Researchers
Make Progress In Finding Ways To Treat MS
March
Is National Multiple Sclerosis Education and Awareness Month
There are no clear
or easy answers when it comes to multiple sclerosis (MS).
MS, a central
nervous system disease, is one of the most common neurological
disorders among young adults.
According to the National
Multiple Sclerosis Society, about 400,000 Americans
and 2.5 million people worldwide suffer from the disease, more
often women than men.
Consider the following
statistics on MS, compiled by the National Center for
Health Statistics (NCHS) of the Centers for
Disease Control and Prevention (CDC):
-
In 1999 to 2000,
there were approximately 700,000 visits to a physician
each year that included a diagnosis of multiple sclerosis.
-
In 1999 to 2000,
24,000 annual hospitalizations listed multiple sclerosis
as the first diagnosis. Nearly 63,000 other hospitalizations
listed it as an additional diagnosis.
-
Females accounted
for 75 percent of all hospitalizations that mentioned
MS.
The diagnosis of MS
is most often made when the person is young, between the ages
of 20 and 30. This is exactly the time many men and women are
planning marriage, contemplating children, and establishing
careers.
No one knows what
causes MS, for which there is no cure, although promising treatments
are under review. But the likely cause appears to be a combination
of genetics and environmental factors, and involves an immune
system gone awry.
"We believe it is
an autoimmune disease where the immune system is targeting its
own body," says Patricia O'Looney, director of biomedical research
at the National Multiple Sclerosis Society
in New York City.
While symptoms of
MS can include numbness or weakness in the arms or legs, unsteady
gait and blurred vision, no two people experience the disease
the same way.
"One year the person
is fine with or without treatment and the next year they have
an exacerbation, with or without treatment," O'Looney says.
"It's very difficult."
The progression of
the disease is generally not a steady one, but involves exacerbations
- or flare-ups - punctuated by periods of stability. No one
knows what triggers an exacerbation.
But as the nation
marks National Multiple Sclerosis Education and Awareness
Month in March, the news is not all bad.
Patient
Experiences Vary from Year to Year
For instance, researchers
at the Mayo Clinic in Rochester, Minn., followed all residents
with MS in Olmsted County, Minn., from 1991 to 2001.
They found that only
about one-third have severe disease, with about 70 percent reporting
only a mild increase in disability over the 10-year time span.
"I think that's very,
very comforting to patients with MS," says Dr. Moses Rodriguez,
senior author of the research, which appeared in the medical
journal Neurology.
"A lot of patients
do very, very well, and the reason is that they have protective
responses," Dr. Rodriguez says. "If we could figure out more
about what makes those patients do well, we'd have an important
clue. This tells us this is a disease we can live with."
Until that is determined,
however, existing treatments serve mainly to limit the number,
duration, or severity of exacerbations, but they don't eliminate
attacks. Other treatments try to turn off the immune system
one way or another.
None of these treatments,
obviously, constitutes a cure. Research today is looking toward
a cure and toward more successful therapies.
"The direction of
clinical treatment today is to find a better treatment and most
likely it will be a combination treatment," O'Looney says.
"The available therapies
that we have give us a 30 to 35 percent reduction in our measures
of relapse rate and disability," adds Dr. Fred Lublin, director
of the Corinne Goldsmith Dickinson Center for Multiple Sclerosis
at Mount Sinai Medical Center in New York City.
"Ten years ago, we
didn't have any therapies," Dr. Lublin says. "We're delighted
to have those, but we now need to move forward and do better.
One way would be to combine therapies that have different putative
mechanisms of action."
Immune
System Studied
Dr. Lublin's center
recently received a $30 million National Institutes
of Health grant to look at the combined effect of the
drugs interferon beta 1a and glatiramer acetate on immune functioning.
Experts do know that
MS involves the destruction of myelin, or the protective sheath
of fatty tissue that surrounds nerve fibers and helps them conduct
electrical impulses.
More recently, researchers
have discovered that the axon or nerve cell is also damaged,
which makes sense. Because it has lost its protective covering,
the axon becomes vulnerable to attack from the body's own immune
cells.
"There is an immediate
need to not only control the immune system but to try to find
ways to repair myelin so as to protect the axons," O'Looney
says.
The big challenge
is figuring out how to replace myelin that is being destroyed.
Scientists are grappling with basic questions such as: Can you
stimulate cells that make myelin? Can you stimulate them to
make more using growth factors?
The other problem
is that the myelin damage is not just in one location, but several.
"These are troubling
questions for researchers to try to identify which cells to
use to repair myelin," O'Looney says. "Can it repair cells?
Does it restore function? How do you repair damage in all areas?"
Last year saw a number
of other research gains. An early phase clinical trial of the
monoclonal antibody AntegrenTM showed
promising results. Another study found that ZocorTM,
a cholesterol-lowering drug, reduced the number of new brain
lesions in a small group of people.
Other studies suggest
that smoking may somehow increase susceptibility to MS, and
that sun exposure from age six to 15 may actually be associated
with a lower risk for MS. This last point may have to do with
increased production of vitamin D, which occurs in the body
as a result of sun exposure.
Always consult your
physician for more information.
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March 2004
Researchers
Make Progress In Finding Ways To Treat MS Patient
Experiences Vary from Year to Year Immune
System Studied MS
Expert Talks About A Promising Approach Online
Resources
MS
Expert Talks About A Promising Approach When
Dr. Moses Rodriguez started researching multiple sclerosis two decades
ago, the prevailing wisdom was that repairing the nervous system was
impossible. Now
he knows that's not true.
Dr. Rodriguez, a professor of neurology and immunology at the Mayo Clinic
in Rochester, Minn., was intrigued by MS patients who had devastating
attacks and then, one year later, seemed to be dramatically better.
"We hadn't done anything,"
he says. "The body had been able to do something to induce repair."
In the intervening years,
Dr. Rodriguez has been able to identify a whole series of antibodies
that were able to perform dramatic repairs in animal tests of MS.
"We have been able to show
definitely that we can get very significant repair of the nervous system,"
he says. These
antibodies are part of the body's natural defense system.
"They are present in all of
us and are playing a role in repairing our bodies," Dr. Rodriguez explains.
In people with MS, however, they are present at only low levels.
"It's very exciting, because
theoretically it should be very nontoxic," Dr. Rodriguez says. "You're
giving back. It's a normal, very natural, reparative kind of approach.
Most approaches in MS have been destructive. People are trying to get
rid of T cells or immunosuppress people or take away things."
Now Dr. Rodriguez and his
colleagues have identified antibodies in humans and have unraveled the
complete molecular sequence, meaning they can manufacture them.
In fact, Dr. Rodriguez is
planning clinical trials in collaboration with Acorda Therapeutics.
"The company is committed
to taking this forward; I think it's going to happen relatively soon,"
Dr. Rodriguez says. Dr.
Rodriguez has departed from conventional MS research in another way
as well. Traditionally,
experts have focused on the myelin sheath, which insulates the axon
or nerve cell. "What
we're finding is the real problem is in the neuron or axon, not the
myelin," Dr. Rodriguez says. "We may be concentrating on the wrong thing.
Once we get over that big step, we may be able to find more effective
therapies." Without
myelin, the axon is like "a tree without bark," Dr. Rodriguez explains.
"All of a sudden, anything can get into it and the axon is going to
die. One of the things you've got to do is protect those axons from
dying." Killer
T-cells, which are part of the body's immune system and the most common
T cells in the brains of MS patients, appear to be killing the axons.
When Dr. Rodriguez and his
colleagues deleted killer T-cells in animal models, the animals showed
no neurological problems. "That
shows that killer T cells are the bad guys," he says. "If we can get
rid of killer T-cells, we can do a lot." Always
consult your physician for more information.
Online
Resources (Our
Organization is not responsible for the content of Internet sites.)
Centers
for Disease Control and Prevention (CDC) Multiple
Sclerosis Association of America National
Institute of Neurological Disorders and Stroke
National
Institutes of Health (NIH) National
Multiple Sclerosis Society US
Department of Heath and Human Services
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