Blood based diagnosis of Alzheimer’s disease

New research has identified novel disease markers that are present in the brain and blood of individuals with AD

Over 450,000 Australians are currently living with dementia, and about 7 in 10 people with dementia have Alzheimer’s disease, or AD. It is a neurodegenerative disorder that attacks brain cells, affecting brain function, memory and behaviour.

In new research published in the Journal of Extracellular Vesicles, Professor Andrew Hill and Dr Lesley Cheng, along with collaborators from the Florey Institute of Neuroscience and Mental Health and the University of Melbourne, have identified novel disease markers that are present in the brain and blood of individuals with AD.

AD is currently diagnosed by measuring memory impairment, and this is at a time when neurodegeneration may already be present.

Hill and Cheng believe that extracellular vesicles may hold the key to an early diagnosis.

“Extracellular vesicles are particles that are secreted by cells,” explains Cheng. “They end up in the bloodstream where they can be collected and isolated. They are packed with protein and genetic cargo, and contain markers that can indicate particular disease states.”

The research team isolated extracellular vesicles from post-mortem brain tissues obtained from healthy individuals and those with AD. The disease markers they found in the brain tissue were also present in the extracellular vesicles isolated in the blood.

“Previous studies have been unable to correlate disease markers with AD-related brain pathology,” says Cheng. “Our research, however, has detected the same markers in the brain and blood.”  

Cheng says that understanding the pre-clinical stages of AD, and the associated markers, will aid the development of a blood based diagnostic test.

“Our discovery may improve our ability to detect AD within a timeframe that allows for early therapeutic intervention, and make a difference to the health and wellbeing of people living with the disease,” she says.