Have researchers found a new diagnostic marker?

By Staff 8 Min Read

  • There are currently about 32 million people globally living with Alzheimer’s disease, with that number expected to grow.
  • Right now it is difficult to diagnose a person with Alzheimer’s disease in the asymptomatic stage before they start showing symptoms.
  • Researchers from the University of Barcelona in Spain have identified a biomarker within the asymptomatic stages of Alzheimer’s disease.

With about 32 million people around the world currently living with Alzheimer’s disease, and that number expected to grow over the next few years, researchers are hard at work trying to find new ways to diagnose the condition as soon as possible.

“One of the major problems in the study of Alzheimer’s, or dementia, in general, is that by the time a patient comes in for a consultation, they already have symptoms, most often with mild cognitive impairment, indicating that dementia has begun to develop,” explained José Antonio del Río, PhD, group leader at the Institute for Bioengineering of Catalonia (IBEC), professor at the Faculty of Biology of the University of Barcelona, member of the Institute of Neurosciences of the University of Barcelona.

“Therefore, it is important to search for markers that, before the appearance of these deficits, can suggest the onset of these processes before they occur,” he told Medical News Today.

Del Río is co-lead author of a study on Alzheimer’s recently published in the journal Biochimica et Biophysica Acta (BBA) – Molecular Basis of Disease.

The marker del Rio refers to is a biomarker — a specific, measurable characteristic of the body that can be used as a sign of normal health processes or disease.

For this new study, del Río and his team have identified a new biomarker within the asymptomatic (symptom-free) stages of Alzheimer’s disease, which is when a person’s brain may have biological changes occurring but does not yet show any cognitive symptoms.

The new biomarker scientists discovered through this study is a molecule called miR-519a-3p, which is a type of microRNA directly linked to the expression of the cellular prion protein.

“These types of molecules are short RNA fragments that play a significant role because their function is to silence the gene expression of certain genes at the mRNA level,” del Río explained to MNT.

“In this way, they control the levels of numerous proteins in different cell types. There is substantial evidence that changes in the expression of these ‘controllers’ can affect processes such as cancer and other pathologies,” he pointed out.

To find out if miR-519a-3p was truly a biomarker for Alzheimer’s disease and not other neurodegenerative diseases, they compared biomarker levels in samples from other tauopathies and Parkinson’s disease.

Scientists reported that this confirmed that the changes in miR-519a-3p were specific to Alzheimer’s disease.

“For neurologists, it is very important to clearly determine the pathology they are facing,” del Río said. “Sometimes there are comorbidity processes where a patient can have more than one pathology at the same time.“

“In our case, what we wanted was to find a biomarker that could be exclusively modified in Alzheimer’s, so it would not be altered in other diseases. This is relevant to generating specific signatures for each disease to achieve a better diagnosis,” he told us.

As there is currently no cure for Alzheimer’s disease, previous research shows early diagnosis of the condition can help with treating symptoms and slowing disease progression.

The researchers of this study believe their biomarker findings may help provide a more accurate diagnosis within the early stages of Alzheimer’s disease.

Del Río said that:

“The results we have obtained have been carried out at the brain level to date. However, this miRNA is also found in blood. Our most important challenge now is to develop the necessary technology to detect small changes that would allow us to determine the early presence of Alzheimer’s in samples routinely obtained in hospitals. In this regard, we do not rule out combining these studies with others we are conducting on different miRNAs to develop this early signature of the disease.”

“Now we need to work with patient cohorts with the support of clinical groups to develop, adapt, and improve the techniques to detect these changes in the asymptomatic stages of the disease,” he added.

After reviewing this study, Karen D. Sullivan, PhD, ABPP, a board-certified neuropsychologist, owner of I CARE FOR YOUR BRAIN, and Reid Healthcare Transformation Fellow at FirstHealth of the Carolinas in Pinehurst, NC, told MNT she is always hopeful to see new research that may help us diagnose Alzheimer’s disease in the earliest stage possible.

“Time is brain — the longer someone waits for an accurate dementia diagnosis, the more time is wasted to personalize therapies with the goal of stabilization,” Sullivan explained.

“We’ve known for some time that the physiological disease process in Alzheimer’s disease is happening decades before the clinical symptoms of trouble with new learning and short-term memory are revealed,“ she told us.

“That’s where we all want the advances to happen — as early as possible before we lose networks of brain cells and the damage becomes irreversible,” noted Sullivan.

MNT also spoke with Manisha Parulekar, FACP, AGSF, CMD, director of the Division of Geriatrics and co-director of the Center for Memory Loss and Brain Health at Hackensack University Medical Center in New Jersey, also not involved in this study.

Parulekar agreed it is important to have more tools to diagnose Alzheimer’s at an early, asymptomatic stage.

“This will allow early interventions and support for patients and care providers,” she told us. We are continuing to look for effective treatments for Alzheimer’s. Identification of various biomarkers can potentially help understand the pathophysiology, which will help us in identifying effective treatments.”

“It is exciting to see various biomarkers to help assist with early diagnosis — this will allow us to continue making progress in getting an effective treatment for this devastating disease that affects millions of people,” the expert added.

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