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A longitudinal study on α-synuclein in blood plasma as a biomarker for Parkinson's disease.

Foulds PG, Diggle P, Mitchell JD, Parker A, Hasegawa M, Masuda-Suzukake M, Mann DM, Allsop D - Sci Rep (2013)

Bottom Line: 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).

View Article: PubMed Central - PubMed

Affiliation: Division of Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, LA1 4AY, UK.

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.

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ROC curve to evaluate the utility of plasma phosphorylated α-syn levels in discriminating patients with PD from healthy controls.
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f4: ROC curve to evaluate the utility of plasma phosphorylated α-syn levels in discriminating patients with PD from healthy controls.

Mentions: Figure 4 displays an ROC curve constructed to evaluate the utility of measuring plasma phosphorylated α-syn levels as a means of discriminating between patients with PD and healthy controls. The area under the curve (AUC) gives an indication of predictive value, with AUC = 0.5 for a random association and AUC = 1 for perfect discrimination21. The AUC of 0.717 for phosphorylated α-synuclein is slightly better than the value of 0.68 calculated from our previously reported data with fewer participants19 and suggests that this protein has potential diagnostic value. On the other hand, AUC = 0.558 was obtained in the present study for ‘total α-syn’, suggesting that it has no diagnostic utility.


A longitudinal study on α-synuclein in blood plasma as a biomarker for Parkinson's disease.

Foulds PG, Diggle P, Mitchell JD, Parker A, Hasegawa M, Masuda-Suzukake M, Mann DM, Allsop D - Sci Rep (2013)

ROC curve to evaluate the utility of plasma phosphorylated α-syn levels in discriminating patients with PD from healthy controls.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3756331&req=5

f4: ROC curve to evaluate the utility of plasma phosphorylated α-syn levels in discriminating patients with PD from healthy controls.
Mentions: Figure 4 displays an ROC curve constructed to evaluate the utility of measuring plasma phosphorylated α-syn levels as a means of discriminating between patients with PD and healthy controls. The area under the curve (AUC) gives an indication of predictive value, with AUC = 0.5 for a random association and AUC = 1 for perfect discrimination21. The AUC of 0.717 for phosphorylated α-synuclein is slightly better than the value of 0.68 calculated from our previously reported data with fewer participants19 and suggests that this protein has potential diagnostic value. On the other hand, AUC = 0.558 was obtained in the present study for ‘total α-syn’, suggesting that it has no diagnostic utility.

Bottom Line: 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).

View Article: PubMed Central - PubMed

Affiliation: Division of Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, LA1 4AY, UK.

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.

Show MeSH
Related in: MedlinePlus