Tau-PET: A New and Improved Method for Predicting Cognitive Decline

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Tau-PET: A New and Improved Method for Predicting Cognitive Decline

Tau-PET: A New and Improved Method for Predicting Cognitive Decline.

A team from UNIGE-HUG has presented a breakthrough in imaging technology for identifying tau proteins in the brain, a predictive factor for cognitive decline associated with Alzheimer’s disease.

Alzheimer’s is a common neurodegenerative disorder leading to gradual deterioration in memory and independence.

Tau-PET: A New and Improved Method for Predicting Cognitive Decline

Using 18F-Flortaucipir PET, researchers imaged tau in Alzheimer’s patients. The image displays a typical pattern of tau accumulation obtained by comparing tau loads between Alzheimer’s patients and a healthy control group. The color scale from blue to white indicates increasing tau load, with pink-white areas representing the highest accumulation. Source: UNIGE

The hallmark of this disease is the accumulation of harmful proteins in the brain, notably amyloid plaques and tau tangles. Given that these pathological changes evolve silently over decades, early diagnosis is crucial for prompt intervention during the disease progression.

Researchers from the University of Geneva (UNIGE) and Geneva University Hospitals (HUG) have found that tau PET (a novel imaging technique visualizing tau proteins) is more adept at predicting cognitive decline in patients compared to conventional imaging methods.

These findings, published in the journal “Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association,” support the rapid integration of tau PET into clinical routine, offering early and personalized solutions for patients.

Currently, one of the primary diagnostic tools for Alzheimer’s is Positron Emission Tomography (PET), an imaging technique using tracer injections to observe specific pathological processes in the brain.

“PET is an imaging technique that involves injecting tracers to observe specific pathological processes in the brain,” explained Valentina Garibotto, Associate Professor of Radiology and Medical Informatics at the University of Geneva Medical School and Head Physician in the Nuclear Medicine and Molecular Imaging Department at HUG, who led the study.

“These tracers are designed to bind to the molecules in the body that we want to detect, making them visible in PET scans,” Garibotto clarified. “Specific tracers for amyloid plaques have existed for twenty years, and tracers for monitoring glucose metabolism, indicating the brain’s ability to use energy resources correctly, have also long existed. However, Alzheimer’s is incredibly complex, and these two techniques are insufficient to provide all the answers.”

Comparison of Imaging Techniques:

Flortaucipir is a radioactive tracer that binds to tau proteins. It was developed by a pharmaceutical company and received approval from the U.S. Food and Drug Administration (FDA) in 2020.

It can detect the accumulation and distribution of tau proteins in the brain, accurately assessing their role in clinical manifestations of the disease.

Scientists from the University of Geneva and Harvard University aimed to determine which imaging modality (amyloid PET, glucose metabolism PET, or tau PET) best predicted future cognitive decline caused by Alzheimer’s. Around 90 participants were recruited from HUG Memory Center.

“Our results show that while various PET measures are associated with the presence of cognitive symptoms, confirming their strong role as indicators of Alzheimer’s, tau PET measures are the best predictors of the speed of cognitive decline, even in individuals with very mild symptoms,” summarized Cecilia Boccalini, the lead author of the study and a doctoral student in Garibotto’s team.

Detecting Individual Differences:

Amyloid plaques don’t necessarily correlate with cognitive or memory loss. However, tau’s presence is closely linked to clinical symptoms.

Its presence is a key factor determining whether a patient’s condition remains stable or deteriorates rapidly.

Visualizing tau through imaging has been challenging due to its low concentration and complex structure.

“This breakthrough is crucial for better Alzheimer’s treatment. Recent progress has been made in drugs targeting amyloid plaques,” and new drugs targeting tau proteins hold promise as well, noted Valentina Garibotto. “By detecting pathology before further brain damage occurs and adopting new treatment methods, we hope to have a greater impact on patients’ future and quality of life. Likewise, we’re beginning to map the distribution of tau to understand how its presence in different brain regions affects symptoms.”

In fact, it has become evident that the etiology and different stages of this disease are far less uniform than previously thought, emphasizing the need for a better understanding of individual susceptibility to the same phenomena.

These findings strongly advocate for the inclusion of tau PET in routine clinical assessment, facilitating individual prognosis evaluation and selection of the most suitable treatment strategies for each patient.