March 29, 2010 - New study findings may soon revolutionize multiple
sclerosis (MS) treatment and diagnosis.
The study strongly suggests that there are two major types of MS and that a
simple blood test can tell one from the other. By itself, that would be a major
finding. But that's not all.
One type of MS responds to beta interferon, generally considered the best
treatment. The other type does not -- and beta interferon treatment may even
make it worse, find Stanford University researcher Lawrence Steinman, MD, and
"I'm very excited about some of the implications of this," Steinman tells
WebMD. "The most important implication is that a simple blood test could tell
us who does and does not respond to beta interferon. It could be that
about 25% of patients are in
the 'do not benefit' group."
For patients who do respond to beta interferon, the study raises hopes that
the drug may work better than previously thought. That's because the clinical
trials that proved beta interferon to be effective likely enrolled both types
of MS patients, watering down the drug's average efficacy in beta interferon responders.
In coming months, Steinman said, he hopes to show that the two kinds of MS
respond differently to other MS drugs, too.
Patricia O'Looney, PhD, vice president for biomedical research at the
National MS Society, said the study will help researchers solve some of the
mysteries surrounding MS.
"No two people with MS are exactly alike in disease course and in response
to therapy. Why is this?" O'Looney tells WebMD. "We don't understand why
about 50% of people who take
beta interferon don't respond well."
Multiple sclerosis is an autoimmune disease caused by haywire immune
responses that attack the myelin sheath protecting nerve fibers in the central
nervous system. The culprits are lymphocytes called CD4 T helper cells,
sometimes called the quarterbacks of the immune system.
In MS, a subset of CD4 cells called Th1 cells direct an inflammatory immune
response against myelin. Beta interferon dampens this signal, so it's a great
help to people with MS -- at least, to those who respond to treatment.
Why doesn't beta interferon always work for MS patients? A clue comes from a
little known but equally devastating disease called neuromyelitis optica (NMO).
In NMO, the immune system attacks nerve fibers, but it targets a protein
different from myelin, says NMO researcher Michael
R. Yeaman, PhD, vice chair of medical sciences at Harbor-UCLA Medical
NMO researchers have shown that the CD4 cells behind NMO aren't Th1 cells,
but another type called Th17. Might Th17 cells cause some cases of MS?
Yes, Steinman and colleagues found. First the researchers induced an MS like
disease in mice using either autoimmune Th17 or autoimmune Th1 cells. Then they
showed that beta interferon improved MS-like symptoms in mice with Th1-induced
disease, but that the drug worsened MS symptoms in mice with Th17-induced