Millions of people worldwide suffer from dementia. There is currently no cure for the disease. However, treatment can alleviate the associated symptoms and improve the quality of life of those affected. Early diagnosis is crucial. However, this is usually only asked after the first symptoms appear. That could possibly change in the future. Researchers have now succeeded in identifying proteins in the blood that can predict dementia up to 15 years before clinical diagnosis.

For their study, which was published in the specialist magazine “Nature Aging”, scientists from the University of Warwick and Fudan University in Shanghai examined the blood of more than 50,000 healthy adults. The samples were collected in 2006 and 2010. In the following years, a total of 1,417 of the participants developed dementia.

The result: Using samples taken years earlier, the researchers identified conspicuous protein biomarkers – which were already evident in the blood back then. Higher levels of the four proteins GFAP, NEFL, GDF15 and LTBP2 were warning signs of later dementia.

Inflammation in the brain can cause cells called astrocytes to overproduce GFAP. According to the study, people with elevated GFAP levels were more than twice as likely to develop dementia as people with lower levels. The blood protein NEFL is linked to nerve fiber damage, while elevated GDF15 levels can occur after brain blood vessel injury.

Combined with more conventional risk factors such as age, gender, education and genetic susceptibility, the protein profiles allowed the study authors to predict Alzheimer’s and vascular dementia with 90 percent accuracy, almost 15 years before the disease was clinically confirmed. “Studies like this are needed if we want to intervene with disease-modifying therapies in the earliest stages of dementia,” says Amanda Heslegrave from University College London. The neuroscientist was not involved in the study

According to the World Health Organization (WHO), more than 55 million people worldwide are currently living with dementia – a number that is expected to rise to 78 million by 2030. The diagnosis is often only made when those affected notice memory problems or other symptoms. At this point, the disease may have been progressing for years. “Once we diagnose it, it’s almost too late,” says study co-author Jian-Feng Feng, a computational biologist at Fudan University. “And it’s impossible to undo it.”

He and his colleagues hope the blood test can revolutionize the diagnosis of dementia and lead to earlier and preventative treatment. In the future, drugs could be developed that interact with the identified proteins. They also want to further develop the tests in collaboration with companies. The cost of the blood test currently amounts to several hundred dollars and still needs to be examined by the authorities.

It is estimated that 1.8 million people live with dementia in Germany. Most of them suffer from Alzheimer’s disease, the most common form of dementia. The disease begins gradually, usually with memory and orientation problems. The Federal Ministry of Health names the following warning signs of dementia:

The symptoms mentioned can also have other causes, such as stress, psychological stress, a change in the hormonal balance or another illness. Forgetfulness can also vary in severity among people. Nevertheless: If you suspect dementia, you should urgently consult your family doctor.

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