They found that people with Alzheimer’s disease, or likely to develop it, had a particular genetic signature which distinguishes them from healthy people. Researchers studied the blood of 100 people, whose average age was 80, as part of the study, published on Tuesday in the journal Molecular Psychiatry.
The group included healthy individuals with and without a family history of Alzheimer’s disease, people with mild cognitive impairment, and those who had been diagnosed with the disease. One (1) in five (5) healthy people in the study tested positive for the genetic signature, putting them at high risk of developing Alzheimer’s disease. Brain imaging conducted as part of the study showed these patients had signs of brain degeneration that is suggestive of Alzheimer’s disease.
Dr. Lesley Cheng, of the University’s biochemistry and molecular biology department, said the blood test had been able to predict Alzheimer’s disease five years before patients in the study were officially diagnosed. The test shows promise in diagnosing Alzheimer’s disease much earlier and with less invasion and cost than current methods, including brain imaging and testing of cerebrospinal fluid. Dr. Cheng said the test had the potential to predict Alzheimer’s disease with 91 per cent accuracy, although bigger trials were needed to reinforce initial findings. She said a fast and cost-effective test to diagnose patients with the disease could provide reassurance for elderly people worried about memory loss that was a normal part of ageing. Those identified as being at high risk could be more closely monitored by doctors and possibly referred for more invasive testing, she said.
With no good long-term treatments available for Alzheimer’s disease, scientists are looking for ways to treat people at an earlier stage when the brain is not so badly damaged. The Melbourne University study’s lead author, Professor Andrew Hill, said a blood test to detect the disease early was crucial to developing such treatments. “It can be used to identify patients [suitable] for clinical drugs, and monitor improvement,” he said.
Dr. Cheng said it was possible that testing for microRNA could detect Alzheimer’s disease earlier than testing for particular proteins that predict the disease. A study published by scientists from King’s College London in 2014 found that testing for ten (10) proteins in the blood predicted the onset of Alzheimer’s disease within a year, in people with memory problems, with 87 per cent accuracy.
REFERENCE: The Age National; 28 OCT 2014; Kate Hagan