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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.