Neurology ·
Skin α-Synuclein Assay Shows Potential to Distinguish MSA From Parkinson’s Disease
In a blinded, cross-sectional study of 117 participants, a skin α-synuclein seed amplification assay detected synucleinopathy and differentiated multiple system atrophy (MSA) from Parkinson’s disease (PD) using assay kinetics. The findings support further evaluation of the assay as a diagnostic biomarker, but do not establish it for routine clinical use.
- Assay detected synucleinopathy with 82.2% sensitivity.
- Specificity versus controls was 90%.
- Kinetic measures distinguished MSA from PD.
- Further clinical validation is needed.
Misdiagnosis between MSA and PD remains common. In this blinded, cross-sectional study, investigators analyzed 308 skin biopsies from 117 participants: 42 with PD, 31 with MSA, 30 controls and 14 with progressive supranuclear palsy. They assessed a standardized, thioflavin T fluorescence-based α-synuclein seed amplification assay and used predefined thresholds based on neuropathologically confirmed brain samples.
The assay detected synucleinopathy (PD or MSA) with 82.2% sensitivity and 90% specificity versus controls. Maximum fluorescence and lag time distinguished PD from MSA, with areas under the receiver operating characteristic curve of 0.93 and 0.91, respectively. Among assay-positive cases, a mean maximum-fluorescence cutoff correctly classified the underlying synucleinopathy in 49 of 60 cases (81.7%). Findings were supported by reproducibility testing and analyses of subsets with matched cerebrospinal fluid, MRI or postmortem brain data.
The results suggest that skin α-synuclein amplification may help distinguish synucleinopathies, but the study does not establish routine diagnostic performance in broader clinical populations. The cohort was modest, and the authors describe the assay as having potential; independent clinical validation would be needed before its use could guide diagnosis or management.
In practice
For patients being evaluated for PD or MSA, skin α-synuclein seed amplification is a promising investigational diagnostic approach: in this cohort it detected synucleinopathy with 82.2% sensitivity and 90% specificity versus controls, and assay kinetics differentiated PD from MSA. However, classification was correct in 81.7% of assay-positive cases, and the study included only 117 participants. These results do not establish performance in broader practice or justify changing diagnostic workups; further clinical validation is needed.
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Movement Disorders: Skin Seed Amplification Assay Differentiates Multiple System Atrophy from Parkinson's Disease ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.