Researchers at King’s College London and co-funded by Alzheimer’s Research UK have announced a panel of 10 proteins that could form a blood test to predict those most likely to develop Alzheimer’s. The research is the result of an international collaboration involving Proteome Sciences and funded by Alzheimer’s Research UK, the MRC and NIHR Maudsley Biomedical Research Centre. The study is published on 8 July in the journal Alzheimer’s and Dementia.
There is currently a large focus in the research community on developing simple and accurate tests that could detect Alzheimer’s early or predict who may go on to develop the disease. Alzheimer’s changes are known to start in the brain 10 to 15 years before symptoms show and so detecting the disease early could give new treatments the best chance of success.
Simon Lovestone, now at Oxford University, and his team studied blood samples from 1,148 volunteers. Of the participants, 452 did not have dementia, 476 had Alzheimer’s and 220 had mild cognitive impairment (MCI). Mild cognitive impairment is a term used to describe early memory and thinking problems, which do not necessarily lead onto Alzheimer’s, but can put people at a higher risk of the disease. Some of the volunteers also had brain scans to look for tell-tale signs of Alzheimer’s in the brain.
The researchers analysed blood samples from the volunteers for 26 proteins previously linked to Alzheimer’s disease. They found that several of these proteins associated with brain shrinkage on brain scans in people with mild cognitive impairment and Alzheimer’s. Taking their research a step further, the team investigated whether any of the proteins could predict the progression from mild cognitive impairment to Alzheimer’s. They discovered a panel of 10 proteins that were able to predict which volunteers with mild cognitive impairment would go on to develop Alzheimer’s within a year.
Abdul Hye, lead author of the study from the Institute of Psychiatry at King’s College London, says: “Memory problems are very common, but the challenge is identifying who is likely to develop dementia. There are thousands of proteins in the blood, and this study is the culmination of many years’ work identifying which ones are clinically relevant. We now have a set of 10 proteins that can predict whether someone with early symptoms of memory loss, or mild cognitive impairment, will develop Alzheimer’s disease within a year, with a high level of accuracy.”
Simon Lovestone, senior author of the study from the University of Oxford, who led the work whilst at King’s, says: “Alzheimer’s begins to affect the brain many years before patients are diagnosed with the disease. Many of our drug trials fail because by the time patients are given the drugs, the brain has already been too severely affected. A simple blood test could help us identify patients at a much earlier stage to take part in new trials and hopefully develop treatments which could prevent the progression of the disease. Our next step will be to test our findings in even larger sample sets, to further improve accuracy and reduce the risk of misdiagnosis, before we can develop a reliable test suitable to be used by doctors.”
Eric Karran, director of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, says:
“As the onset of Alzheimer’s is often slow and subtle, a blood test to identify those at high risk of the disease at an early stage would be of real value. Detecting the first signs of Alzheimer’s could improve clinical trials for new treatments and help those already concerned about their memory, but we are not currently in a position to use such a test to screen the general population.
“It is promising to see research taking us closer to mapping the first changes in Alzheimer’s, and the team has pooled data from different studies worldwide to bolster their findings. Many people with mild cognitive impairment will not go on to develop Alzheimer’s, but the proteins identified in this panel could help researchers to understand the biology driving the disease in those who do. However, with the risk of misdiagnosis from this panel still high, we would need to see such a test well validated and repeated before it could be used in the clinic.
“With an ageing population, and age the biggest risk factor for Alzheimer’s, we are expecting rising numbers of people to be affected over the coming years. It is important to develop new ways to intervene early in the disease to help people maintain their quality of life for as long as possible.”