US-based researchers have found their blood test measuring amyloid accurately predicts the amount of the protein seen in the brain on brain scans. Their findings are published today (Thursday 1 August 2019) in the scientific journal Neurology.
Amyloid is known to build-up in the brain during Alzheimer’s, creating sticky clumps in the brain that are thought to play a role in disease. There are several different forms of the amyloid protein, some more sticky and harmful than others. Research has shown that people with Alzheimer’s also tend to have more amyloid in their blood than healthy people.
This new study looking at 158 people over the age of 50 presents an approach to measure specific forms of amyloid protein in the blood, suggesting a potential new technique to help diagnose the disease.
Scientists measured the ratios of different forms of amyloid in blood and by combining this with information about the participants age and genetic risk they were able to predict levels of amyloid in the brain as measured by PET scans.
Dr Sara Imarisio, Head of Research from Alzheimer’s Research UK, said:
“Alzheimer’s brain changes begin decades before dementia symptoms start to show and life-changing drugs are likely to be most effective at these early disease stages. An accurate and reliable blood test for Alzheimer’s that can pick up these early changes could revolutionise dementia research and dramatically improve how we select people for early-stage drug trials.
“The results of the study using this blood test are promising but at the moment they cannot tell us if the people with high levels of blood-based amyloid will go on to develop dementia. Improving the accuracy of blood tests has long been a goal for researchers and using additional information about genetic risk to bolster a test like this is an encouraging step forward.
“Now is a critical time to invest in research to realise the possible benefits of a blood test for Alzheimer’s and begin to test potential life-changing drugs earlier.”
Dr James Pickett, Head of Research at Alzheimer’s Society, said: A simple blood test that can detect the early brain changes leading to dementia would really revolutionise the search for new treatments, and our funded research has identified changes in the blood of those in the earliest stages of Alzheimer’s.
‘While the idea of an Alzheimer’s blood test feels like it has been around for decades, advances in technology over the last couple of years mean that it is now a becoming a reality, and fast. This is an incredibly exciting area of progress in dementia research.
‘But it’s important to note this isn’t a blood test for dementia – it tells us that amyloid deposits are in the brain, which are a hallmark of Alzheimer’s disease, but are also found in healthy older people too. This test will speed up dementia research by identifying those at risk of Alzheimer’s who might be suitable for clinical trials aimed at preventing or delaying the development of dementia. In the meantime, we’re eagerly awaiting the results of larger studies to validate this blood test.’