Computer graphic of a vertical (coronal) slice through the brain of an Alzheimer patient / Science Photo Library

Blood test can predict whether a person with mild cognitive impairment will develop the disease within a year

Scientists in Britain have developed a new blood test that can help predict the onset of Alzheimer’s disease.

Ten years of research has led to scientists at King’s College and the University of Oxford identifying a set of 10 proteins in the blood that can predict the onset of Alzheimer’s in the next 12 months for people experiencing memory problems, with 87 per cent accuracy.

The blood test, which is expected to cost between £100 and £300, has been hailed as a “major step forward” by scientists and could be available within two years.

Previous trials for Alzheimer’s drugs have had a high rate of failure, and experts have warned that the new blood test is not yet ready for use within doctor’s surgeries.

It is believed that the rate of failure is down to treating patients when the disease has become too far advanced, as it can take around 10 years for symptoms of Alzheimer’s to show.

An estimated 496,000 people currently suffer from Alzheimer’s in the UK. There are currently no drug treatments that can provide a cure, there are only medicines that can help to improve symptoms or temporarily slow down the progression of the disease in some people, according to the Alzheimer’s Society.

The research used blood samples from over 1,000 people and MRI scans from 473 people, with researchers identifying 16 proteins that were implicated in the development of the disease and could be used as markers for dementia, even before the full symptoms develop.

Lead researcher Professor Simon Lovestone from the University of Oxford said that researchers have been aiming at being able to “identify people to enter clinical trials earlier than they currently do”.

He told the Telegraph that it is unlikely that GPs would use the test until a treatment is available: “As long as there are no treatments one can question the value of using a test in that sort of setting.

“At the moment people come to me with memory loss and ask if they will get Alzheimer’s and I have to tell them to come back in a year. That is grim. It’s horrible.

“So although I would have some reservations about doing a test, some people who come to clinics do want to know,” he added.

Dr James Pickett, head of research at the Alzheimer’s Society said that finding a way to detect dementia before symptoms develop would “revolutionise” research into the condition.

But the research “does not mean that a blood test for dementia is just around the corner”, he warned.

These ten proteins can predict conversion to dementia with less than 90 per cent accuracy, meaning one in ten people would get an incorrect result. Therefore, accuracy would need to be improved before it could be a useful diagnostic test Only through further research will we find answers to the biggest questions around dementia, so we will watch the progress of this study with interest.'

Secretary of State for Health, Jeremy Hunt, said this is "welcome research" on an issue the Government has made a national priority.

“Developing tests and biomarkers will be important steps forward in the global fight against dementia as we search for a cure," he added.