αSyn	alpha-synuclein
αSyn-SAA	alpha-synuclein seed amplification assay
CI	confidence interval
CNS	central nervous system
DOR	diagnostic odds ratio
ECV	extracellular vesicle
GIT	gastrointestinal tract
MSA	multiple system atrophy
OM	olfactory mucosa
p-αSyn	phosphorylated alpha-synuclein
PD	Parkinson’s disease
PMCA	protein misfolding cyclic amplification
RT-QuIC	real-time quaking-induced conversion
SMG	submandibular gland