Blood test might diagnose Alzheimer’s much earlier

"This test could ease concerns for patients experiencing normal memory problems due to natural aging," says Lesley Cheng. "Those identified as high risk could then be monitored by their doctor." (Credit: Tim Caynes/Flickr)

A simple blood test might diagnose early onset Alzheimer’s disease with increased accuracy and much sooner than currently possible.

Previous research has found that changes in the brain occur two decades before patients show signs of dementia. These changes can be detected through expensive brain imaging procedures.


The blood test has the potential to improve prediction of Alzheimer’s disease to 91 percent accuracy. But because it’s a progressive disease, more testing is needed in a larger population over several years.

In an initial trial group using the blood test, one in five healthy participants with no memory complaints tested positive.

On further medical investigation using brain-imaging techniques, these patients showed signs of degeneration in the brain resembling Alzheimer’s disease features.

The findings are published in the journal Molecular Psychiatry.

The blood test would significantly advance efforts to find new treatments for the degenerative disease and could lead to better preventative measures prior to diagnoses, says lead researcher Andrew Hill from the biochemistry and molecular biology department and Bio21 Institute at the University of Melbourne.

“This blood test would be crucial to the development of therapeutic and preventative drugs for Alzheimer’s disease. It can be used to identify patients for clinical drugs and monitoring improvement on treatment.”

Genetic bubbles

The blood test’s high accuracy comes from its ability to harvest protected bubbles of genetic material, called microRNA, found circulating in the bloodstream. People with Alzheimer’s contain a certain set of microRNA that distinguishes them from healthy people.

The test is an accessible method for patients to accurately predict their susceptibility to Alzheimer’s, says Lesley Cheng from the biochemistry, molecular, and cell biology department and Bio21 Institute.

“This test provides the possibility of early detection of Alzheimer’s disease by using a simple blood test which has been designed to also be cost-effective. Furthermore, it is highly accessible for patients and physicians compared to organizing a brain scan or undergoing a neuropsychological test.

“Patients with a family history of Alzheimer’s disease or those with memory concerns could be tested during a standard health check at a medical clinic.

“This test could ease concerns for patients experiencing normal memory problems due to natural aging. Those identified as high risk could then be monitored by their doctor.”

The research was conducted in collaboration with The Florey Institute of Neuroscience and Mental Health, the CSIRO, and Austin Health and Australian Imaging Biomarker and Lifestyle study of Aging.

Source: University of Melbourne