The District of Columbia Department of Health has added Severe Combined Immunodeficiency (SCID) to the standard newborn screening panel. Pediatric Immunologist Michael Keller provides the following information for area resources:
Severe Combined Immunodeficiency (SCID)
SCID is a group of disorders caused by congenital defects in the development or survival of T-lymphocytes. It often manifests in the first few months of life with failure to thrive and severe, recurrent infections. It is almost universally fatal in the first two years of life unless treated via hematopoietic stem cell transplant. If caught in the first few months of life prior to development of significant infections, transplantation is successful in 95% of cases.
Newborn screening for SCID is now being performed via the TREC assay, which has extremely high sensitivity and specificity and uses the standard Guthrie card. This assay detects the presence of T-cell recombination excision circles (TRECs) which are present only in newly developed T-cells, and is thereby a reflection of successful T-cell development and thymic function. Aside from SCID, the TREC assay can also detect several other forms of primary immunodeficiency and secondary causes of profound lymphopenia.
Expedient immunologic evaluation is necessary for any infant with a positive TREC screen in whom SCID is suspected. Lymphocytopenia (ALC <2800 cells/ul in infants) is common but not universal in SCID, and T-cell enumeration by lymphocyte flow cytometry is warranted for confirmation.
Until referral, infants with a positive TREC assay should be strictly shielded from any sick contacts. Live vaccines (Rotateq) should be strictly avoided until the infant is fully evaluated.
Immunology Referral Centers:
Children’s National Medical Center
Brett Loechelt, MD, Director of Immunology Section
Michael Keller, MD
Burcin Uygungil, MD
Johns Hopkins Children’s Center
Howard Lederman, MD PhD
Beth Younger, CNP PhD
O&O ALPAN, LLC: Fairfax, VA
Oral Alpan, MD
University of Virginia Health Center, Charlottesville, VA
Monica Lawrence, MD