Abstract
Objective: To determine if blood neurofilament light chain (NfL) protein can discriminate between Parkinson disease (PD) and atypical parkinsonian disorders (APD) with equally high diagnostic accuracy as CSF NfL, and can therefore improve the diagnostic workup of parkinsonian disorders.
Methods: The study included 3 independent prospective cohorts: the Lund (n = 278) and London (n = 117) cohorts, comprising healthy controls and patients with PD, progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), and multiple system atrophy (MSA), as well as an early disease cohort (n = 109) of patients with PD, PSP, MSA, or CBS with disease duration ≤3 years. Blood NfL concentration was measured using an ultrasensitive single molecule array (Simoa) method, and the diagnostic accuracy to distinguish PD from APD was investigated.
Results: We found strong correlations between blood and CSF concentrations of NfL (ρ ≥ 0.73–0.84, p ≤ 0.001). Blood NfL was increased in patients with MSA, PSP, and CBS (i.e., all APD groups) when compared to patients with PD as well as healthy controls in all cohorts (p < 0.001). Furthermore, in the Lund cohort, blood NfL could accurately distinguish PD from APD (area under the curve [AUC] 0.91) with similar results in both the London cohort (AUC 0.85) and the early disease cohort (AUC 0.81).
Conclusions: Quantification of blood NfL concentration can be used to distinguish PD from APD. Blood-based NfL might consequently be included in the diagnostic workup of patients with parkinsonian symptoms in both primary care and specialized clinics.
Classification of evidence: This study provides Class III evidence that blood NfL levels discriminate between PD and APD.
GLOSSARY
- APD=
- atypical parkinsonian disorders;
- AUC=
- area under the curve;
- CBD=
- corticobasal degeneration;
- CBS=
- corticobasal syndrome;
- CI=
- confidence interval;
- MSA=
- multiple system atrophy;
- NfL=
- neurofilament light chain;
- p-tau=
- phosphorylated tau;
- PD=
- Parkinson disease;
- PSP=
- progressive supranuclear palsy;
- UPDRS=
- Unified Parkinson's Disease Rating Scale;
- WML=
- white matter lesion
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article. The Article Processing Charge was paid by the Swedish Research Council.
Coinvestigators are listed at Neurology.org.
Supplemental data at Neurology.org
Editorial, page 922
- Received April 22, 2016.
- Accepted in final form November 15, 2016.
- Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology
This is an open access article distributed under the terms of the Creative Commons Attribution Licence 4.0 (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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