MUHC study identifies procedure that detects early stages.
MUHC study identifies procedure that detects early
stages.
A new blood test that will diagnose Alzheimer's disease may soon
hit the market, thanks to an innovative study from the Research
Institute of the McGill University Health Centre (MUHC). Their
findings have characterized a unique biochemical diagnosis, which
identifies patients with this devastating disorder. This research,
published in the month's issue of the Journal of Alzheimer's
Disease, has implications for the half-a-million Canadian
sufferers and many millions more worldwide.
"Until now, there has been no definitive diagnostic tool for
Alzheimer's, other than postmortem analysis of brain tissue," says
senior author Dr. Vassilios Papadopoulos, director of the MUHC
Research Institute. "Our clinical study shows that a non-invasive
blood test, based on a biochemical process, may be successfully
used to diagnose Alzheimer's at an early stage and differentiate it
from other types of dementia."
The biochemistry behind the test
Papadopoulos and colleagues based the Alzheimer's blood test on
the production of a brain hormone called dehydroepiandrosterone
(DHEA). This hormone is present at high levels in the brain where
it has a wide range of biological effects.
The researchers were able to promote the production of DHEA,
using a chemical process called oxidation, in blood taken from
non-Alzheimer's patients. However, oxidation of blood from
Alzheimer's patients did not result in an increase of DHEA.
"There is a clear correlation between the lack of ability to
produce DHEA through oxidation in the blood and the degree of
cognitive impairment found in Alzheimer's disease," says
Papadopoulos. "We demonstrated we could accurately and repetitively
detect Alzheimer's disease, with small samples of blood. This
test also allowed for differential diagnosis of early stages of
Alzheimer's disease, suggesting this can be used as a test to
diagnose the disease in its infancy."
Treatment implications
"There are many candidate disease-modifying therapies that
target the underlying development of Alzheimer's disease, which are
in clinical trials," adds Papadopoulos. "However, the
implementation of any therapy is dependant on the reliability of
the diagnosis."
Currently the diagnosis of Alzheimer's follows the sequence of
family history, information, mental assessment and the physical
exam, focusing on neurological signs.
"An accurate, easy and specific non-invasive biochemical test
that correlates with clinical findings is vital. We believe our
results demonstrate that the DHEA-oxidation blood test can be used
to diagnose Alzheimer's at a very early stage and monitor the
effect of therapies and the evolution of the disease."
About this study:
The study, A lead study on oxidative stress-mediated
dehydroepiandrosterone formation in serum: The biochemical basis
for a diagnosis of Alzheimer's disease, was authored by
Georges Rammouz, Laurent Lecanu and Vassilios Papadopoulos from the
MUHC Research Institute and McGill University; Paul Aisen from the
University of California at San Diego.
Partners in research:
This work was supported by funds from the National Institutes of
Health and Samaritan Pharmaceuticals.
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