foulds
authors.forename: Peter
authors.initials: P
authors.lastname: Diggle
authors.forename: J Douglas
authors.initials: JD
authors.lastname: Mitchell
authors.forename: Angela
authors.initials: A
authors.lastname: Parker
authors.forename: Masato
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Masami
authors.initials: M
authors.lastname: Masuda-Suzukake
authors.forename: David M A
authors.initials: DM
authors.lastname: Mann
authors.forename: David
authors.initials: D
authors.lastname: Allsop
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000175:diagnosis; D010766:Phosphorylation; D012372:ROC Curve; D015203:Reproducibility of Results; D012737:Sex Factors; D051844:alpha-Synuclein / Q000097:blood*
chemical_list: D015415:Biomarkers; D051844:alpha-Synuclein