Blood test predicts genetic Alzheimer’s disease progression
An international collaboration from Australia, UK, USA and Europe has shown that a blood test can predict inherited Alzheimer’s disease at least a decade before clinical symptoms are evident.
The Dominantly Inherited Alzheimer’s Network (DIAN) study provides hope that the test could become part of routine medical check-ups, which would provide a cheap and efficient early warning system for Alzheimer’s disease in the general community.
The Australian arm of the study was a joint project between the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Edith Cowan University in Western Australia and NeuRA in Sydney.
Professor Colin Masters AO from the Florey Institute said, “The blood test accurately predicted when members of a family with inherited Alzheimer’s disease would begin to show symptoms. Inherited Alzheimer’s is rare genetic disease. Using this very defined patient population we were able to identify affected family members over a decade before they began to show cognitive impairments.”
There is hope that the blood test will eventually be useful for a wider range of people who may be at risk of the common form of older-onset Alzheimer’s disease known as “sporadic”, as well as those with the genetic version.
Neurofilament light, or NfL, is a crucial building block of brain cells. When these cells start to die in Alzheimer’s disease, traumatic brain injury or other neurodegenerative diseases, this building block is released into the blood stream.
The blood test accurately predicted when members of a family with inherited Alzheimer’s disease would begin to show symptoms. Inherited Alzheimer’s is rare genetic disease. Using this very defined patient population we were able to identify affected family members over a decade before they began to show cognitive impairments.
- Prof Colin Masters
The data showed that when patients converted from pre-symptomatic disease to having clear cognitive and memory decline, NfL built up in the blood at the fastest rate.
“NfL levels rise whenever the brain is damaged, and as Alzheimer’s disease affects 30 per cent of people over the age of 80, we hope that NfL will become part of a GP’s standard battery, like annual cholesterol testing. We would send patients off for more specific Alzheimer’s tests if the results come back showing a cause for concern.” says Professor Masters.
If a patient is identified as being in the early phase of the disease, they could be referred to a pharmacological clinical trial, make diet and lifestyle modifications and be placed on existing medications in the hope of slowing down disease progression.
Next steps for the test include replicating the results in sporadic Alzheimer’s disease patients, who are older and often have other health issues. The Australian Imaging Biomarker and Lifestyle (AIBL) patient samples will be used to validate these test results.
The study, Serum neurofilament dynamics predicts neurodegeneration and clinical progression in pre-symptomatic Alzheimer’s Disease, was published in Nature Medicine, and was funded by European, American and Australian funding agencies including the National Health and Medical Research Council.
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