Severe Combined Immunodeficiency
Utility: Confirmatory test of severe combined immunodeficiency (SCID) newborn screening.
Specimen: 1 - 2 mL peripheral blood in sodium heparin (green top).
CPT codes: 86359, 86360, 86355, 86357, 88184, 88185, 81887.
Clinical indication/general description
SCID is characterized by profound impairment of both cellular and humoral immunity due to the absence or markedly diminished number of T cells and variably decreased numbers of B cells or natural killer (NK) cells. Infants affected with SCID typically present within the first year of life with recurrent bacterial and viral infections, opportunistic infections (such as pneumocystis pneumonia), and can have fatal responses to live viral vaccination. SCID is life threatening within the first year of life if not detected and treated with hematopoietic stem cell transplantation. This is a limited assay that only enumerates the numbers of CD4+ T cells, CD8+ T cells, B cells and NK cells. This assay is designed as a confirmatory immunophenotyping for infants who fail the newborn screening program for SCID in the state of Wisconsin.
The assay is designed to enumerate the percent and absolute cell counts of T helper cells (CD3+CD4+), T cytotoxic cells (CD3+CD8+), B cells (CD19+)and NK cells (CD3-CD16+/CD56+). This assay also enumerates the percentage of naïve CD4+ and CD8+ T cells.
Note: The assay should only be ordered for confirmatory immunophenotyping as part of the state of Wisconsin's newborn screening program for SCID.