A blood test for Alzheimer's might be just two years away. 
 
 Abdul Hye at King's College London and his colleagues have identified 10 proteins in blood that can predict who will develop Alzheimer's disease a year after having mild memory problems. Its accuracy is almost 90 per cent. That could prove a huge boost for researchers seeking treatments. 
 
 So far, trials of Alzheimer's drugs are thought to have failed because they have been given too late in the course of the disease to halt progression. The new blood test will initially be used to identify those people with mild cognitive impairment who are likely to get Alzheimer's disease and so might be good candidates for clinical trials to find drugs that halt disease progression. 
 
 "Having a blood test is a really big step forward," says team member Ian Pike of Proteome Sciences in Cobham, UK. "The most important thing we can do is get the correct patients into clinical trials so we can tell, for example, whether it is a drug that is slowing the progression of the disease or the fact that we just happen to have a group of patients who have a slow progressing form of the disease." 
 
 Feared diagnosis 
 
 "This [blood test] is a technical tour de force," says Eric Karran, director of research at the Alzheimer's Research UK charity. However, he remains cautious about its use beyond clinical research. For every 10 people who take the test, one will get an incorrect result. "Alzheimer's is the most feared diagnosis, so we have to be careful, particularly in the absence of any treatment," he says. 
 
 The researchers are also calling for caution until larger trials have taken place. "Lots of blood tests said to be the next big thing haven't come to anything – we have to replicate these results with larger numbers," says team member Simon Lovestone now at the University of Oxford. 
 
 Hye and his colleagues analysed 26 proteins in blood from 1,148 people, including 476 people with Alzheimer's, 220 with mild cognitive impairment and 452 elderly healthy controls. Almost half of the participants in each group also had an MRI brain scan. 
 
 Further clues 
 
 The team identified 16 proteins that were strongly associated with brain shrinkage in people with mild cognitive impairment or Alzheimer's. A further analysis showed that 10 of these proteins could predict whether individuals with mild cognitive impairment would develop Alzheimer's within a year. Some of these 10 proteins were associated with tau and amyloid proteins – both found in damaged brain tissue in Alzheimer's. This may yield further clues as to the cause of the disease. 
 
 Other blood tests have claimed to be able to predict Alzheimer's. For example, Howard Federoff at Georgetown University in Washington DC, published a paper in March, describing a test that uses the level of 10 lipids in the blood to identify people who will go on to get Alzheimer's two or three years later with an accuracy of 96 per cent. 
 
 However, the UK team says it is confident that the newer test will be easier to translate into clinical practice because it uses simple technology to measure proteins in the blood, whereas lipid measurement is more challenging. 
 
 As with any test for Alzheimer's – a disease for which there is no cure – there is always the question of whether people would want to know the result. Lovestone thinks some will. "I have people with memory problems come to me and want to know what's happened to them. I have to say 'see me in a year and I'll tell you whether you've got dementia or not' – and that's grim. So there are people who want to know." 
 
 "I think it will give patients and family members a degree of clarity of what the future may hold," Pike says, "which allows you to plan for the inevitable." 
 
 Journal reference: Alzheimer's & Dementia, DOI: 10.1016/j.jalz.2014.05.1749 
 
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 British scientists have made a "major step forward" in developing a blood test to predict the onset of Alzheimer's disease. 
 
 Research in more than 1,000 people has identified a set of proteins in the blood which can predict the start of the dementia with 87% accuracy. 
 
 The findings, published in the journal Alzheimer's & Dementia, will be used to improve trials for new dementia drugs. 
 
 Experts warned that the test was not yet ready for doctors' surgeries. 
 
 Research into treatments for Alzheimer's disease has been plagued by failure. Between 2002 and 2012, 99.6% of trials aimed at preventing or reversing the disease flopped. 
 
 Doctors believe the failure is down to treating patients when it is already too late, since symptoms appear around a decade after the start of the disease. 
 
 Identifying patients earlier is one of the priorities for dementia research. 
 
 Dementia across the globe 44 million globally have dementia 
 
 135 million will have the disease in 2050 
 
 By then 71% will be poor and middle income 
 
 $600bn global cost of dementia 
 
 In the UK, cancer research gets 8x as much funding as dementia Source: Alzheimer's Society 
 
 Blood test 
 
 The research group, which combines university and industry scientists, looked for differences in the blood of 452 healthy people, 220 with mild cognitive impairment and 476 with Alzheimer's disease. 
 
 They were able to tell with 87% accuracy which patients with mild cognitive impairment would go on to develop Alzheimer's disease in the next year. 
 
 "We want to be able to identify people to enter clinical trials earlier than they currently do and that's really what we've been aiming at," said lead researcher Prof Simon Lovestone from the University of Oxford. 
 
 Media caption Prof Simon Lovestone discusses the detection of Alzheimer's 
 
 However, he said it may find a place in doctors' surgeries in the future. 
 
 "As long as there is no treatment one can question the value of a test, but people come to the clinic because they want to know what's happening to them and I currently can't tell them." 
 
 He said he was forced to tell patients to come back in a year and see if their memory problems were any worse. 
 
 Prof Lovestone added: "That's grim, it's horrible, you can only imagine what that's like for patients. 
 
 "Although I have some real reservations about doing a test, all I can say is there are some people who come to clinics asking precisely that question." 
 
 Image copyright SPL Image caption Loss of tissue in a demented brain compared with a healthy one 
 
 Dr Ian Pike, chief operating officer at Proteome Sciences, said: "Having a protein test is really a major step forwards. 
 
 "[It] will take several years and need many more patients before we can be certain these tests are suitable for routine clinical use, that process can start fairly quickly now." 
 
 Dr Eric Karran, director of research at Alzheimer's Research UK, described the study as a "technical tour de force". 
 
 However, he warned the current accuracy levels risked telling healthy people they were on course to develop Alzheimer's which may lead to anxiety and depression. 
 
 It is unlikely that the test would be used in isolation if it eventually makes its way into clinics. A positive result could be backed up by brain scans or testing spinal fluid for signs of Alzheimer's. 
 
 However, Dr Karran did argue this was a step towards making Alzheimer's a preventable disease. 
 
 "I think it does, but not immediately. 
 
 "This gives a better way to identify people who will progress to Alzheimer's disease, people who can be entered into clinical trials earlier, I think that will increase the potential of a positive drug effect and thereby I think we will get to a therapy, which will be an absolute breakthrough if we can get there. 
 
 "It's not a simple journey. We all wish it was."
– Alzheimer's may be well on its way to being a detectable disease by way of a blood test. The BBC reports on the "major step forward": Researchers at King's College London studied differences in the blood of 1,148 people—476 with Alzheimer's, 220 with mild cognitive impairment, and 452 healthy controls. They zeroed in on blood proteins and out of 26, found 10 that were able to predict which patients suffering from mild cognitive impairment would develop Alzheimer's within the year, New Scientist explains. The predictions were 87% accurate. These proteins could help doctors develop a blood test that will identify future sufferers more quickly, with doctors indicating that a current hurdle to treating the disease is that symptoms can take a full decade to appear. Still, there is no cure. But as researcher Simon Lovestone points out, he has no option but to tell patients who are worried about what might be happening to them to come back in a year to see if things are worse. "That's grim," he says. Still, he downplays his findings, published in Alzheimer's & Dementia, a bit: "Lots of blood tests said to be the next big thing haven't come to anything—we have to replicate these results with larger numbers." (March saw the announcement of another potential Alzheimer's blood test that makes use of blood fats.)