Scientists at the University of Leeds have developed a new technology that could form the basis of a blood test for Alzheimer’s disease. The new biosensor measures clusters of the hallmark Alzheimer’s protein, amyloid – an early indicator of the disease. The study, funded with help from Alzheimer’s Research UK, is published in the Biosensors and Bioelectronics journal.
Previous research has shown that the level of amyloid in a patient’s bloodstream correlates with the level of amyloid clusters in the brain, which is linked to Alzheimer’s disease onset and severity. The team at the University of Leeds devised a biosensor that can detect very small quantities of amyloid in blood. The biosensor, which is contained on a small gold chip, generates an electrical signal in the presence of amyloid clusters, the strength of which indicates the number of clusters in the sample.
Dr Jo Rushworth, who led the research, said:
“Until now, it has been very difficult to pick out these amyloid clusters from the individual amyloid proteins which are present in healthy people. Our biosensor test uses a new molecular recognition tool that works like a lock that only fits one key; it picks out the ball-shaped amyloid clusters without detecting the individual amyloids.”
The team tested their biosensor on amyloid clusters generated by cells grown in a test tube. The biosensor was able to pick out amyloid clusters similar to those found in human Alzheimer’s disease patients.
Dr Rushworth said:
“We are still at the laboratory stage but, eventually, if we are able to develop this technology, we would be looking to have a mobile phone-sized device where you could do a finger-prick blood test and get an immediate readout telling the doctor the level of these markers in your system.
“At present, if you go to a doctor, they will do a memory test and they may say you have dementia. They may also say that Alzheimer’s is the probable cause, but the only way to definitely find out whether someone had the disease is to examine the brain after death.
“Because we are relying on symptoms, drugs are given to the patient late. What we need is a reliable early test so we can intervene when it is actually going to be of some use. If we were able to diagnose Alzheimer’s disease earlier, the symptoms could be better managed and future treatments could be given at a time when they would have most effect.”
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said:
“A blood test to help diagnose Alzheimer’s could be extremely beneficial for patients, but this new technology is still at an early stage of development and further research will be needed to determine its potential for use in the clinic. Diagnosing diseases like Alzheimer’s is a challenge and a biosensor for markers of the disease could be a helpful addition to the current methods used. The search for diagnostic markers of Alzheimer’s is developing at a rapid pace and investment in research is crucial if we are to explore the true potential of this kind of technology for helping people with dementia.”