Systematic evidence review of newborn screening and treatment of severe combined immunodeficiency.

CONTEXT: Severe combined immunodeficiency (SCID) is a group of disorders that leads to early childhood death as a result of severe infections. Recent research has addressed potential newborn screening for SCID.

OBJECTIVE: To conduct a systematic review of the evidence for newborn screening for SCID, including test characteristics, treatment efficacy, and cost-effectiveness.

METHODS: We searched Medline and the OVID In-Process & Other Non-Indexed Citations databases. We excluded articles if they were reviews, editorials or other opinion pieces, or case series of fewer than 4 patients or if they contained only adult subjects or nonhuman data. The remaining articles were systematically evaluated, and data were abstracted by 2 independent reviewers using standardized tools. For topics that lacked published evidence, we interviewed experts in the field.

RESULTS: The initial search resulted in 719 articles. Twenty-six met inclusion criteria. The results of several small studies suggested that screening for SCID is possible. Interviews revealed that 2 states have begun pilot screening programs. Evidence from large case series indicates that children receiving early stem-cell transplant for SCID have improved outcomes compared with children who were treated later. There is some inconclusive evidence regarding the need for donor-recipient matching and use of pretransplant chemotherapy. Few data on the cost-effectiveness of a SCID-screening program.

CONCLUSIONS: Evidence indicates the benefits of early treatment of SCID and the possibility of population-based newborn screening. Better information on optimal treatment and the costs of treatment and screening would benefit policy makers deciding among competing health care priorities.