Early blood test for Alzheimer's

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

More posts by Christiane Fux All content is checked by medical journalists.

These pathological amyloid beta proteins clump together and deposit as amyloid plaques in the brain. For a long time the disease could only be diagnosed with certainty after death by means of an autopsy based on these plaques.

For some time now, this has also been possible with a brain scan or an examination of the spinal cord fluid for pathological amyloid beta. But these examinations are time-consuming, stressful and expensive for the patient. They are therefore not suitable for screening for the early detection of Alzheimer's disease.

A team led by Prof. Klaus Gerwert from the Ruhr University Bochum, together with colleagues from the German Cancer Research Center (DKFZ) and the Saarland Cancer Register, developed a blood test that can detect Alzheimer's disease eight years before the onset of the disease.

Detect Alzheimer's disease with infrared light

To do this, the researchers examined blood samples that had been collected as part of the ESTHER * study in 2000 using a special infrared Senso technology.

Diseased and healthy beta-amyloid absorb infrared light with different frequencies. In this way, the researchers were able to determine the ratio of normal and misfolded proteins in the blood of the participants.

Hit rate 70 percent

In the 65 participants who later actually developed Alzheimer's disease, the test recognized the impending disease an average of eight years earlier. With the remaining 30 percent, it did not work.

However, there were also false alarms of their own: Of the 809 study participants who remained healthy, the test also announced the diagnosis of Alzheimer's in nine percent and thus delivered a “false-positive” result.

Filters for suspected cases

At the moment, the test is therefore not yet suitable for the sole early diagnosis of Alzheimer's, explains Gerwert. But in this way, suspected cases can be filtered out inexpensively and gently for the patient, which can then be clarified with a more precise procedure.

Late diagnosis complicates the search for active substances

So far it has not been possible to find drugs that can be used to cure the disease. One possible reason is that Alzheimer's is only recognized at a late stage, when characteristic symptoms such as forgetfulness have already appeared. The underlying brain damage may then be too advanced to be treated successfully.

Can Alzheimer's be slowed down in its early stages?

At an early stage, however, it could look different: "It is possible that drugs that are currently being tested in clinical studies can stop the progression of the disease if they are used at this early stage," says Prof. Hermann Brenner from the DKFZ, who also participated in the study.

Why early detection makes sense even without a cure

Even without a current healing perspective, there are some arguments in favor of early detection of Alzheimer's. It is true that the certainty of being terminally ill can be very stressful. The knowledge also enables those affected to make the best possible use of the remaining symptom-free time.

You may also be able to delay the onset of the disease by making lifestyle changes that include plenty of exercise, a healthy diet, and mental stimulation. There is still no clear evidence that this is possible, but there is strong evidence.

In addition, those affected can make decisions and arrangements for when they will no longer be able to do so.

* ESTHER: Epidemiological study on the chances of prevention, early detection and optimized therapy of chronic diseases in the elderly population

Klaus Gerwert, Hermann Brenner et al .: Amyloid blood Biomarker detects Alzheimer's disease. EMBO Molecular Medicine, 2018, DOI: 10.15252 / emmm.201708763

Tags:  smoking Menstruation hospital