Plasma extracellular vesicles tau and β-amyloid as biomarkers of cognitive dysfunction of Parkinson's disease

The contribution of circulatory tau and -amyloid in Parkinson's disease (PD), especially the cognitive function, remains inconclusive. Extracellular vesicles (EVs) cargo these proteins throughout the bloodstream after they are directly secreted from many cells, including neurons. The present study aims to investigate the role of the plasma EV-borne tau and beta-amyloid as biomarkers for cognitive dysfunction in PD by investigating subjects with mild to moderate stage of PD (n = 116) and non-PD controls (n = 46). Plasma EVs were isolated, and immunomagnetic reduction-based immunoassay was used to assess the levels of alpha-synuclein, tau, and beta-amyloid 1-42 (A beta 1-42) within the EVs. Artificial neural network (ANN) models were then applied to predict cognitive dysfunction. We observed no significant difference in plasma EV tau and A beta 1-42 between PD patients and controls. Plasma EV tau was significantly associated with cognitive function. Moreover, plasma EV tau and A beta 1-42 were significantly elevated in PD patients with cognitive impairment when compared to PD patients with optimal cognition. The ANN model used the plasma EV alpha-synuclein, tau, and A beta 1-42, as well as the patient's age and gender, as predicting factors. The model achieved an accuracy of 91.3% in identifying cognitive dysfunction in PD patients, and plasma EV tau and A beta 1-42 are the most valuable factors. In conclusion, plasma EV tau and AO42 are significant markers of cognitive function in PD patients. Combining with the plasma EV alpha-synuclein, age, and sex, plasma EV tau and A beta 1-42 can identify cognitive dysfunction in PD patients. This study corroborates the prognostic roles of plasma EV tau and A beta 1-42 in PD.

Automated summary

Plasma extracellular vesicle (EV) tau and Aβ42 are significant markers of cognitive function in Parkinson's disease (PD) patients, and can help identify cognitive dysfunction. An artificial neural network model accurately predicts cognitive function in PD patients.