‘Liquid biopsy’ could identify multiple neurodegenerative disorders

Aethlon and subsidiary Exosome Sciences, both based in San Diego, Calif., announced earlier this month that the companies have isolated blood-borne biomarkers implicated in multiple neurodegenerative diseases.

A statement from the companies noted that exosomes from the central nervous system have been primarily associated with cerebrospinal fluid, but research led by the partnership has identified exosomes of brain-specific glycoprotein A2B5 and S100B, beta amyloid and tau in peripheral circulation. These exosomes cross the blood brain barrier into the bloodstream and could be a target for diagnostic testing of neurological disease.

“This advancement represents a new paradigm for brain injuries,” said Exosome Sciences chief scientific officer, Douglas Taylor, MD, in a statement. “In addition to providing definitive diagnosis, the proteomic and transcriptomic characterization of exosomes isolated specifically from the brain will provide a window into the molecular mechanisms underlying acute and chronic brain injuries."

Major targets for blood testing of these exosomes include Alzheimer’s disease, traumatic brain injury and chronic traumatic encephalopathy (CTE), a progressive disease that is associated with trauma to the brain from military service and blast-injury and professional athletics such as football. Repetitive head trauma is thought to contribute to onset of the disorder.

Isolated exosomes from peripheral circulation can be unpacked to reveal specific RNA cargoes representing a kind of molecular biopsy for diagnosis, staging of disease and potential therapeutic monitoring.  

“An exosome-based liquid biopsy that could identify the early onset of Alzheimer's disease or CTE in a living person may also unlock the ability to monitor disease progression and set the stage for new therapeutic advances, which could include Aethlon Medical therapeutic devices," CEO of Aethlon Medical and executive chairman of Exosome Sciences Jim Joyce added in the press release.

Future therapeutic devices would focus on a concept called “peripheral sink,” which theorizes that stripping these elements from circulation leads to a reduction in plaque in the brain and the progression of disease. The two companies have filed for a provisional patent for what they are calling “exosome-based diagnostics and extracorporeal therapies.”

These concepts are at their earliest stages and are not currently in clinical use. Further study and regulatory approval is required to validate clinical effectiveness for liquid biopsy and subsequent therapeutics for neurodegenerative disease.