Today's Alzheimer's detecting techniques only work once typical plaques have formed in the brain, a point where therapy is no longer an option. However, studies show that the first changes caused by the disease take place on the protein level up to 20 years earlier.
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Detection at a much earlier stage
Now, researchers at Ruhr-Universität Bochum (RUB) have developed a two-tier method that can help detect the disease at a much earlier stage improving the chances of treatment.
"This has paved the way for early-stage therapy approaches, where the as yet inefficient drugs on which we had pinned our hopes may prove effective," says Professor Klaus Gerwert from the Department of Biophysics at RUB.
The technique focuses on successfully diagnosing the amyloid beta protein folds approximately eight years before the first clinical symptoms occur. The technique consists of a simple blood test.
However, at first trial the test detected 71 % of Alzheimer's cases in symptomless stages, but also resulted in 9% false positive. As such, the researchers further optimized their test.
To do this they introduced a second biomarker. The researcher now use the first blood test to identify high-risk individuals and further add a dementia-specific biomarker to run a second set of tests.
"Through the combination of both analyses, 87 of 100 Alzheimer's patients were correctly identified in our study," summarises Klaus Gerwert. "And we reduced the number of false positive diagnoses in healthy subjects to 3 of 100. The second analysis is carried out in cerebrospinal fluid that is extracted from the spinal cord.
"Now, new clinical studies with test participants in very early stages of the disease can be launched," points out Gerwert. He is hoping that the existing therapeutic antibodies will still have an effect. "Recently, two major promising studies have failed, especially Crenezumab and Aducanumab - not least because it had probably already been too late by the time therapy was taken up. The new test opens up a new therapy window."
Before amyloid plaques form
"Once amyloid plaques have formed, it seems that the disease can no longer be treated," says Dr. Andreas Nabers, head of the research group and co-developer of the Alzheimer's sensor. "If our attempts to arrest the progression of Alzheimer's fail, it will put a lot of strain on our society."
The blood test has been upgraded to a fully automated process at the RUB Department of Biophysics. "The sensor is easy to use, robust when it comes to fluctuation in concentration of biomarkers, and standardised," explains Andreas Nabers. "We are now conducting in-depth research to detect the second biomarker, namely tau protein, in the blood, in order to supply a solely blood-based test in future," concludes Klaus Gerwert
The study was published in the March 2019 edition of the journal Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring.