Finger-prick test could screen for early Alzheimer’s

A simple finger-prick tool the size of a credit card could one day change the way GPs screen for Alzheimer’s disease, according to Australian researchers who have spent the last four years creating the groundbreaking device.
 
Developed by Monash University researchers, the first-of-its-kind handheld device is aimed at GPs and uses a quick blood test to detect the hallmark biomarkers in the disease’s early stages and before symptoms progress.
 
It is hoped the tool will one day be rolled out across general practices to streamline diagnoses and offer non-invasive diagnostics.
 
Tests have shown that the technology can detect ultra-low levels of several disease biomarkers in blood, and the researchers behind the project say the next stage is to undertake the clinical validation needed to bring the tool a step closer to reality.
 
Associate Professor Sudha Mokkapati developed the electronic sensor and said she hopes it could one day remove the need for laboratory-based pathology tests, making diagnosis faster and more cost-effective.
 
‘It’s simple to use, low-cost and portable so it could be made widely accessible to GPs to screen patients right at the point-of-care,’ she said.
 
‘Detecting very early disease in large populations could dramatically change the trajectory of this burdening disease for many patients, and shave millions off associated healthcare costs.’
 
But Professor Mark Morgan, Chair of RACGP Expert Committee – Quality Care, warned that the technology must be validated to understand its predictive value.
 
‘The ability to easily and accurately identify pre-symptomatic Alzheimer’s disease is a key step to developing and testing interventions,’ he told newsGP.
 
‘It is important that this validation has impactful cognitive decline as an end point rather than a different biomarker.
 
‘Marketing of this new health technology must not be allowed to get ahead of the science of what it really reveals.’
 
The research comes as dementia rates continue to grow in Australia, and, without a medical breakthrough, the number of diagnoses is expected to increase to more than 812,500 by 2054.
 
With that same trend expected across the globe, similar research to that of Monash University’s is being undertaken internationally.
 
Recent Swedish research used samples from around 800 people across three countries to determine how well a blood-based Alzheimer’s test performed compared to the current available diagnostic tools of positron emission tomography (PET) scans and cerebrospinal fluid (CSF) tests from lumbar punctures.
 
It concluded that a commercially available blood test ‘accurately identified biological Alzheimer’s disease’.
 
Dr Stephanie Daly, a GP with a special interest in dementia, said blood biomarkers in primary care should, at this stage, only be used in people with symptoms, as this is where they have the best chance of accuracy.
 
‘We are probably a long way from screening, especially as we do not have very effective medications that reverse symptoms at this stage, so pre-clinical screening remains controversial,’ she told newsGP.
 
‘Blood-based biomarkers are likely to become available in the next year or two, [until now] they have been solely in the research space.’
 
Dr Daly said the finger-prick test does make diagnosis more accessible, but its rollout must coincide with training for more GPs to identify symptoms, as well as also better wraparound care for those who are diagnosed.
 
‘Certainly, the use of blood-based biomarkers would be an excellent tool for GPs to have access to,’ she said.
 
‘It would enable us to feel more confident in defining the pathology that is leading to someone’s cognitive impairment, which may mean people receive a diagnosis in a more timely way.
 
‘This leads to better outcomes in terms of ability to treat risk factors and also to plan for the future.’
 
Mounting evidence also shows that patients overwhelmingly want early diagnosis rather than being left in the dark about the cognitive symptoms they are experiencing.
 
Benefits of an early diagnosis range from knowing what to expect, being more actively involved in personal decisions, more effective use of treatments, reducing stigma, and being empowered to make choices.
 
Professor Morgan said a correct diagnosis ‘helps enormously’ in GPs being able to provide the correct advice to patients and their families.
 
‘Alongside advances in early diagnosis, it is very important for our health systems to improve the way we look after people with dementia,’ he said.
 
‘There is a need for society to collectively manage the consequences of earlier diagnosis with respect to accessing insurance, employment and driving ability.
 
‘There is a huge stigma and fear around the diagnosis of Alzheimer’s disease that needs to be addressed.’
 
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