Potassium biomarker may aid early diagnosis

• There is currently no cure for Alzheimer’s disease.
• Researchers are focused on finding new ways to diagnose this type of dementia early.
• Scientists from the University of Melbourne have identified a new blood biomarker for the early diagnosis of Alzheimer’s disease.

Researchers are currently very focused on finding new ways to diagnose early Alzheimer’s disease — a type of dementia for which there is currently no cure.

“We still have no cure for Alzheimer’s disease and rely on early detection and treatment,” Brandon Mahan, PhD, senior lecturer in isotope geochemistry and head of Melbourne Analytical Geochemistry in the School of Geography, Earth and Atmospheric Sciences at the University of Melbourne in Australia explained to Medical News Today.

“This is because if detected and treated early, the later terminal stages of the disease can be protracted out, ideally past the normal life expectancy of the individual. This releases emotional and financial burden on the Alzheimer’s disease-afflicted and their families, as well as on national/global economies,” he explained.

“With the above in mind, we should be aggressively exploring any and all possibilities as regards early detection of Alzheimer’s, focusing our efforts and resources to alleviate this global challenge,” Mahan added.

Mahan is the lead author of a new study recently published in the journal Metallomics that has identified a new blood biomarker for the early diagnosis of Alzheimer’s disease using geochemistry techniques.

For this study, Mahan and his team of analytical geochemists collaborated with a group of neuroscientists from the brain research center The Florey to develop a new blood test for the early diagnosis of Alzheimer’s disease.

To do this, scientists applied and adapted inorganic analytical geochemistry techniques — which is typically used to analyze geological compositions such as rocks and soils — to look for early Alzheimer’s disease biomarkers in the blood.

“Inorganic analytical geochemistry is a general term for research that has its roots in the geosciences, and that is centered around developing, harnessing and applying complex instrumentation (and lab practices) to be able to accurately and robustly determine the chemical composition of materials, whether they are minerals and rocks, water, plant matter etc., and then interpreting these analytical results within a given context,” Mahan explained.

“In most cases, these analyses are done through what is called mass spectrometry, where we completely break down materials into a bunch of ions (charged particles) that we can then manipulate and separate using electric and magnetic fields, and in doing so separate those charged particles from one another based on their mass,” he continued

“From there, using an instrument like that deployed in this study, we can measure the relative amounts of all those different charged particles, all at the same time — this is called multi-collector inductively coupled plasma mass spectrometry or MC-ICP-MS. As a fun fact, the way we break down the materials in the instrument is through using a plasma torch that obliterates the chemical bonds (called atomization) and strips electrons off the atoms (ionization) — this plasma torch burns hotter than the surface of the Sun!”

– Brandon Mahan, PhD

Using 20 blood samples — 10 from people with Alzheimer’s disease and 10 without — Mahan and his team compared levels of potassium isotopes between both groups.

“Basically, the Alzheimer’s disease-afflicted brain seems to flush out potassium that is enriched in the lighter isotope of potassium relative to the normal brain,” Mahan detailed.

“The working hypothesis is that these lighter isotopes of potassium are getting flushed into the bloodstream, in the serum fraction, where we are able to measurably resolve this change in blood serum potassium isotope ratio (caused by Alzheimer’s disease in the brain), again in part thanks to modern state-of-the-art technology that makes this much more possible,” he explained.

“An added benefit to all this is that since this test is based on inorganic mass spectrometry, [that is,] we’re not looking at levels of proteins or other organic matter in the blood, then we don’t have to worry about all the quality-control issues that can arise from the possible breakdown of organic materials during sample storage and transport,” he continued.

“Even though this is a small pilot study, the statistical results already suggest performance in detecting Alzheimer’s disease that is on par with much more mature blood-based biomarkers that are based on organic analyses,” said the researcher.

Mahan told MNT that, for the next steps in their research, the team plans to grow and expand this initial work into a much more comprehensive study with larger populations and to extend this beyond potassium to also look at other metals, such as copper and zinc.

“We now have one of these specialized CRC-MC-ICP-MS instruments here in Melbourne Analytical Geochemistry, putting us on the same campus as The Florey, and doubling our capacity to measure samples — now two instruments including the one at IPGP,” he added. “So, we’re ‘all systems go’ for this expanded work, and are now seeking partners and financial support to enable and accelerate this important and innovative research.”

After reviewing this study, Verna Porter, MD, a board-certified neurologist and director of the Dementia, Alzheimer’s Disease and Neurocognitive Disorders at Pacific Neuroscience Institute in Santa Monica, CA, told MNT she that thought it was exciting as it introduces the potential of potassium isotope compositions as a novel and noninvasive biomarker for Alzheimer’s disease.

“As a doctor treating patients at high risk for Alzheimer’s, any advancement in early detection is very encouraging,” Porter told us. “The possibility of detecting Alzheimer’s earlier through such innovative means could significantly change how we approach treatment and patient care.”

“Early diagnosis is essential because it allows for timely intervention, which can help slow disease progression, improve the patient’s quality of life, and provide families time to prepare,” she explained.

“It also opens the door to utilizing emerging treatments more effectively in the earlier stages of the disease, when they may have the greatest impact. Diagnosing Alzheimer’s early can lead to better care coordination and a more proactive approach to managing symptoms,” Porter added.

For next steps in this research, she also said she would like to see it expanded with larger, more diverse patient populations to confirm the reliability of this novel biomarker.

“Additionally, combining this approach with other established biomarkers, such as beta-amyloid levels and tau protein, would provide a more comprehensive understanding of Alzheimer’s pathology,” she added. “Longitudinal studies to track potassium dysregulation over time would also be valuable in determining its correlation with disease progression.”