Tuesday, 13 Apr 2021

Research into Alzheimer’s disease: a new blood test to detect early the disease

The blood test shows the course of Alzheimer’s disease long before the first clinical signs of

The number of people developing Alzheimer’s disease, is increasing worldwide. The neurodegenerative disease is still incurable. According to experts, this could be also due to the fact that the previous therapies start too late. In the future, could change that. Because with a new blood test for Alzheimer’s-tracks long before the disease discover the beginning.

Incurable Disease

In Germany alone, approximately 1.2 million people have dementia, the majority of affected by Alzheimer’s disease. Worldwide, there are approximately 47 million people with dementia. And more and more: According to the world Alzheimer’s report is provided every 3.2 seconds, a more dementia-diagnosis. The disease is not yet curable. This could be related, according to the experts, because the current therapies only late, partly because the disease is often diagnosed late. A team of researchers reported that Alzheimer’s disease-traces of which are found long before the onset of the Disease in the blood.

Early diagnosis is important

As with many other diseases, it is in the case of Alzheimer’s is important to diagnose the disease as early as possible.

Although the disease can not be cured currently, however, there is evidence that early diagnosis can delay disease progression.

Helpful for therapy research, a new blood could be a test.

Nerve cells are slowly degraded

Already years before the first symptoms of Alzheimer’s disease, the brain and nerve cells are slowly degraded.

Scientists at the German center for Neurodegenerative diseases (DZNE) and the Hertie-Institute for clinical brain research (HIH) and the University hospital of Tübingen have now shown that, on the basis of a in the blood occurring protein substance in the course of the disease long before the onset of the first clinical signs of track.

As it is stated in a joint press release, this blood test new possibilities in the therapy research.

The study was carried out jointly with an international research team and published in the journal “Nature Medicine” published.

Existing therapies are too late

“The fact that there is still no effective therapy against Alzheimer’s disease, probably because the current therapies much too late,” said Mathias Jucker, a researcher at tübingen, DZNE-site at the HIH and the head of the current study.

In order to develop better treatment procedures, need scientists, therefore, a reliable method with which you track the progression of the disease and to predict, before symptoms such as memory use disorders.

A blood test is much better than, for example, expensive brain scanner, make dementia early visible.

In the development of such blood tests have been achieved in recent times some progress. So Japanese and Australian researchers reported last year about a new Test for the early detection of the disease.

And also, German scientists have developed a blood test for the early detection of Alzheimer’s disease.

In the words of the current message, based most of these methods on the detection of so-called Amyloid proteins. In the case of Alzheimer’s disease, these proteins accumulate in the brain and also occur in the blood.

Jucker and colleagues pursue a different approach. “Our blood test does not measure the Amyloid, but what causes it in the brain, namely Neurodegeneration. In other words: the death of nerve cells,“ said Jucker.

Traces in the blood

When brain cells die, their Remains in the blood to demonstrate. “Normally, such proteins are reduced in the blood but quickly, and are therefore not very well as a Marker for a neurodegenerative disease,” said Jucker.

“An exception is a small piece of a so-called neuro-filament, which is against the removal amazingly resistant forms”.

This protein substance of the blood test, Jucker and his colleagues is based.

The scientists show in the current study, the Filament accumulates long before the appearance of clinical symptoms – so, already in the preclinical Phase in the blood, that it reflects very sensitive to the course of the disease and predictions about future developments.

According to the figures available the study is based on data and samples of 405 persons, which were collected in the framework of an international research network – the “Dominantly Inherited Alzheimer Network” (DIAN)–.

In addition to the DZNE, the HIH and University clinic Tübingen, the Washington University School of Medicine in St. Louis (United States), as well as other institutions all over the world.

This network studied families in which due to genetic changes, Alzheimer’s disease occurs in middle age. Genetic analyses allow for some pretty accurate predictions about whether and when a family member is developing dementia.

Harbingers of dementia

In these individuals, the scientists followed the development of the Filament concentration from year to year, and turned out to be: Up to 16 years before the expected Occurrence of dementia symptoms, there was in the blood, eye-catching changes.

“It is not the absolute value of the Filament concentration, but their temporal development, which is really meaningful and to predict the further course of the disease,” said Jucker.

In further studies, the researchers showed that the change in the Neurofilament concentration reflects the neuronal removal very accurate and good predictions it allows, how the brain will develop in the next few years.

“We were able to make predictions about the loss of brain mass and cognitive impairments, which are then joined, two years later, in fact,” says Jucker.

So while it turned out that the rate of change of the Filament concentration and the removal of brain tissue correlated closely with each other, had pronounced the connection with the deposition of toxic Amyloid proteins.

This observation supports the hypothesis that Amyloid proteins are a trigger for the disease, the neuronal reduction takes place in the further course independently.

Tool for therapeutic research

Not only in Alzheimer’s, other neurodegenerative diseases, it comes in the blood to the accumulation of neuro-filaments.

Thus, the Test is suitable only to a limited extent for the diagnosis of Alzheimer’s disease.

“The Test shows very exactly the course of the disease and is thus an excellent tool to explore in clinical trials of new Alzheimer’s therapies,” said Jucker. (ad)