Your doctor might want to validate which of these percentages is accurate for their patients
Has your doctor/hospital done anything since these earlier research results?
1. Your 33% dementia chance post-stroke from an Australian study? May 2012.
2. Then this study came out and seems to have a range from 17-66%. December 2013.
3. A 20% chance in this research. July 2013.
Novel blood test for Alzheimer’s diagnosis
Ruhr-Universitaet-Bochum
Today, Alzheimer’s disease is diagnosed too late. In
collaboration with a research team at the university and German Center
for Neurogenerative Diseases (DZNE) in Göttingen, Researchers at
Ruhr-Universität Bochum (RUB) have developed a blood test that may
potentially facilitate detection of Alzheimer’s at an early stage. It is
based on an immuno-chemical analysis using an infrared sensor.
The sensor’s surface is coated with highly specific antibodies which
extract biomarkers for Alzheimer’s from the blood or the cerebrospinal
fluid, taken from the lower part of the back (lumbar liquor). The
infrared sensor analyses if the biomarkers show already pathological
changes, which can take place more than 15 years before any clinical
symptoms appear. This method has been featured as the cover story in the
internationally renowned academic journal “Biophotonics”, and the
results of the study were also published in “Analytical Chemistry”.
In most instances, diagnosis is too late
A major problem of Alzheimer’s disease diagnosis is the fact that, by
the time the first clinical symptoms appear, massive irreversible
damage to the brain has already occurred. At that point, symptomatic
treatment is the only available option. “If we wish to have a drug at
our disposal that can significantly inhibit the progress of the disease,
we need blood tests that detect Alzheimer’s in its pre-dementia
stages,” says Prof Dr Klaus Gerwert, Head of the Department of
Biophysics at RUB. “By applying such drugs at an early stage, we could
prevent dementia, or at the very least delay its onset,” adds Prof Dr
med. Jens Wiltfang, Head of the Department for Psychiatry and
Psychotherapy at the University of Göttingen and Clinical Research
Coordinator at DZNE Göttingen.
Morbus Alzheimer’s and misfolding of Amyloid beta peptide
For the novel test, the secondary structure of the so-called Amyloid
beta peptides serves as biomarker. This structure changes in
Alzheimer’s patients. In the misfolded, pathological structure, more and
more Amyloid beta peptides can accumulate, gradually forming visible
plaque deposits in the brain that are typical for Alzheimer’s disease.
This happens more than15 years before first clinical symptoms appear.
The pathological beta Amyloid plaques can be temporarily detected by
positron emission tomography, short: Amyloid PET; but this procedure is
comparatively expensive and is accompanied by radiation exposure.
Patented diagnostic method for Alzheimer’s detection
Together with Prof Dr med. Jens Wiltfang from Göttingen, the team
headed by Prof Dr Klaus Gerwert has developed an infrared sensor for
detecting misfolding of Amyloid beta peptides as part of the PhD
research projects of Andreas Nabers and Jonas Schartner. The infrared
sensor extracts the Amyloid beta peptide from body fluids. The method is
patent pending. After initially working with cerebrospinal fluid, the
researchers subsequently expanded the method towards blood analysis. “We
do not merely select one single possible folding arrangement of the
peptide; rather, we detect how all existing Amyloid beta
secondarystructures are distributed, in their healthy and in their
pathological forms,” says Gerwert. Precise diagnostics is not possible
until the distribution of all secondary structures is evaluated. Tests
that analyse Amyloid beta peptide are already available with so-called
enzyme-linked immunosorbent assays (ELISA). They identify the total
concentration, percentage of forms of different length, as well as the
concentration of individual conformations in body fluids; but they have
not, as yet, provided information on the diagnostically relevant
distribution of the secondary structures at once. “This is why ELISA
tests have not been proven very effective when applied in blood sample
analysis in practice,” explains Klaus Gerwert.
First clinical trials completed
Using the methods now developed in Bochum and Göttingen, the
researchers have analysed samples from 141 patients. They have achieved a
diagnostic precision of 84 per cent in the blood and 90 per cent in
cerebrospinal fluid, compared with the clinical gold standard. The test
revealed an increase of misfolded biomarkers as spectral shift of
Amyloid beta band below threshold, thus diagnosing Alzheimer’s. “What’s
unique about it is that this is the only robust label-free test with a
single threshold,” as Andreas Nabers describes the result of his
dissertation.
A potential sensor for early detection
As part of the published study, the researchers have tested the
potential for early detection of Morbus Alzheimer’s on a small group of
patients. The results suggest that even in pre-dementia stages, an
increased concentration of misfolded Amyloid beta peptides can be
detected in body fluids. Thus, Morbus Alzheimer’s may in future be
diagnosable in preclinical stages. “The sooner Alzheimer’s is detected,
the better the therapy chances. This sensor is an important milestone in
the right direction,” adds Prof Dr Jens Wiltfang. Currently, sample
analyses for early detection in 800 study participants are being
conducted, in order to optimise statistical significance.
http://aktuell.ruhr-uni-bochum.de/pm2016/pm00034.html.en
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