A new test which could detect if a person will develop dementia within three years has been called a “major step forward”.US scientists have said the discovery of changes in the blood may signify the earliest stages of Alzheimer’s disease – a condition which affects 35 million people worldwide.
For the first time, they have shown differences in blood biomarkers between those with Alzheimer’s before symptoms occur and those who will not develop it.
And the scientists claim the test using 10 identified molecules has a 90% accuracy rate.
The research may help treatment strategies at an earlier stage – when therapy would be more effective at slowing or preventing onset of symptoms.
Researchers from Georgetown University Medical Centre examined 525 participants aged 70 and over and monitored them for five years.
Halfway through the study, the authors analysed blood samples from 53 patients who already had one of the conditions and compared them with those from 53 “cognitively normal” people.
They found the biomarkers could predict with 90% accuracy whether participants went on to develop mild cognitive impairment (MCI) or Alzheimer’s.
One of the study’s authors, Professor Howard Federoff, said: “We consider our results a major step toward the commercialisation of a preclinical disease biomarker test that could be useful for large-scale screening to identify at-risk individuals.”
At the moment, the test is only going to be used for research.
Dr Simon Ridley from the charity Alzheimer’s Research UK said: “Alzheimer’s disease begins to develop long before symptoms such as memory loss appear.
“But detecting the disease at this pre-symptomatic stage has so far proved difficult.
“More work is needed to confirm these findings, but a blood test to identify people at risk of Alzheimer’s would be a real step forward for research.”