A blood test can diagnose Alzheimer's disease

Dementia research Detect Alzheimer's risk early on with a blood test

As the Ruhr University Bochum and the German Cancer Research Center (DKFZ) explained in a joint press release, researchers have developed a blood test that can determine the risk of Alzheimer's disease on average eight years before a clinical diagnosis.

Guilt is a protein

To date, there is no effective therapy against this brain disease. Experts suspect that the main reason is that Alzheimer's can only be diagnosed at a late stage, when the brain damage is already very advanced. A typical symptom is the patient's forgetfulness.

In Alzheimer's disease, amyloid beta protein is misfolded about 15 to 20 years before the onset of the disease. The protein clumps and deposits amyloid plaque in the brain.

Early detection of plaque deposits

The newly developed blood test can determine whether the patient's brain is already contaminated with the amyloid plaque. The ratio of healthy and defective amyloid proteins is determined. And on average eight years before Alzheimer's disease broke out. So far it has only been possible to diagnose Alzheimer's at such an early stage by using imaging techniques. On the one hand, these are invasive because, for example, spinal fluid is examined. On the other hand, they are very expensive. The new test uses the fact that the healthy and the diseased structure of the protein absorb infrared light with a different frequency and are thus distinguishable.

Well suited for screening

However, the blood test is not yet suitable for the sole early diagnosis of Alzheimer's disease. In 70 percent of the cases, he identified the people who later actually developed Alzheimer's dementia. Nine percent of the test subjects remained healthy, although the Alzheimer's test was positive.

"Nevertheless, the test opens up the possibility of filtering out people in a cost-effective and minimally invasive screening who should then undergo a further, expensive and invasive diagnosis that can rule out a false-positive result," says protein researcher Prof. Dr. Klaus Gerwert von the Ruhr University Bochum.

A topic for a long time

A method for the early diagnosis of Alzheimer's has been researched for a long time. A Japanese-Australian research team announced in February that they had developed a blood test based on the amyloid beta protein. And as early as 2014, the American team of scientists led by Dr. Mark Mappstone of the University of Rochester developed a blood test. He was able to diagnose Alzheimer's three years before the disease broke out using certain blood lipids.

Treat Alzheimer's?

The German researchers hope that early detection will soon lead to therapy. "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," explains Prof. Hermann Brenner, epidemiologist and geriatric researcher at the DKFZ Experts benefit enormously from this early blood test.