Study Points to Simple Blood Test to Predict Alzheimer’s
Researchers link 10 proteins to cognitive impairment
Researchers at King’s College London have identified a set of 10 proteins in the blood that can predict the onset of Alzheimer’s disease (AD), marking a significant step towards developing a blood test for the disease.
The study — published July 7 in Alzheimer’s & Dementia — analyzed more than 1,000 individuals and is the largest of its kind to date.
Approximately 10% of people diagnosed with mild cognitive impairment (MCI) develop dementia within a year, but apart from regular assessments to measure memory decline, there is no accurate way of predicting who will, or won’t, develop dementia.
The researchers used data from three international studies. Blood samples from a total of 1,148 individuals (476 with AD, 220 with MCI, and 452 elderly controls without dementia) were evaluated for 26 proteins previously shown to be associated with AD. A subgroup of 476 individuals across all three groups also underwent a magnetic resonance imaging (MRI) brain scan.
The researchers found that 16 of the 26 proteins were strongly associated with brain shrinkage in either MCI or AD. They then ran a second series of tests to establish which of these proteins could predict the progression from MCI to AD. They identified a combination of 10 proteins capable of predicting whether individuals with MCI would develop AD within 1 year, with an accuracy of 87%.
Lead author Dr. Abdul Hye said: “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.”
Previous studies have shown that positron emission tomography (PET) brain scans and plasma in lumbar fluid can be used to predict the onset of dementia from MCI. However, PET imaging is expensive, and lumbar punctures are invasive.
Currently, there are no effective, long-lasting drug treatments for AD, and it is believed that many new clinical trials fail because drugs are given too late in the disease process. According to the researchers, a blood test could be used to identify patients in the early stages of memory loss for clinical trials to find drugs to halt the progression of the disease.
Source: King’s College London; July 7, 2014.