UCLA physicians announced today that three young boys - each born with a defective immune system like the "boy in the bubble" - underwent umbilical-cord blood transplants from unrelated donors, and two years later, are seemingly cured of their immunodeficiencies.
Banked unrelated umbilical-cord blood, matched at five out of six potential match sites, was used to reconstitute the defective immune systems of two brothers with X-linked lymphoproliferative syndrome (XLP) and one boy with X-linked hyper-IgM immunodeficiency (XHIM). Two years post-transplant, all three patients have normal immune systems, according to a UCLA study published in the April issue of The Journal of Pediatrics.
"Both these genetic disorders have a poor, long-term survival rate, even though the children were doing well on immunoglobulin treatment at the time of the transplants," said Dr. E. Richard Stiehm, professor of pediatrics and chief of pediatric immunology, allergy and rheumatology at the Mattel Children's Hospital at UCLA and the study's lead author. "Most children born with these immune deficiencies die at an early age and nearly all succumb in young adulthood."
According to UCLA doctors, one in every 10,000 babies is born with an immunodeficiency and one in every 100,000 babies is born with severely compromised immune systems. In general, the disorder affects boys more than girls.
The two brothers - Blayke, age 8 months, and Garrett LaRue, age 4 - suffered from XLP, which destroys the body's immune system, when they contracted Epstein-Barr virus, the virus that causes infectious mononucleosis. The LaRue family discovered that their sons were afflicted with XLP in 1994 after one of their sons, Layne, died suddenly of hepatitis due to Epstein-Barr virus.
"In two weeks the virus destroyed Layne's immune system," said Theresa LaRue, the boys' mother. "We then tested our three boys and found that two were affected with XLP."
In cases such as the LaRues', the first option commonly explored by doctors is a bone-marrow transplant, which was the only potential curative treatment.
However, the results of these three cases prove that umbilical-cord transplant is a viable option. By using healthy white blood cells from the umbilical cord instead of bone-marrow cells,
the immune system can also return to its normal, healthy state, Stiehm said. In XLP, cord blood is particularly valuable since it is never infected with Epstein-Barr virus "We completely eliminated the defective immune system through chemotherapy and replaced it with a healthy child's immune system," Stiehm said. "With umbilical-cord blood, we transplant another baby's immune system into the sick child's body."
According to UCLA doctors, the advantages of umbilical-cord transplant over either related or unrelated bone marrow are:
-- Less graft vs. host disease - umbilical cord blood has not been exposed to outside antigens so the chance of graft vs. host disease is less. Graft vs. host disease is caused by incompatibility between the transplanted cells and their new host; the grafted cells reject their new host, causing a number of complications including death.
-- Rapid availability - it is often difficult to find a compatible donor who is willing to undergo the needle aspirations under anesthesia involved in a bone marrow transplant. Unrelated cord blood cryopreserved in a cord blood bank is available for transplantation within two weeks of donor identification.
-- Ease - harvesting cord blood is a painless, noninvasive procedure with no risk to the newborn.
-- Works with a less-than-perfect match - the degree of histoincompatibility that can be tolerated is greater with cord blood than with bone marrow.
The third patient, 11-year-old Billy Bodine, also underwent an unrelated cord blood transplant. UCLA doctors say he is doing very well and no longer requires immune globulin infusions to boost his immune system.
"It's amazing to think that when a baby is born, a new life comes into the world along with a chance to save other lives," LaRue said. UCLA doctors and the parents of Blayke, Garrett and Billy encourage parents-to-be to consider donating the umbilical-cord blood of their new baby to a designated cord blood bank.
UCLA received $10 million from the National Institutes of Health to set up the UCLA umbilical-cord blood bank, part of a national program designed to fully investigate the efficacy and viability for making this procedure available on a national level. UCLA was also chosen as a site to encourage minority donors to donate, thus increasing the donor-pool matching potential.
In addition to Stiehm, others who collaborated on the research include Ulrike H. M. Ziegner, Carolyn Schanen, Dr. Stephen A. Feig, Dr. Mary Wakim, Robert L. Roberts, Dr. David J. Rawlings, Dr. Sinisa Dovat and John K. Fraser, all members of the Mattel Children's Hospital at UCLA and the UCLA School of Medicine; Dr. Hans D. Ochs, Dr. Kuniaki Seyama and Dr. Takeshi Futatani, of the University of Washington School of Medicine, Seattle, Wash.; and Dr. Thomas Gross of Children's Hospital Medical Center, Cincinnati, Ohio.
Support was provided by the Immune Deficiency Foundation, William C. Havens XLP Research Fund, Joan J. Drake grant for Cancer Research, National Institutes of Health grants, the American Cancer Society, a Pennington Research Award and UCLA's Jonsson Comprehensive Cancer Center.
Materials provided by University Of California, Los Angeles Health Sciences. Note: Content may be edited for style and length.
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