Alpha-Synuclein Detection Techniques in Neurodegenerative Disorders

Alpha-synuclein lies at the heart of a range of neurodegenerative disorders known as synucleinopathies, which include Parkinson’s disease, dementia with Lewy bodies and multiple system atrophy. Detection techniques have evolved from postmortem histology to in vivo and minimally invasive assays. Seed amplification methods such as real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA) sensitively detect misfolded α-synuclein in cerebrospinal fluid and serum by converting trace pathological seeds into measurable fibrils. Immunoprecipitation-enhanced RT-QuIC further refines specificity by enriching target seeds prior to amplification. Complementary advances in molecular imaging, employing novel positron emission tomography (PET) and single-photon emission computed tomography (SPECT) tracers, enable non-invasive visualisation and quantification of α-synuclein pathology in both central and peripheral tissues. Peripheral biopsies—skin, olfactory mucosa and salivary gland—are emerging as practical sources of pathological seeds, broadening diagnostic reach. High-sensitivity proximity extension assays and radioligand binding studies offer additional avenues to profile co-pathological markers and explore novel binding epitopes. Together, these approaches afford early and differential diagnosis, real-time monitoring of disease progression and objective assessment of target engagement in therapeutic trials.

Research from Nature Portfolio

A modified immunoprecipitation-based RT-QuIC assay has demonstrated exceptional performance in detecting pathogenic α-synuclein seeds in serum samples. By enriching seeds via antibody capture before amplification, this platform achieves high accuracy in distinguishing Parkinson’s disease and multiple system atrophy from controls. Crucially, the amplified seeds retain disease-specific conformational properties, enabling discrimination between synucleinopathies. In parallel, the development of a new fluorine-18 labelled PET tracer has enabled in vivo visualisation of α-synuclein aggregates. Clinical studies reveal clear tracer binding in regions affected by multiple system atrophy, with minimal uptake in Parkinson’s disease, offering a non-invasive means to differentiate these disorders and to monitor therapeutic interventions targeting α-synuclein.

Alpha-Synuclein Detection Techniques in Neurodegenerative Disorders publication trend

The graph below shows the total number of articles in alpha-synuclein detection techniques in neurodegenerative disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Alpha-synuclein: A presynaptic neuronal protein prone to misfolding and aggregation, forming oligomers and fibrils characteristic of synucleinopathies.

RT-QuIC (Real-Time Quaking-Induced Conversion): An ultrasensitive seed amplification assay that detects misfolded α-synuclein by inducing its fibrillisation in real time.

PMCA (Protein Misfolding Cyclic Amplification): A cyclic amplification technique that amplifies misfolded protein aggregates through repeated incubation and sonication cycles.

PET (Positron Emission Tomography): A molecular imaging modality that uses radiolabelled tracers to visualise and quantify pathological protein aggregates in living subjects.

Immunoprecipitation-based RT-QuIC: A hybrid assay combining antibody-mediated enrichment of α-synuclein seeds with RT-QuIC amplification for enhanced specificity.

Proximity Extension Assay: A multiplex immunoassay enabling quantification of low-abundance proteins by DNA-mediated signal amplification triggered by paired antibody binding.

References

1. Propagative α-synuclein seeds as serum biomarkers for synucleinopathies. Nature Medicine (2023).
2. The α-synuclein PET tracer [18F] ACI-12589 distinguishes multiple system atrophy from other neurodegenerative diseases. Nature Communications (2023).
3. Translational molecular imaging and drug development in Parkinson’s disease. Molecular Neurodegeneration (2023).
4. High diagnostic performance of independent alpha-synuclein seed amplification assays for detection of early Parkinson’s disease. Acta Neuropathologica Communications (2021).
5. Skin α-Synuclein Aggregation Seeding Activity as a Novel Biomarker for Parkinson Disease. JAMA Neurology (2020).
6. Efficient RT-QuIC seeding activity for α-synuclein in olfactory mucosa samples of patients with Parkinson’s disease and multiple system atrophy. Translational Neurodegeneration (2019).
7. Large-scale proximity extension assay reveals CSF midkine and DOPA decarboxylase as supportive diagnostic biomarkers for Parkinson’s disease. Translational Neurodegeneration (2023).
8. Binding of the Radioligand SIL23 to α-Synuclein Fibrils in Parkinson Disease Brain Tissue Establishes Feasibility and Screening Approaches for Developing a Parkinson Disease Imaging Agent. PLOS ONE (2013).