New Blood Test to Detect Alzheimer’s Disease Before Clinical Symptoms Develop

Alzheimer’s disease (AD) is the most common form of dementia, accounting for 60-70% of cases worldwide, totaling over 33 million, according to the World Health Organization. As the global population ages, the incidence of AD is increasing, with the number of dementia sufferers expected to double every 20 years. The economic impact of dementia is also significant, with costs projected to reach USD 2.8 trillion by 2030. Currently, there is no cure for AD, and it is typically diagnosed through a combination of medical history, neurological examinations, and assessments of cognitive, functional, and behavioral capacities, alongside brain imaging and protein analysis of cerebrospinal fluid or blood. Early diagnosis can lead to earlier interventions, such as lifestyle adjustments and medications that may slow disease progression and allow individuals and families more time to mitigate the social, emotional, and financial impacts of dementia. Early diagnosis also increases eligibility for clinical trials, potentially offering additional medical benefits. Now, new research has identified a unique method for early diagnosis of AD by analyzing biomarkers in blood, which could reduce the impacts of dementia.

A group of analytical geochemists at The University of Melbourne (Victoria, Australia) are collaborating with neuroscientists to develop a blood test for earlier diagnosis of AD. In a world first, the researchers have applied techniques from inorganic analytical geochemistry, initially developed for cosmochemistry—the study of the origin and development of celestial bodies—to identify early AD biomarkers in human blood serum. They analyzed potassium isotope levels in 20 blood serum samples—10 from healthy individuals and 10 from AD patients enrolled in the Australian Imaging, Biomarker and Lifestyle study and biobank.

Image: The researchers used state-of the-art equipment for isotope ratio mass spectrometry (Photo courtesy of The University of Melbourne)

Their findings revealed distinguishable differences in the levels of potassium isotopes between healthy and AD individuals, allowing them to reliably identify those with AD. As reported in the study published in Metallomics, this minimally invasive test evaluates the relative levels of potassium isotopes in blood serum, demonstrating potential for diagnosing AD before cognitive symptoms emerge. This approach not only provides a way to act earlier to reduce the effects of the disease but also offers a scalable solution. Unlike protein-based diagnostics, which can degrade over time, this method avoids issues of sample stability by focusing on an inorganic biomarker.

“Our blood test successfully identified AD and shows diagnostic power that could rival leading blood tests currently used in clinical diagnosis,” said study co-author Professor Ashley Bush who sees promise in the results from the small pilot study. “Significant further work is required to determine the ultimate utility of this promising technique.”

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