Tau-PET imaging enables earlier, more accurate Alzheimer’s diagnosis

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A brain imaging technology called tau-PET can improve Alzheimer’s diagnostics in health care, according to a study from the University of Gothenburg. The technology enables earlier diagnosis and robustly identifies people at highest risk—even before symptoms appear.

Tau-PET is a relatively new technique that shows the accumulation of tau protein, a biological marker of Alzheimer’s disease. It is thus far mainly used in research but is now approved for clinical use and has great potential in health care and clinical trials.

Approved for clinical use

The study is the largest of its kind in the world, analyzing data from over 6,500 people in 13 countries as part of an international collaboration. The researchers used the method now approved by European and US drug authorities for image interpretation in clinical practice.

The study results, published in JAMA, demonstrate that around 10% of healthy older people around the age of 75 already had high levels of tau protein in their brains, even though they did not yet show any symptoms. The proportion increased with age and with the degree of memory impairment.

Among these individuals—with both tau and amyloid protein in the brain—the risk of developing mild cognitive impairment or dementia was 57% within five years. For those who already had mild memory problems, the risk rose to 70%.

The principal investigator behind the study is Michael Schöll, professor of molecular medicine at the Sahlgrenska Academy at the University of Gothenburg:

“When both tau and amyloid are present in the brain, we see a clearly increased risk of developing Alzheimer’s disease within a relatively short period of time. This makes tau-PET a clinically highly relevant method, as it reflects the progression of the disease, provides valuable information for early treatment decisions, and enables better participant selection for treatment studies. Our results may have a major impact on how the method is used in both clinical practice and future treatment studies,” he says.

Guidance for treatment

Blood tests that associate with amyloid accumulation in the brain are soon becoming an important, easily accessible diagnostic tool in health care for suspected Alzheimer’s disease.

However, according to the researchers, tau PET, which is a more specialized method, provides crucial complementary information and a more accurate picture of both how far the disease has progressed and what may happen in the future.

Alexis Moscoso Rial is an affiliated researcher at the Sahlgrenska Academy at the University of Gothenburg and the study’s lead author. “Tau PET is the most robust biomarker that can reliably show who has Alzheimer ‘s-related brain changes and is truly at risk of developing memory loss and dementia,” he says.

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