A simple blood test that could diagnose early onset Alzheimer’s disease has been developed by University of Melbourne researchers.
The research team had already identified what changes occurred in patients’ brains up to two decades before they showed signs of dementia through expensive brain imaging tests.
But the new blood test could predict the changes and the person’s risk of developing Alzheimer’s much earlier.
Professor Andrew Hill said his team looked at the genes known as microRNA in small packages called exosomes, of people with Alzheimer’s disease and compared them with those who did not.
“The first part of the study we sequenced 50 people – 23 had Alzhimer’s and 23 were controls and then there were another few that were in an in-between stage,” Professor Hill said.
He said researchers then identified 16 out of 1400 microRNA that had changed in Alzheimer’s patients.
“Then we performed a second study where we didn’t know the diagnosis of the participants.”
He said looking at the same 16 exosome microRNAs in the second group of patients, the researchers were able to detect the disease with 91 per cent accuracy.
“Those participants had brain imaging performed and we could actually tell which ones had Alzheimer’s and which ones didn’t.”
Professor Hill said being able to detect Alzheimer’s early would give people a better chance at slowing down the onset of the disease.
“To develop and use new therapies we need to identify people at an early stage because Alzheimer’s is a degenerative disease so once the damage has started occurring you can’t go back from that,” he said.
“Other research has shown lifestyle changes can help reduce the risk of Alzheimer’s, so people can start doing things like increasing physical activity, cognitive stimulation, social engagement and eating a healthy diet.”
Alzheimer’s disease is the most common form of dementia in Australia, according to Alzheimer’s Australia.
Up to 70 per cent of the 332,000 Australians living with dementia suffer from the disease.
Professor Hill said the research could also help drug companies develop better treatments.
“We’re hoping that this test might also help in drug trials and looking at how the drug trials are actually working,” he said.
“Alzheimer’s is a degenerative disease that takes up to two decades to go through the degeneration process, so identifying people early is going to be important for stopping the damage to the brain.”
“Currently there is a number of tests, including a brain imaging test that can help diagnose the disease, plus a lot of cognitive testing to look for early signs of memory loss,” he said.
“So we’re hoping that our test is going to bridge the gap of perhaps a pre-screen for those who might need to go and have some more brain imaging done.”
Test could be three years away
Professor Hill said the technique of identifying the microRNA had been developed over two to three years, and a blood test could be rolled out in the next three to five years.
The initial results need be validated in a wider sample, before the test would be available.
“Our next aim is to increase the number of samples that we look at to further refine the panel of 16 exosomal microRNAs,” he said.
“So we’re looking to move this forward by analysing more samples and also looking at whether these microRNAs are involved in the disease process.
Future research would also look at whether the microRNAs were involved in the progress of the Alzheimer’s disease.
“That’s something that we haven’t been able to show so far, we just are basically looking for a marker of Alzheimer’s disease using a simple laboratory test that measures the number of these microRNAs in the blood samples,” he said.
“So future work is aimed at trying to id whether these microRNAs are actually involved in the disease process.”
Professor Hill said researchers also hoped to expand their research to see if a similar test could be developed for other degenerative diseases like Parkinson’s.