Credit: Chad McNeeley
Children with severe combined immune deficiency (SCID) have a good chance of survival if they undergo hematopoietic stem cell transplant (HSCT) within 3.5 months of birth, a new analysis suggests.
The risk of death is also lower if patients are free of infection at transplant and have a matched sibling donor.
“Survival is much, much better if infants undergo transplant before they turn 3.5 months old and before they contract any SCID-related infections,” said Sung-Yun Pai, MD, of the Dana-Farber Cancer Institute in Boston.
This underlines the importance of screening newborns for SCID, she added.
Dr Pai and her colleagues expressed this viewpoint, and detailed the research to support it, in The New England Journal of Medicine.
The team analyzed data on 240 children with SCID who were transplanted at 25 centers across North America between January 1, 2000, and December 31, 2009, (before the US Department of Health and Human Services recommended newborn screening for SCID in 2010).
The researchers assessed the patients’ outcomes according to age, infection status, donor source, and conditioning regimen.
Results revealed that children who underwent transplant before 3.5 months of age had excellent survival, regardless of donor source or infection status, as did patients with a matched sibling donor.
Children transplanted after 3.5 months also had a high survival rate regardless of donor source, as long as they did not have an active infection at the time of transplant.
Overall, 74% of patients survived at least 5 years. The 5-year survival rate was 97% in patients with a matched sibling donor, 94% among patients transplanted within 3.5 months of birth, 90% among patients who never had an infection, and 82% in patients whose infection resolved before transplant.
Survival was low—50%—among patients who were older than 3.5 months and had active infections at the time of transplant.
Actively infected infants who did not have a matched sibling donor and received immunosuppressive therapy or chemotherapy before transplant had particularly poor survival as well, ranging from 39% to 53%.
“This study accomplishes several things,” Dr Pai said. “First, it creates a baseline with which to compare patient outcomes since the advent of newborn screening for SCID. Second, it provides guidance for clinicians regarding the use of chemotherapy conditioning before transplantation.”
“Third, it highlights the relative impacts of infection status and patient age on transplant success. Lastly, it establishes the importance of early detection and transplantation, which points to the benefit of expanding newborn screening for SCID as broadly as possible.”
