population. If both parents have multiple
sclerosis, the child’s risk increases to 25%.Stem cells may stop slaughter
A brighter scenario may be developing for
sclerosis patients. A series of research
results indicate that stem-cell treatment
could be extremely effective and, in rare
cases, represent almost a cure against the
aggressive disease.
Put briefly, stem cells are undefined cells
that exist in all multicellular organisms —
undefined in that they can develop into
any and all types of cells. These cells have
been used successfully to treat other dis-
eases and injuries for many years,
including injuries to the nervous system in
the spinal column. And scientists are
working on three different stem-cell sclero-
sis treatments, two of which have already
been successfully tested on humans, while
the third has already produced promising
results in animals.In the first treatment tested, scientists
deliberately destroy the patients’ immune
systems by means of chemotherapy, then
subsequently persuade the stem cells to
build a new defence system from scratch.
The stem cells used are blood stem cells,
which can develop into immune cells. In this
way, the patients effectively get a entirely
fresh immune system, as they did when
they were babies. That can be both good andbad. On the one hand it means that the
immune system must get to know many
harmful organisms all over again – with the
patients meanwhile very vulnerable to a
number of diseases that could, at worst, be
fatal. But on the other hand, the immune
system is no longer confused between
friends and enemies. In this way scientists
are able to halt the ongoing slaughter of the
important myelin sheaths.Embryonic cells repair the brain
Stem-cell treatment is already sufficiently
recognised that it is offered to sclerosis pa-
tients in several Western countries, though
only to the most badly affected on whom
other drugs have no effect, given the risk of
severe infection from the treatment is high.
On the other hand, research shows that it
can remove the disease’s symptoms for at
least three years in 85% of patients. After six
years the percentage is approximately 65%,
and after eight years still around 60% of
patients have no symptoms – and for those
in which the disease does return it often
manifests in a milder version.
Another type of stem-cell treatment be-
ing developed, but not yet offered in hospi-
tals, has the potential not only to curb the
immune cells but also to repair some of the
damage the immune system has already in-
flicted on the nervous system. This is made
possible by means of mesenchymal stem
cells, which exist in the bone marrow and
can develop into bone, fat, and cartilage
cells. Scientists extract the stem cells from
the patients’ own pelvis bone marrow with
a needle and subsequently inject them into
the blood stream, where they travel to the
nerve cells. There they emit growth factors
which make the nerve cells repair them-
selves. So the patients avoid having their
immune systems destroyed, and face a
much lower risk of severe infection.
One more stem-cell treatment, which is
currently being tested on humans, makes
use of stem cells from the early stages of
fertilised eggs – embryonic stem cells. These
cells have the potential to develop into any
cell type, and scientists use this ability in the
lab, where the stem cells are converted into
early stages of the high-fat cells that help
nerve cells to communicate – the oligoden-
drocytes themselves.
If scientists manage to replace the
damaged nerve cells with cells made in the
lab, it could not only provide a treatment for
some of the world’s 2.3 million sclerosis pa-
tients, it might further pave the way for the
use of stem cells in the treatment of other
disorders that originate in the brain, such as
spastic paralysis in children.The myelin sheaths are
located around a nerve cell’s
fibre threads (blue) and
help cells to communicate.STE
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25%
is the risk that a child of
two parents with MS will
also develop the condition.60 | SCIENCE ILLUSTRATEDMEDICINE SCLEROSIS