Tau imaging with 18F-Flortaucipir PET in Alzheimer’s illness. The determine exhibits a prototypical tau accumulation sample, obtained by evaluating tau load of sufferers with Alzheimer’s illness vs healthy controls. The blue-to-white shade scale signifies extra pronounced tau hundreds, with pink-white areas representing these with the best accumulation. Credit: UNIGE
A group from UNIGE-HUG showcases the worth of imaging in figuring out tau protein within the mind, a predictor of cognitive decline attributable to Alzheimer’s illness.
Alzheimer’s illness is a standard neurodegenerative dysfunction that leads to a gradual decline in reminiscence and independence. It’s characterised by the build-up of dangerous proteins within the mind, particularly amyloid plaques and tau tangles. Due to the silent growth of pathology over a long time, very early analysis is of utmost significance to have the ability to take motion as early as doable within the illness course of.
Researchers from the University of Geneva (UNIGE) and the Geneva University Hospitals (HUG) have proven that tau PET – a novel imaging method for visualizing the tau protein – can predict cognitive decline in sufferers significantly better than the imaging methods usually used.
These outcomes, revealed in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, argue in favor of the fast introduction of tau PET into the scientific routine to offer sufferers with early and individualized options.
Today, one of many fundamental diagnostic instruments for Alzheimer’s illness is positron emission tomography (PET), an imaging method by which tracers are injected to visualise particular pathological processes within the mind. “PET entails injecting sufferers with low-level radioactive tracers that disappear inside a number of hours.
They are designed to bind to the human molecules that we wish to detect, making them seen with the PET tomographs,” explains Valentina Garibotto, Associate Professor within the Department of Radiology and Medical Informatics at UNIGE Faculty of Medicine and Head Physician within the Division of Nuclear Medicine and Molecular Imaging on the HUG, who directed this analysis.
“Specific tracers for amyloid exist for two decades, and tracers to monitor glucose metabolism, which indicates the brain’s ability to use its energy resources correctly, have long existed. However, Alzheimer’s disease is complex and these two techniques are not enough to provide all the answers.”
Comparing imaging methods
Flortaucipir is a radiotracer that binds to the tau protein. It was developed by a pharmaceutical firm and accepted by the Food and Drug Administration (FDA) in 2020. It permits the detection of tau accumulation in addition to its distribution within the mind to exactly assess its function within the scientific manifestation of the illness.
Scientists from the UNIGE and the HUG needed to find out which imaging modality – amyloid PET, glucose metabolism PET, or tau PET – would finest predict future cognitive decline attributable to Alzheimer’s illness. Around 90 individuals had been recruited on the HUG Memory Centre.
“Our results show that while the various PET measures were all associated with the presence of cognitive symptoms, confirming their role as strong indicators of Alzheimer’s disease, tau PET was the best to predict the rate of cognitive decline, even in individuals with minimal symptoms,” summarises Cecilia Boccalini, a Ph.D. scholar in Professor Garibotto’s group and first creator of this research.
Detecting particular person variations
Amyloid plaques usually are not essentially accompanied by cognitive or reminiscence loss. However, the presence of tau goes hand in hand with scientific signs. Its absence or presence is the primary determinant of whether or not a affected person’s situation stays steady or deteriorates quickly. It has been tougher to develop imaging methods to visualise tau, primarily due to its decrease focus and notably complicated construction.
“This breakthrough is crucial for better management of Alzheimer’s disease. Recently, drugs targeting amyloid have shown positive results. New drugs targeting the tau protein also look promising. By detecting the pathology as early as possible, before the brain is further damaged, and thanks to new treatments, we hope to be able to make a greater impact on patients’ future and quality of life,” Valentina Garibotto factors out. “Similarly, we are beginning to map the distribution of tau in order to understand how its location in the different regions of the brain influences symptoms.”
Indeed, the causes and totally different levels of the illness are proving to be a lot much less uniform than beforehand thought, and particular person susceptibility to the identical phenomena must be higher understood.
These outcomes are a powerful argument in favor of incorporating tau PET into the routine scientific analysis to evaluate particular person prognosis and choose essentially the most acceptable therapeutic technique for every affected person.
Reference: “The impact of tau deposition and hypometabolism on cognitive impairment and longitudinal cognitive decline” by Cecilia Boccalini, Federica Ribaldi, Ines Hristovska, Annachiara Arnone, Débora Elisa Peretti, Linjing Mu, Max Scheffler, Daniela Perani, Giovanni B. Frisoni and Valentina Garibotto, 9 August 2023, Alzheimer’s & Dementia.
DOI: 10.1002/alz.13355
