Synucleinopathies, including Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), are characterized by the accumulation of α-synuclein aggregates. Early and accurate diagnosis remains a critical challenge in managing these disorders. The Seed Amplification Immunoassay (SAIA) is a highly sensitive and specific diagnostic platform capable of detecting α-synuclein aggregates at attogram levels in various biofluids and tissue samples.

Our work on the SAIA highlights its remarkable utility in diagnosing synucleinopathies across diverse clinical and research applications. By leveraging its exceptional specificity, SAIA reliably differentiates synucleinopathies such as Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy from other neurodegenerative conditions.

The assay’s high sensitivity enables the detection of α-synuclein aggregates at early stages of disease progression in cerebrospinal fluid and tissue samples, including brain and skin homogenates. Its application in prodromal cases, such as REM sleep behavior disorder (RBD), underscores its potential for identifying disease before the onset of motor symptoms. Furthermore, SAIA’s adaptability to skin biopsies expands its diagnostic versatility, offering a minimally invasive option for clinical settings.

These findings establish SAIA as a transformative tool for the early diagnosis and monitoring of synucleinopathies, paving the way for timely interventions and personalized therapeutic strategies to improve patient outcomes.