Experts today warned that cheap blood tests used to detect Alzheimer’s could wrongly indicate people have an incurable disease.
In an effort to revolutionize “shocking” diagnosis rates, thousands of Britons will undergo blood tests to detect signs of the memory-robbing disease.
Scientists hope NHS trials will allow patients to be diagnosed faster and treated sooner. About one in three people living with dementia have not yet received a formal diagnosis and even patients who are told they have the disease may have to wait years to find out.
Experts, however, warned that the innovative tests, which cost around £100, could even provide “false positives”.
In two landmark trials, researchers from Oxford and University College London will use inexpensive tests to detect proteins in the blood linked to the disease and other forms of dementia.
Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and short-term memory loss.
Dr Sebastian Walsh, a dementia risk reduction expert at the University of Cambridge, told MailOnline: “It’s really important to understand who is and isn’t represented in any study.
‘These proposed studies will be carried out in memory clinics.
‘Memory clinics are not the only place where people with dementia (not yet diagnosed) come to health systems, but rather they see a specific group of people referred.
“That’s why it’s important not to generalize beyond the group being considered.”
He added: “A considerable proportion of people who test ‘positive’ in these blood tests, which measure the level of protein, do not have dementia and will never develop it before they die.
“Therefore, it is very important to understand exactly what we are and are not intending to achieve with these blood tests. We need to see more details of the study protocols.”
Other experts have warned that implementing mass testing would cause unnecessary worry and anxiety among those who will never suffer memory or thinking problems.
Meanwhile, Professor Andrew Doig, a biochemistry expert at the University of Manchester, told MailOnline: “What we hope to do is detect and report on things that are going wrong in the brain long before they actually present any symptoms and just problems.” by memory”.
However, in addition to identifying patients who could benefit from new drugs, “there could be false positives,” he added.
‘You could be considered to have hypertension. So if your blood pressure is very high, that doesn’t mean you have hypertension, it just means you’re at high risk.
‘And the same with high cholesterol. And it could mean that you need to take medicine to lower your blood pressure.
“But we have to do the test and hopefully we’ll end up with a treatment that gives the best chance.”
Despite being incurable at the moment, promising new drugs are on the horizon to help treat dementia.
The first of these drugs, lecanemab, was recently approved in the United States and Japan, where treatments using it have already been launched.
A second drug, donanemab, is expected to appear soon, and UK medical authorities are expected to consider approving both in Britain.
But there are also possible serious side effects, such as swelling and bleeding.
Meanwhile, Professor Doig said: “Other drugs that work in a similar way could be better and have fewer side effects.”
“Each drug points the way to others, which would be a real benefit.”
Dr Richard Oakley, associate director of research and innovation at the Alzheimer’s Society, said the trials, which are part-funded by the People’s Postcode Lottery, were a crucial final step in bringing the tests to the clinic.
Professor Paresh Malhotra, an expert in clinical neurology at Imperial College London, told MailOnline that the blood tests “are a huge advance”.
He added: “However, it is vitally important to be aware that they are only informative when combined with a clinical assessment.
“These important trials will help us understand how they can be implemented in practice in the NHS and how they affect the way we diagnose diseases that cause dementia, particularly Alzheimer’s disease, which is the most common cause of dementia.”
Meanwhile, Professor John Hardy, an expert in neurodegenerative diseases at UCL, told MailOnline: ‘In research settings we can very well identify people at high risk of disease and see changes in the blood before the disease appears.
‘TMuch progress has been made but there is still a long way to go. Furthermore, once the scientific questions have been answered, we need to organize dementia care in the NHS so that we can use these tests in routine clinical practice.’
Currently, receiving a formal diagnosis of dementia in the UK is based on mental capacity testing, brain scans or invasive and painful lumbar punctures.
Researchers hope the blood test can speed up the process, allowing patients to receive treatment sooner and delay the attack of the cruel disease.
The trials, which are expected to cost around £10 million, will be carried out across the UK and will be carried out with people who have reported symptoms to their GP and who may be in the early stages of dementia.
In the first, in which 1,100 people will participate, half of the patients will receive the results after three months and the other half after 12 months.
Researchers will then be able to analyze whether getting an earlier diagnosis improves patient care.
UCL neurology expert Professor Jonathan Schott, who will lead the trial, said a simple blood test could “potentially be a game-changer” for those suffering from dementia.
The second trial will study the blood tests of almost 4,000 people to see which are most effective in distinguishing different types of dementia, such as Alzheimer’s, dementia with Lewy bodies and vascular dementia.
Scientists will also study whether the tests can be administered in different ways, such as pricking a finger at home and publishing the tests for analysis.
Around 944,000 people in the UK are thought to be living with dementia, while in the US the figure is around 7 million.
Alzheimer’s affects approximately six in 10 people with dementia.
It is believed to be caused by a buildup of amyloid and tau in the brain, which build up and build up of plaques and tangles that make it difficult for the brain to function properly.
Over time, the brain struggles to cope with this damage and symptoms of dementia develop.
Memory problems, thinking and reasoning difficulties, and language problems are common early symptoms of the condition, which then worsen over time.
Dementia is expected to skyrocket in the coming years, so a cheap screening tool is vital to meeting the challenge.
Analysis by Alzheimer’s Research UK found that 74,261 people died from dementia in 2022, compared to 69,178 the previous year, making it the country’s biggest killer.