This proposal seeks to 1) determine whether there are biomarkers associated with Parkinson's disease (PD) susceptibility and/or progression in exosome-proteomes derived from PD patients versus controls, and 2) to determine if LRRK2 expression and/or phosphorylation are significantly lowered in the exosomes of individuals treated with the potent LRRK2 kinase inhibitor sunitinib (a multi-kinase inhibitor compound), to establish an assay for on-target effects for future LRRK2 inhibitor clinical trials.

Inclusion Criteria:

Parkinson's disease inclusion criteria:

Inclusion criteria will be based on UK Brain Bank criteria for the clinical diagnosis of PD. These require 1) the presence of bradykinesia and either rest tremor or rigidity; 2) asymmetric onset; 3) progressive motor symptoms 4) age at onset 21-99 years.

Control inclusion criteria: ages of between 21-99 years, a lack of PD in first-degree blood relatives, and a lack of positive responses on more than 3 items on the PD Screening Questionnaire.

Exclusion Criteria:

For all subjects:

include atypical features indicative of a Parkinson-Plus disorder (Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA), Corticobasal Degeneration (CBD)) including cerebellar signs, supranuclear gaze palsy, apraxia and other cortical signs, or prominent autonomic failure, neuroleptic treatment at time of onset of parkinsonism, active treatment with a neuroleptic at time of study entry, History of repeated strokes with stepwise progression of parkinsonism, history of repeated head injury, history of definite encephalitis, prominent gait imbalance early in the course (< 5 years), dementia, known severe anemia (hematocrit <30), history of kidney disease and/or current or past glomerular filtration rate (GFR) <60 possibly indicative of kidney disease, or a serious comorbidity that may interfere with participation in the study.

Neurology clinic