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Meta-Analysis
. 2019 May;40(5):929-938.
doi: 10.1007/s10072-019-03738-1. Epub 2019 Feb 4.

Plasma alpha-synuclein levels in patients with Parkinson's disease: a systematic review and meta-analysis

Anastasia Bougea  1   2 , Leonidas Stefanis  3 , George P Paraskevas  4 , Evangelia Emmanouilidou  3 , Kostas Vekrelis  3 , Elisabeth Kapaki  4
Affiliations
Meta-Analysis

Plasma alpha-synuclein levels in patients with Parkinson's disease: a systematic review and meta-analysis

Anastasia Bougea et al. Neurol Sci. 2019 May.

Abstract

Objective: To date, there are no definitive biomarkers for diagnose Parkinson's disease (PD). The detection of α-synuclein (α-Syn) in plasma of PD patients has yielded promising but inconclusive results. To determine the performance of α-Syn as a diagnostic biomarker of PD, we used a meta-analysis.

Methods: We identified 173 studies through a systematic literature review. From those, only studies reporting data on total α-Syn levels were included in the meta-analysis (10 publications, 1302 participants). Quality of studies was assessed by Newcastle-Ottawa scale.

Results: The α-Syn levels were significantly higher in PD patients than healthy controls (standardized mean difference [SMD] = 0.778, 95% confidence interval = 0.284 to 1.272, p = 0.002). Similar results were found after omitting any individual study from meta-analysis, with SMD ranges from 0.318 (95% CI = 0.064 to 0.572, p = 0.014) to 0.914 (95% CI = 0.349 to 1.480, p = 0.002). According to meta-regression analysis, increased mean patients age (slope = - 0.232, 95% CI = - 0.456 to - 0.008, p = 0.042), increased total number of participants (slope = - 0.007, 95% CI = - 0.013 to - 0.0004, p = 0.038), and increased percentage of males (slope = - 6.444, 95% CI = - 10.841 to - 2.047, p = 0.004) were associated with decreased SMD of α-Syn levels across studies. We did not find any significant association between the SMD in α-Syn levels and disease duration, disease severity, and quality of studies. Most of studies applied ELISA assays.

Conclusion: Total plasma α-Syn levels were higher in PD patients than controls. Analytical factors were important limitations.

Keywords: Biomarker; Meta-analysis; Meta-regression; Parkinson’s disease (PD); Plasma; α-Synuclein.

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References

    1. Dorsey ER, Constantinescu R, Thompson JP, Biglan KM, Holloway RG, Kieburtz K, Marshall FJ, Ravina BM, Schifitto G, Siderowf A, Tanner CM (2007) Projected number of people with Parkinson disease in the most populous nations, 2005 through 2030. Neurology 68(5):384–386. https://doi.org/10.1212/01.wnl.0000247740.47667.03 - DOI - PubMed
    1. Hughes AJ, Daniel SE, Kilford L, Lees AJ (1992) Accuracy of clinical diagnosis of idiopathic Parkinson's disease: a clinico-pathological study of 100 cases. J Neurol Neurosurg Psychiatry 55(3):181–184 - DOI - PubMed - PMC
    1. Spillantini MG, Crowther RA, Jakes R, Hasegawa M, Goedert M (1998) Alpha-Synuclein in filamentous inclusions of Lewy bodies from Parkinson's disease and dementia with lewy bodies. Proc Natl Acad Sci U S A 95(11):6469–6473 - DOI - PubMed - PMC
    1. Yu S, Li X, Liu G, Han J, Zhang C, Li Y, Xu S, Liu C, Gao Y, Yang H, Ueda K, Chan P (2007) Extensive nuclear localization of alpha-synuclein in normal rat brain neurons revealed by a novel monoclonal antibody. Neuroscience 145(2):539–555. https://doi.org/10.1016/j.neuroscience.2006.12.028 - DOI - PubMed
    1. Vivacqua G, Yin JJ, Casini A, Li X, Li YH, D'Este L, Chan P, Renda TG, Yu S (2009) Immunolocalization of alpha-synuclein in the rat spinal cord by two novel monoclonal antibodies. Neuroscience 158(4):1478–1487. https://doi.org/10.1016/j.neuroscience.2008.12.001 - DOI - PubMed

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