- Scientists have harnessed the body's own natural defences
against infection to make a treatment for dementia.
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- A German team, from Friedrich-Wilhelms University, used
proteins or antibodies produced by people against disease.
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- Five Alzheimer's disease patients treated with the experimental
vaccine therapy showed improvement in tests.
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- More work is needed but the results are promising, said
the authors in the Journal of Neurology, Neurosurgery and Psychiatry.
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- Natural defence
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- People with Alzheimer's disease have 'amyloid' deposits
in the brain that are made up of a protein beta peptide.
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- These deposits get progressively worse and damage the
brain tissue, leading to dementia.
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- Scientists have been looking at ways of blocking the
action of beta peptide to prevent the build up of amyloid deposits using
vaccines.
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- Now Dr Richard Dodel and colleagues believe they have
found a way to do this, using the body's own natural defence system, in
humans.
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- When the body encounters a disease or infection it produces
complex protein molecules called antibodies to seek out and destroy the
invasion.
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- The researchers isolated antibodies against beta peptide
and injected these into patients with early Alzheimer's disease on a monthly
basis for six months.
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- To monitor the effect of this experimental treatment,
the scientists measured the levels of beta peptide in the cerebrospinal
fluid, which bathes the brain, at the beginning and end of the study.
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- They also tested the patients' brain function for things
like memory, which is affected by dementia.
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- At the end of the six months, levels of beta peptide
in cerebrospinal fluid fell by 30%, and the level of beta peptide in the
blood shot up 233%, suggesting that the treatment was working.
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- Although brain, or cognitive function improved only slightly
in four patients, it did not worsen, which would have been expected after
six months.
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- Promising start
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- Also, mental tasks improved in three patients and stayed
the same in the other two.
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- The scientists said although definitive conclusions could
not be drawn on the strength of a study of five patients, their findings
warranted further detailed investigation, and added weight to the experimental
evidence.
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- In an accompanying editorial, Alzheimer's experts Professor
Philip Scheltens and Dr Erik Hack from The Netherlands said: "Larger
studies are needed to confirm that this treatment can stabilise or even
improve cognitive functions in Alzheimer's disease."
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- But they said the study highlighted "a novel and
interesting" treatment option for Alzheimer's disease which seemed
"worthy to be explored".
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- Future research
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- Professor Clive Ballard from the Alzheimer's Society
said: "Whilst this is very encouraging, the safety and effectiveness
of this specific type of vaccine treatment needs to be carefully examined
in a larger trial."
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- He said there had been a lot of excitement about treating
Alzheimer's disease in this way.
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- "This approach proved to be very effective in animal
studies, leading to a clinical trial involving about 200 people with Alzheimer's
disease.
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- "Unfortunately, although the vaccine appears to
clear some of the protein from the brain, a substantial minority of participants
in the trial developed a serious complication called encephalitis (inflammation
of the brain), with two people dying.
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- "Therefore a lot of effort has been directed at
trying to further develop this vaccine treatment approach to enable it
to be used safely," he said.
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- In the current study, none of the five patients had major
side effects.
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- © BBC MMIV http://news.bbc.co.uk/2/hi/health/3658582.stm
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