α‐Synuclein species in plasma neuron‐derived extracellular vesicles as biomarkers for iRBD

Abstract Objective Isolated REM sleep behavior disorder (iRBD) is considered as the strongest predictor of Parkinson's disease (PD). Reliable and accurate biomarkers for iRBD detection and the prediction of phenoconversion are in urgent need. This study aimed to investigate whether α‐Synuclein (α‐Syn) species in plasma neuron‐derived extracellular vesicles (NDEVs) could differentiate between iRBD patients and healthy controls (HCs). Methods Nanoscale flow cytometry was used to detect α‐Syn‐containing NDEVs in plasma. Results A total of 54 iRBD patients and 53 HCs were recruited. The concentrations of total α‐Syn, α‐Syn aggregates, and phosphorylated α‐Syn at Ser129 (pS129)‐containing NDEVs in plasma of iRBD individuals were significantly higher than those in HCs (p