Screening newborns for severe combined immunodeficiency — SCID, sometimes referred to as “bubble boy disease” — significantly increases survival rates, researchers say.
Infants with SCID appear healthy at birth, but have no immune defenses, making them highly susceptible to severe and often fatal infections. The 1976 TV movie “The Boy in the Plastic Bubble” promoted awareness of the rare disorder.
Identifying and treating SCID before the infections can occur can be lifesaving, according to the new study.
Researchers found that widespread screening increased the five-year survival rate of children with the disorder from 73% to 87%. Among children who had SCID diagnosed early because of the screening, and not because of illness or family history, 92.5% survived five or more years after they started treatment.
The study was conducted by the U.S. National Institute of Allergy and Infectious Diseases and colleagues.
“This study definitively shows that population-wide newborn screening for SCID has made it possible to save the lives of many more children with the disorder than ever before,” said Dr. Hugh Auchincloss, acting director of the NIAID.
“We hope these findings will encourage more countries to screen newborns for this devastating disease,” he said in an agency news release.
Each year in the United States and Canada, between 40 and 80 babies are diagnosed with SCID, which is caused by gene mutations.
U.S. National Institutes of Health scientists developed a newborn screening test for SCID in 2005.
By 2018, all U.S. states, Washington D.C. and two U.S. territories were screening newborns. Seven Canadian provinces and territories also screen newborns.
Kids with SCID usually die within the first year or two of life unless they receive an immune-restoring treatment, which can be a stem-cell transplant, gene therapy or enzyme therapy.
To study the impact of screening, investigators analyzed data on more than 900 children with SCID who received a transplant of blood-forming stem cells from a non-genetically matched donor between 1982 and 2018.
The researchers then examined the five-year overall survival rate of these children from 2010 to 2018, when newborn screening was in effect at participating sites and compared this to earlier time periods.
Those who received their transplants from genetically matched sibling donors were excluded from the analysis because they had high overall survival rates throughout the study period.
Despite advances in clinical care, survival of those who received a stem-cell transplant from a non-genetically matched donor remained steady at 72% to 73% from 1982 to 2009. But it increased to 87% during the years 2010 to 2018, when screening was undertaken.
Previous research had shown that being younger than 3.5 months at the time of transplant and not having an active infection at that time improves survival, and an analysis of the data showed that both these factors were much more common in the era of newborn screening. This drove the survival increase, according to the study. The number of babies with SCID who had never had an infection by the time of transplant was dramatically higher, which also helped survival.
The study findings were published June 20 in The Lancet. The NIH and its agencies funded the study.
The Children’s Hospital of Philadelphia has more on severe combined immunodeficiency.
SOURCE: U.S. National Institute of Allergy and Infectious Diseases, news release, June 20, 2023
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