Faculty, Staff and Student Publications
Publication Date
4-1-2025
Journal
Annals of Neurology
Abstract
Objective: Remote identification of individuals with severe hyposmia may enable scalable recruitment of participants with underlying alpha-synuclein aggregation. We evaluated the performance of a staged screening paradigm using remote smell testing to enrich for abnormal dopamine transporter single-photon emission computed tomography imaging (DAT-SPECT) and alpha-synuclein aggregation.
Methods: The Parkinson's Progression Markers Initiative (PPMI) recruited participants for the prodromal cohort who were 60-years and older without a Parkinson's disease diagnosis. Participants were invited to complete a University of Pennsylvania Smell Identification Test (UPSIT) independently through an online portal. Hyposmic participants were invited to complete DAT-SPECT, which determined eligibility for enrollment in longitudinal assessments and further biomarker evaluation including cerebrospinal fluid alpha-synuclein seed amplification assay (aSynSAA).
Results: As of January 29, 2024, 49,843 participants were sent an UPSIT and 31,293 (63%) completed it. Of UPSIT completers, 8,301 (27%) scored < 15th percentile. Of 1,546 who completed DAT-SPECT, 1,060 (69%) had DAT-SPECT binding < 100% expected for age and sex. Participants with an UPSIT < 10th percentile (n = 1,221) had greater likelihood of low DAT-SPECT binding compared to participants with an UPSIT in the 10th to 15th percentile (odds ratio, 3.01; 95% confidence interval, 1.85-4.91). Overall, 55% (198/363) of cases with UPSIT < 15th percentile and DAT-SPECT < 100% had positive aSynSAA, which increased to 70% (182/260) when selecting for more severe hyposmia (UPSIT < 10th percentile).
Interpretation: Remote screening for hyposmia and reduced DAT-SPECT binding identifies participants with a high proportion positive aSynSAA. Longitudinal data will be essential to define progression patterns in these individuals to ultimately inform recruitment into disease modification clinical trials. ANN NEUROL 2025;97:730-740.
Keywords
Humans, Male, Female, Aged, Middle Aged, Biomarkers, Tomography, Emission-Computed, Single-Photon, alpha-Synuclein, Dopamine Plasma Membrane Transport Proteins, Prodromal Symptoms, Parkinson Disease, Synucleinopathies, Olfaction Disorders, Cohort Studies
DOI
10.1002/ana.27158
PMID
39719857
PMCID
PMC11889527
PubMedCentral® Posted Date
12-24-2024
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes
Included in
Bioinformatics Commons, Biomedical Informatics Commons, Genetic Phenomena Commons, Medical Genetics Commons, Neurology Commons, Oncology Commons