Injected Into Woman with MS
|Updated: Tue, Jul 24 1:24 PM EDT
By Merritt McKinney
NEW YORK (Reuters Health) - In an experimental
procedure that holds promise as a treatment for multiple sclerosis (MS)
and other diseases that ravage the central nervous system, researchers
have transplanted nerve cells into the brain of a woman with MS.
The degenerative neurological disease MS is one of
30 to 40 diseases that destroy myelin, the insulation that covers nerve
fibers, according to the principal investigator of the experimental
treatment, Dr. Timothy Vollmer of Yale University School of Medicine in
New Haven, Connecticut. Without the protective sheath of myelin, nerve
fibers have a hard time communicating, he told Reuters Health in an
"The fibers tend to short out
electrically," he explained. "That's what causes the
MS destroys cells called oligodendrocytes, which
produce the myelin that covers nerve fibers in the brain and spinal
cord. But the myelin that protects peripheral nerves, which are found in
other parts of the body, is produced by cells called Schwann cells,
which elude the attack of MS. In animal studies, Schwann cells have been
able to fill in for destroyed oligodendrocytes to produce myelin for the
brain and spinal cord.
Last week, Vollmer and his colleagues tested the
approach in a woman with MS. On July 17 they removed a nerve from the
patient's ankle. The next day, after isolating Schwann cells from the
nerve, they injected the cells into the woman's brain in a technique
called stereotactic surgery.
After spending a day in the intensive care unit for
observation, the woman is doing well and should be going home from the
hospital soon, Vollmer said.
It will be a while, however, before the researchers
will know whether the transplant was a success, according to Vollmer.
"We'll prove that by studying the patient very
carefully," he said.
Six months from now the researchers will use MRI
scans to look for signs that the Schwann cells have survived and grown
to produce myelin. In case the growth is not extensive enough to show up
on the MRI, however, Vollmer's team will take a small biopsy from the
brain to see whether the cells have survived and produced myelin.
Even if the transplant proves to be successful,
"it's not likely to result in major improvement in the patient's
function," Vollmer noted. He explained that Schwann cells were
transplanted to a site of MS damage, or lesion, in the brain that is not
the major source of symptoms. Because the goal of this phase of the
study is to make sure that the procedure is safe and to determine
whether transplanted cells can survive, Vollmer and his colleagues chose
the "safest" area of the brain.
If the procedure does pass the first round of tests
in this patient and a handful of others, Vollmer said the team hopes to
transplant the cells into the types of brain lesions that cause most of
the disability in MS patients. Eventually, they may try to transplant
other types of myelin-growing cells to see whether they improve symptoms
in MS and other myelin destroying diseases, Vollmer said.
"We're obviously very cautious, but we're
trying to lay a very strong scientific foundation," the researcher