Validation and clinicaldevelopment of plasma EV protein biomarkers for minimally-invasive detection of Alzheimersdisease - PROJECT SUMMARY
Over 6 million Americans currently live with Alzheimer's disease (AD), and this number is projected
to increase to 16 million by 2050. The consensus is arising in the field that in order to treat AD
effectively, early detection at the MCI stage is a must. Thus, there is a critical need for a novel
minimally invasive and cost-effective diagnostic assay capable of such early detection. Cell-secreted
extracellular vesicles (EVs) recently gained significant attention in the fields of liquid biopsy and AD
research. Within the scope of biomarker detection, EVs offer numerous benefits for clinical analysis,
including non-invasive collection, a suitable sample source for longitudinal disease monitoring, ability
to cross the blood-brain barrier, higher stability and sample volumes, faster processing times and
lower cost. Multiple reports linked EVs to neurodegeneration and have been able to couple exosome
load in CSF to AD progression. However, the analysis of plasma exosomes and other EV has not
really been possible for early AD detection. The procedures for plasma biomarker analysis are very
long and cumbersome due to extremely low target levels and high background of free plasma
proteins. In order to enable better biomarker discovery and AD diagnosis, a more reliable and
efficient approach is needed, capable of enriching potential AD-associated proteins with higher purity.
In the NIH SBIR Phase I portion of this study, we have developed a novel method for fast and
reproducible capture and isolation of EVs with >95% recovery yield and >99.9% purity from plasma
samples. We then implemented this EV capture approach to discover novel potential AD markers in
plasma EVs with, which showed a clear and consistent differentiation from non-AD samples. In the
Phase II portion of this project, we propose to validate our discovered protein biomarkers in a much
larger cohort and translate the new marker panel into a clinically relevant ELISA format for the
intended clinical use of early screening and AD/ADRD progression monitoring. The following aims
will be completed in the Phase II of the proposal: Aim #1: Validate the discovered plasma EV
biomarkers for Alzheimer's disease and refine the panel. Aim #2: Carry out analytical evaluation and
validate the EXrich instrument for automated EV enrichment. Aim #3: Adapt the developed plasma
EV biomarker panel into a clinically relevant ELISA format. By the completion of this project, a
minimally invasive plasma-based early Alzheimer's disease detection assay will be validated that can
overcome the limitations of current approaches, and thus could have an enormous public health
impact and market potential.
