Potential for early test for Alzheimer's
Research in mice could lead to an early test for Alzheimer’s disease,
say scientists.
A key event in the development of Alzheimer’s disease is the conversion
of amyloid-beta peptides from soluble to insoluble forms in the brain.
This is estimated to occur between 10 and 20 years before cognitive symptoms
appear. However, previous attempts to measure levels of amyloid-beta peptides
have been unsuccessful because baseline plasma levels do not correlate
with brain amyloid-beta peptide burden.
Now Dr Ronald DeMattos, centre for the study of nervous system injury,
Washington University school of medicine, and colleagues have discovered
a way to measure plasma amyloid peptides in mice. They gave mice m266,
a monoclonal antibody that causes a massive increase in the amount of
central nervous system-derived amyloid-beta peptide deposited in the plasma.
Before administration, as expected, baseline plasma levels of amyloid-beta
peptide did not correlate with the amount of peptide present in the brain.
However, after administration of m266, a highly significant correlation
between plasma and brain levels of amyloid-beta peptides was found.
Whether or not m266 will yield similar results in humans is not known.
The researchers conclude: "The use of a monoclonal antibody with
characteristics similar to m266 but developed for humans may provide a
means to develop a facile diagnostic test to quantify amyloid burden in
persons with pre-clinical Alzheimer’s disease, as well as to assist
in the differential diagnosis of clinical Alzheimer’s disease. Such
a test may also have utility for monitoring the response to anti-amyloid
therapy." The study is published in Science (2002;295:2264).
Commenting on the study’s findings, Dr Richard Harvey, director of
research, Alzheimer’s Society, said: "Developing ways of detecting
and identifying dementia earlier, and even before significant symptoms
appear, is becoming increasingly important as we see new treatment and
prevention strategies emerging."
However, he added: "Developing a simple, reliable diagnostic test
has been and remains one of the holy grails of dementia research. If this
new research can be successfully translated into human trials, and really
can identify people early in the illness, then it will undoubtedly be
very useful."
Back to Top
|
