Blood-based diagnostics for Alzheimer disease have advanced in recent years, with the US Food and Drug Administration clearing a test and multiple companies developing assays based on amyloid plaques or phosphorylated tau.1 Now, Navneet Dogra, PhD, and colleagues are pursuing a different target: the RNA trajectory from DNA to protein. Dogra’s work hypothesized that RNA changes might precede pathology, allowing detection of dementia 1 step ahead of the pathology occurring.
The strategy began with a blood draw, followed by isolation of extracellular vesicles and particles (EVPs), and then RNA extraction.2 Dogra said he ultimately aimed to develop a polymerase chain reaction (PCR) assay targeting a defined set of RNAs that changed consistently with aging, neurodegeneration, or Alzheimer disease. These test types are familiar, with PCR tests being widely used during COVID-19. In principle, the full process from blood sample to result could take 4 to 5 hours. Dogra described the concept as “taking someone’s blood, extracting a set of extracellular vesicles and particles, and then looking at their RNA and understanding what is going on in the brain.”