Erythrocyte-derived extracellular vesicles and proteins associated with such vesicles as biomarkers for parkinson's disease

An in vitro method for clinically assessing Parkinson's disease, the method comprising

• (a) obtaining a preparation of isolated erythrocyte-derived extracellular vesicles (EEV) from a blood sample of a subject having or suspected of having Parkinson's disease;
• and
• (b) quantifying the expression level(s) of one or more protein biomarker(s) in the preparation of isolated EEV, wherein the one or more protein biomarker(s) comprises:
• (i) Alpha/beta hydrolase domain-containing protein 14B, if the subject has or is suspected of having mild or moderate Parkinson's disease;
• (ii) Alcohol dehydrogenase [NADP(+)], if the subject has or is suspected of having mild Parkinson's disease;
• (iii) ATP synthase subunit alpha, mitochondrial, if the subject has or is suspected of having moderate Parkinson's disease;
• or
• (iv) any combination of (i) to (iii),
• wherein the expression level of one or more of the protein biomarker(s) is indicative of, or correlates with, the subject's Parkinson's disease state.