Friday, 2/28/97
Umbilical cord cells used to treat disease
Therapy provides convenient alternative to bone marrow
transplants for genetic immune system disorders
By Kathryn Combs
Daily Bruin Contributor
Playfully donning a UCLA cap while squirming in the arms of his
father, 4-year-old Garrett LaRue seemed anxious to get to his
grandmother’s, where he and his family would finally be able to
relax after a series of intense medical therapies.
Garrett had undergone an umbilical cord transplant and was
released from the UCLA Children’s Hospital on Tuesday.
The second of two brothers to receive this type of transplant,
Garrett, like his brother Blayke, suffers from a rare genetic
disease called X-linked lymphoproliferative disease.
XLP is a rare genetic disease that destroys the body’s immune
system and, as a result, patients are unable to fight the onset of
illness. Without proper therapy, individuals with XLP are usually
disabled by the disease before the age of 10.
The LaRue family discovered that their sons were afflicted with
XLP in 1994 when one of their sons, Layne, suddenly died of what
seemed to be complications of mononucleosis.
"In two weeks the virus destroyed his immune system," said
Theresa LaRue, the mother of the two boys.
"We then looked into the disorder and found that they all were
suffering from a problem with their immune systems," La Rue
added.
According to Dr. John Fraser, director of the UCLA umbilical
cord blood bank, the first umbilical cord transplant was performed
in France in 1988, and over the last nine years the procedure has
been performed more than 300 times worldwide.
Bone marrow transplants are commonly used to treat diseases of
the immune system that are genetically based, such as XLP, but can
also be used to treat diseases such as leukemia and aplastic
anemia. In cases such as the LaRues’, the first option commonly
explored by doctors is the bone marrow transplant.
"The bone marrow transplant is the only potential curative
treatment," said Dr. Kathleen Sakamoto of the UCLA department of
pediatric hematology and oncology.
However, Sakamoto said that recent efforts to explore alternate
ways to treat such diseases have spurred interest in the umbilical
cord transplant as an option.
By using healthy white blood cells from the umbilical cord
instead of bone marrow cells, the immune system to return to its
normal, healthy state.
Because umbilical cord transplant is a similar treatment, it can
also be used to treat diseases such as XLP, said Sakamoto.
Umbilical cord transplants, as an option, are attractive for a
number of reasons.
One is that it is often difficult to find a compatible donor
quickly who is willing to undergo the complicated procedure
involved in a bone marrow transplant.
The search for a compatible donor often begins with the
immediate family, because there is a higher chance of finding a
match. However, there is not always a close genetic match between
relatives.
"A child who needs a bone marrow transplant and does not have a
genetic match in their family still needs a transplant. Therefore,
another option for them is to get a umbilical cord blood
transplant," Sakamoto said.
Although the umbilical cord transplant is still in the
experimental stage, early data suggests that there seem to be some
advantages to this procedure.
Sakamoto said because umbilical cord blood has not been exposed
to outside antigens, the chance of "graft vs. host disease" is
less.
Graft vs. host disease is caused by incompatibility between the
transplanted tissue and its new host. It occurs when the grafted
tissue rejects its new host,causing a number of complications which
can include diarrhea or even death, said Sakamoto.
Dr. John Fraser added that other advantages to using umbilical
cord blood are the relative ease of finding a match and nearly
immediate access to the needed material.
"The tissue samples come to my lab where we keep the white blood
cells and freeze them in liquid nitrogen," Fraser said, noting that
because the samples are frozen they can be kept in storage for long
periods of time.
He also said that the samples then stay in the lab, where they
are accessible to any one who needs them, regardless of the current
health status of the original donor. During a bone marrow
transplant, the marrow must be placed within the new host soon
after it is removed from the donor.
This severely limits the possibilities of finding a donor, even
with a national registry of donors.
However, because this procedure has not yet been fully explored
in all its applications, doctors say they are are cautious to
choose one over the other.
"It is to early to see that this procedure is superior to bone
marrow transplants," said Sakamoto.
"It’s another option, I can’t say that absolutely it’s going to
be the best treatment for everyone. There’s a lot that’s unknown
about this procedure, that’s why we are doing these studies now,"
she added.
In September 1996, UCLA received $10 million from the National
Institute of Health to set up the UCLA umbilical cord blood
bank.
This blood bank is part of a national program, sponsored by the
National Institutes of Health, designed to fully investigate the
efficacy and viability for making this procedure available on a
national level. Similar studies are also being done at Duke
University.
But for the LaRue boys, this new procedure seems to have worked
out for the better.
"I know that we still have a long ways to go with Garrett," said
Theresa LaRue, referring to the long series of examinations and
medications awaiting Garrett in the coming months.
"But the last few months have been great. We’re hoping that
Garrett can start school in the fall," she said.
"And as soon as he can limit his clinical visits to once a week
we are going to move home."Garrett LaRue, 4, is released from
UCLA’s Children’s Hospital after receiving an umbilical cord blood
transplant to cure an X-linked lymphoproliferative disease.
Without proper therapy, individuals with XLP are usually
disabled by the disease before the age of 10.