Blood test offers early affordable Alzheimer's diagnosis

Scientists in Sweden have made a major breakthrough in the detection of one of the world's biggest killers- Alzheimer's disease - which had previously been notoriously difficult to diagnose in its early stages.

The simple blood test looks to be just as accurate as the current test used to detect the disease, a lumbar puncture that requires a needle to be inserted between vertebra, and which is both painful and dangerous to administer.

The breakthrough was proven through a study of 786 people in their 50s, 60, 70s, and 80s that was carried out by a team led by Dr Nicholas Ashton, from the University of Gothenburg, and published in the Jama Neurology journal.

"This study is a hugely welcome step in the right direction as it shows that blood tests can be just as accurate as more invasive and expensive tests at predicting if someone has features of Alzheimer's disease in their brain," Richard Oakley, an associate director of research and innovation at the Alzheimer's Society, told The Guardian newspaper.

"Furthermore, it suggests results from these tests could be clear enough to not require further follow-up investigations for some people living with Alzheimer's disease,which could speed up the diagnosis pathway significantly in future."

The test, which researchers say can detect Alzheimer's disease 10 to 15 years before a patient develops early symptoms such as forgetfulness, has also been shown to be massively cheaper and much more readily available than lumbar punctures,the study reported.

Oakley said more research will now need to be carried out in different communities around the world,to understand the full efficacy of the blood test and to establish whether it works well on all people who have Alzheimer's disease.

The new test measures the level of a protein called p-tau217 in people's blood. The protein is thought to be a marker for biological changes that happen in the human brain after it develops Alzheimer's disease.

Experts believe people aged 50 and older could soon be offered the test on a regular basis, so those with the disease at an early stage can be offered treatments that slow its progress.

The blood test categorizes people into those who are likely to develop the disease and those at intermediate risk of it, as well as those who are unlikely to develop it.

Alzheimer's disease is a neurodegenerative disease that is the cause of between 60 percent and 70 percent of the world's dementia cases.Around 50 million people globally were living with the disease as of 2020, at an annual cost of around$1 trillion.

Sky News said experts had described the new blood test as revolutionary, and clearly much better than the large range of other tests currently under development.