Better Treatment: Defect No Longer Means Life in a Bubble

Better Treatment: Defect No Longer Means Life in a Bubble

By Janice Gaston, Winston-Salem Journal, N.C.

Dec. 26–Children with severe combined immunodeficiency, also known as SCID, no longer have to grow up in a bubble, the way that one of its best-known victims did.

David Vetter of Houston, who died at 12 in 1984, made headlines in the 1970s. The public learned then of his rare genetic illness, which left him so vulnerable to germs that he was forced to spend his life in a sterile plastic enclosure. His story inspired a PBS documentary and a made-for-TV movie, The Boy in the Plastic Bubble, starring John Travolta.

SCID causes a defect in the white blood cells that ward off viruses, bacteria and fungi.

Doctors now know that SCID can be the result of a mutation in one of at least 12 genes. And they have weapons with which to fight it, most notably, bone-marrow transplants.

Dr. Rebecca Buckley, a professor of pediatrics and immunology at Duke University School of Medicine, has led the fight against SCID for nearly 25 years. Luke Pennell, a SCID baby from Yadkinville, is one of her patients. Under her guidance, 157 children have had bone-marrow transplants at Duke, and 123 of them are still alive. Left untreated, most SCID babies die before the age of 1.

“We have many who are in their teens or early 20s,” Buckley said. Duke has the only program of its kind in North Carolina and is one of only two hospitals in the country that do bone-marrow transplants for children who don’t have a perfectly matched sibling. Luke has no full siblings. His mother proved to be his closest match, and she provided the bone marrow for his transplant.

SCID can be inherited in two ways, Buckley said. The most common type of SCID, X-SCID, is inherited from the mother and affects only boys. Both parents have to carry the defective gene to produce the other types.

Luke has a less common form of SCID, one that affects only 5 percent of SCID children, his mother said.

Some experts think that SCID is as rare as one case in 500,000 births. But Buckley thinks that the condition is much more common. The genetic defect can be detected through a blood test, but newborns usually are not tested for it unless they have a family history of the disease. Babies who die of severe infections could be victims of undetected SCID, she said.

“Remember, when these babies are first born, they look perfectly normal,” Buckley said. “We’ve had a number who looked like the Gerber baby. They’re fine until they get sick with very bad viruses.” Children with SCID have frequent, severe and hard-to-treat infections. Many, like Luke, don’t gain weight as they should.

Three of the most dangerous viruses that these babies face are Epstein-Barr, or EBV, which causes mononucleosis; adenovirus, which affects the respiratory and intestinal tracts; and cytomegalovirus, or CMV, which can cause hearing and vision loss, seizure and death.

Many people carry the CMV and EBV viruses in their bodies, but those with normal immune systems aren’t harmed by them.

Buckley is lobbying to have newborns screened. “We have been able to transplant 45 babies in the first three months. Ninety-six percent of those are surviving. If you wait beyond that time, they usually come in with a bad infection.”

Treating babies early is far less expensive, too. The bone-marrow procedure, including expenses for the parents, can be done for less than $100,000 if the baby is treated soon after birth. But once the baby starts developing severe infections and spending lots of time in the hospital, medical bills can top $1 million.

The breakthrough in treating SCID came in the early ’80s, Buckley said. Babies usually receive a bone-marrow transplant from a parent, who can provide stem cells that can develop into healthy blood cells in the baby. The babies receive the cells slowly through a syringe.

“Ninety to 120 days after the transplant, stem cells are transformed into T-cells, which come out and protect the patient,” Buckley said. T-cells are white blood cells that help protect the body against infection.

She has watched some of the babies she has treated graduate from college, go to medical school, earn an MBA.

“They’re leading normal lives,” she said. She expects the same for Luke Pennell.

“I used to see these babies die all the time,” she said. “Now it’s just wonderful to be able to see them make it and grow up and be normal.”

–Janice Gaston can be reached at 727-7364 or at jgaston@wsjournal.com.

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