ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Thursday, December 12, 1996 TAG: 9612120025
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
SOURCE: Knight-Ridder/Tribune
MEMO: NOTE: A different version by AP ran in the New River edition.
A fetus with a weak immune system was healed by a bone marrow transplant
Five months before he was born, Taylor Dahley made medical history by receiving a bone marrow transplant that repaired his catastrophically weak immune system.
Now a healthy 17-month-old toddler, Taylor shows no signs of the rare genetic malady, called severe combined immune deficiency syndrome, or SCIDS, the same disease that killed his brother in infancy and forced David, the famous ``bubble boy,'' to spend his short life in a sterile plastic tent, unable even to touch his parents.
Taylor has suffered nothing worse than a couple of colds and a flu.
``He's essentially cured of his disease. I'm very confident that he will have a normal life,'' said Alan Flake, the pediatric surgeon who performed the transplant.
Flake, who recently joined Children's Hospital of Philadelphia, now hopes to use the prenatal procedure for many other life-threatening, hard-to-treat diseases.
``A whole host of immune-deficiency disorders and blood diseases could be treated this way,'' he said.
Among them is sickle cell anemia, which affects about 150 of every 100,000 black children born in this country.
The prenatal transplant procedure, developed and used by Flake at Wayne State University in Detroit, is described in today's New England Journal of Medicine. It is another milestone in the growing field of fetal surgery, in which anatomical or blood defects are corrected before birth.
Bone marrow is the body's factory for infection-fighting blood cells. SCIDS babies fail to make T-cells, a type of white blood cell that is essential for warding off infection.
In recent years, healthy bone marrow from donors has been transplanted into babies with SCIDS or other diseases a few months after birth, but the procedure is risky. In some cases, the newborn's defective marrow must first be chemically destroyed to prevent rejection of, and make space for, the donated cells. This leaves the baby temporarily defenseless against infection.
The survival rate is 60 percent to 90 percent, depending on how closely the donated marrow matches.
David, the ``bubble boy'' who spent his life inside a germ-free plastic tent, died in 1984 at age 12 after such an attempt.
Transplantation before birth offered crucial advantages, Flake explained.
Because Taylor's immune system was not mature, he did not reject the marrow cells donated by his father, Brian, who was not an identical match. Taylor's developing bones also had the necessary sites for the cells to take hold. And since he was in his mother's protective womb, he did not need to be placed in isolation for four months while the new marrow became functional.
The fetus received three doses of marrow beginning at 16 weeks of gestation - when it was about 6 inches long. Flake used a long needle guided by ultrasound to inject the marrow cells into the fetus's abdomen.
Each injection, and the genetic test used to diagnose the disorder, carried a small risk of miscarriage.
The biggest hurdle, Flake said, was preventing the father's mature marrow from attacking the fetus's immature marrow. Flake processed the donated marrow to eliminate mature cells and multiply immature ones, called stem cells, which later develop into all types of blood cells.
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