New simple blood test developed for the early detection of Alzheimer's

Great success in Alzheimer's diagnostics

Against the widespread Alzheimer's dementia, there is currently no really convincing therapy option. According to experts, this is primarily because the disease can only be diagnosed at a late stage using current methods. At this stage, damage to the brain is already well advanced and irreversible. This will now be changed by a novel blood test, which should be suitable even for the routine use of broad masses.

The new blood test, according to the medical experts Alzheimer identify on average eight years before the current diagnostic options. A team of scientists from the Ruhr-Universität Bochum (RUB), the German Cancer Research Center (DKFZ) and the Saarland Cancer Registry showed this in a large cohort study. The underlying study for this blood test was published in 2017. Now the doctors with news on the subject.

In the brain of Alzheimer's patients, there are pathological deposits of the protein amyloid-beta, which can be visualized using imaging techniques such as amyloid-PET (right). (Source: K. Gerwert, A. Nabers / RUB)

Recognize Alzheimer's eight years earlier

"Our simple and cost-effective blood test can detect the disease even at a stage that is still asymptomatic", reports Professor Dr. med. Klaus Gerwert of the RUB and coordinator of the research consortium "PURE" in a press release. In addition, the blood test could identify people who have a particularly high risk of developing Alzheimer's.

Blood test opens new therapeutic approaches

"It is possible that drugs currently being tested in clinical trials may delay the progression of the disease if they are used at this early stage," explains Professor Dr. Hermann Brenner from the DKFZ, Department Head of Clinical Epidemiology and Aging Research. The development of novel therapeutic approaches could benefit enormously from this blood test for early detection.

Dementia is an increasing problem

"Dementia is on the rise and presents enormous challenges to those affected, relatives and society," says Monika Bachmann, the Saarland Minister of Social Affairs, Health, Women and Family. The Minister herself is an active participant in the cohort study.

How does the new test work?

In the onset of Alzheimer's disease misfolding of the protein amyloid-β are involved, which are deposited as clumps in the brain (amyloid plaque). This process begins 15 to 20 years before the first symptoms appear. The team led by Klaus Gerwert managed to develop a blood test that can detect this plaque in the blood. In the evaluation of the test, the ratio of healthy to diseased forms of amyloid β-proteins can be determined.

Previous diagnostic options are expensive and expensive

To date, Alzheimer's disease has been diagnosed at an early stage only with expensive imaging techniques, such as positron emission tomography (PET) or modified biomarkers in the cerebrospinal fluid. However, as these procedures remain costly and expensive, they are not suitable for screening broad populations.

The blood test does not have to shy away from the comparison

In comparisons with the complex diagnostic procedures, the new, relatively uncomplicated blood test performed well. In 70 percent of the cases, the new test identified the individuals who later actually had Alzheimer's. However, there was also an error rate of nine percent. These results describe the physicians as "false-positive".

Exclusive use at the moment still not possible

"At the moment, the test is not yet suitable for the sole early diagnosis of Alzheimer's because of the false positive results," says Gerwert. But it opens the possibility to filter out people in a cost-effective and minimally invasive screening, which should then undergo a further expensive and invasive diagnosis, which can exclude a false positive result.

Infrared sensor allows the test

The blood test is based on a so-called immuno-infrared sensor technology. The differently folded amyloid β-proteins absorb infrared light with different frequencies. Thus, the sensor can determine the ratio of healthy to pathological amyloid β in the sample.

In the future, the test should be suitable for routine use

Gerwert and his team are currently working hard on improving the sensor to filter out more patients and minimize the rate of false positives. The research team wants to improve the procedure to such an extent that the blood test device is no larger than a box of chocolates and provides such good results that it is suitable for routine use. (Vb)