Imagine a world where a straightforward blood test might predict your risk of Alzheimer’s disease long before any memory issues arise.
A recent study suggests that this possibility may soon be within reach thanks to advancements in medical research.
This innovative test targets a biomarker known as ‘p-tau217’, which could alert medical professionals to the risk of Alzheimer’s five to ten years before a person starts experiencing symptoms.
While the prospect of such early detection might evoke a mix of emotions, it could prove invaluable in accelerating the development of new drugs by facilitating the recruitment of individuals with a higher predisposition for the disease into clinical trials for Alzheimer’s treatments and preventive measures.
The research team, led by Reisa Sperling at the Mass General Brigham Neuroscience Institute in the United States, has indicated that the p-tau217 test has mostly been employed previously on individuals exhibiting symptoms.
“Right now it’s really being utilised in people who already have symptoms of Alzheimer’s disease and are thought to have cognitive impairment due to Alzheimer’s disease,” she said.
“In this study, we are looking at people who do not yet have symptoms of Alzheimer’s disease.”
How does the Alzheimer’s test work?
The results, presented at the Alzheimer’s Association International Conference in London, showed similar patterns in those at risk of developing Alzheimer’s.
It found that symptom-free older adults who harboured very high levels of p-tau217 in the blood test had a 38 per cent risk of developing cognitive impairment over five years. That risk grew to 78 per cent by 10 years.
“We also found that people who have a very low level of this blood test, p-tau217, were very unlikely to progress over time and were about the same level as people in general as they age over a 10-year period might be at risk for developing impairment,” Sperling said
She said the blood test data offers some new clues. While different intermediate levels of p-tau217 signalled progressive risk, only the very highest level seemed to correlate with other evidence about that tipping point.
Researchers analysed data from 2,684 healthy older adults enrolled in long-running Alzheimer’s studies since 2004, all of whom took the test when they joined. By last year, 478 of them had developed cognitive impairment.
A ‘game changer’
The test can reveal a person’s risk years in advance, information that may be reassuring for some and distressing for others, but it does not offer a cure.
“At this point, it wouldn’t change what I would tell someone to do. I’d still tell them to eat well, sleep well, exercise a lot and stay engaged. But that’s going to change dramatically if the current prevention trials show clinical benefit,” Sperling said.
Already, large clinical trials are testing whether certain drugs could prevent or at least delay the disease.
If any of those works, doctors should have an easy way to tell who should try them — and the blood test can be exactly what they need.
That is why Jessica Langbaum from the Banner Alzheimer’s Institute based in the US, explained the development as a “game changer” for neary 10 people who are diagnosed with Alzheimer’s every year.
“This is really important for people, particularly if we get to a time when there’s one of the treatments that are being tested for Alzheimer’s prevention therapies,” she said.
“If one of those treatments read out having a blood test that can accurately determine who to test and say, yes, this person might be eligible for treatment, I think that’s a real game changer.”
— With additional reporting by the Associated Press