Much excitement has greeted the publication of a study which appears to be significant step towards developing a blood test that could predict the onset of Alzheimer’s disease.

The study, co-authored by the UK’s Proteome Sciences and King’s College London, identified a set of 10 proteins in the blood having analysed 1,148 individuals. Blood samples from 476 patients with AD, 220 with mild cognitive impairment (MCI)and 452 elderly controls without dementia were tested for 26 proteins previously shown to be associated with AD; a sub-group of 476 individuals across all three groups also had an MRI brain scan.  

The researchers identified 16 of these 26 proteins to be strongly associated with brain shrinkage in either MCI or Alzheimer’s. They then ran a second series of tests and identified a combination of 10 proteins capable of predicting whether individuals with MCI would develop AD within a year, with an accuracy of 87%.

Abdul Hye from King’s and lead author of the study, noted that memory problems are very common, “but the challenge is identifying who is likely to develop dementia”. Now, after “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 AD 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, added that “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”. He added that the next step “will be to validate our findings in further sample sets, to see if we can improve accuracy and reduce the risk of misdiagnosis, and to develop a reliable test suitable to be used by doctors”.

Proteome’s chief operating officer Ian Pike, co-author of the paper, claimed that “by linking the best British academic and commercial research, this landmark study…is a major advance in the development of a simple blood test to identify the disease before clinical symptoms appear”. Equally important, he added, a blood test “will be considerably easier and less expensive than using brain imaging or cerebrospinal spinal fluid”, noting that Proteome is selecting commercial partners to combine the protein biomarkers in a blood test for the global market.

It is, of course, early days, and a number of observers are questioning the value of identifying those at high risk when there is no cure for AD. Nevertheless, UK Secretary of State for Health, Jeremy Hunt, said: “This is welcome research on an issue we’ve 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”.