Immunoglobulins which are already being used to treat multiple sclerosis
may also be able to help patients with Alzheimer's. This, at least, is
the finding of a pilot study on five patients at the University of Bonn.
The results are set out in the forthcoming edition of the Journal of
Neurology, Neurosurgery and Psychiatry (vol. 75, pp. 1472-1474), which
also devotes its editorial to this discovery.
Immunoglobulins contain, among other things, anti-bodies against a
protein which is the 'main suspect' thought to trigger off Alzheimer's.
After six months of immuno-globulin doses the concentration of this
protein in the patients' cerebrospinal fluid was reduced by one third.
The patients' cognitive abilities improved slightly.
However, the medical team involved emphasise that their findings are
still very tentative. They are now planning a large-scale double-blind
clinical trial with about sixty patients so as to further confirm the
positive effect of the immunoglobulins.
The cerebral cortex of Alzheimer's patients regularly contains large
protein aggregates, what are known as Alzheimer's glands. They
predominantly consist of beta-amyloid peptide, a small protein. This
peptide collects in the brain of Alzheimer's patients and forms protein
deposits which can damage and even destroy the sensitive nerve cells.
A promising approach in combating the disease seems to be the treatment
with anti-bodies which are specifically effective against beta-amyloid.
Thus, in animal experiments the injection of beta-amyloid anti-bodies
led to a reduction in the protein deposits and an improvement in the
behavioural deficits in these animals. Another study recently showed
that immunising was not only able to reduce amyloid plaques, it also
prevented the formation of the abnormal tau protein.
Recently the team led by the Bonn lecturer Dr. Richard Dodel was able to
show that every person's blood contains anti-bodies against
beta-amyloid, but that the concentra-tion in Alzheimer's patients is
markedly lower. Their findings have been confirmed by two US teams.
'There are already anti-body blood preparations which are used for
particular diseases of the nervous system such as multiple sclerosis,
which are known as immunoglobulins,' Dr. Dodel explains. 'We have now
investigated whether these preparations contain anti-bodies against
beta-amyloid and if these can be used to fight Alzheimer's.' His team
did in fact find anti-bodies in one type of immunoglobulin medication
which are very effective specifically against beta-amyloid. In a pilot
study carried out on five Alzheimer's patients the team then studied the
effect of the immunoglobulins on the progress of the disease. This
involved giving the patients an immunoglobulin injection intravenously
every four weeks throughout the six-month study. Before beginning and on
completing the therapy the researchers determined the beta-amyloid
content in the blood and the CSF fluid – the latter being the liquid
which is present in the brain and spinal cord. 'On average the
beta-amyloid concentra-tion in the fluid decreased in the course of the
study by over 30 per cent, while the concentration in the blood rose 2.3
times,' Dr. Dodel says. 'The immunoglobulins therefore seem to have the
effect of flushing out the beta-amyloid from the brain' – how exactly
this occurs is as yet unclear.
At the same time the team carried out various tests which enabled them
to check the cerebral performance of dementia patients. After six months
four of the five patients did slightly better than before in what is
known as the ADAS-cog test (Alzheimer's Disease Assessment Scale,
cognitive subscale). In the MMSE (Mini-Mental State Examination) test
three patients improved. 'What is even more remarkable is that none of
our test persons deteriorated,' Dr. Dodel explains. 'Without treatment
Alzheimer's patients on average score seven to eleven points worse in
the ADAS-cog test one year later, and even patients on medication score
four to six points worse. In our study they improved on average by 3.7
points.'
However, the sample was far too small to be able to draw firm
conclusions about the effectiveness of immunoglobulin therapy, since the
substance was not tested in comparison with a placebo. 'We only carried
out a pilot study,' Dr. Dodel emphasises; 'in order to confirm our
findings we definitely need to carry out a double-blind trial with
larger patient numbers
[Homestead] Alzheimers, the horror-story that is everybody's worst enemy,
Tvoivozhd, 09/21/2004