newborn screening immunoassay
Dried blood spot test measuring T-cell receptor excision circles to detect severe combined immunodeficiency in newborns.
Full Definition
Newborn screening immunoassay refers to the population-based testing program that uses dried blood spots collected on filter paper to measure T-cell receptor excision circles (TRECs) as a marker of T-cell production. This screening method can detect severe combined immunodeficiency and other severe T-cell lymphopenias before clinical symptoms appear, enabling early intervention. The assay uses quantitative PCR to measure TREC levels, with low or absent TRECs indicating impaired thymic output. Abnormal results require confirmatory testing with flow cytometry and additional immunologic evaluation.
Usage
Usage note: Part of expanded newborn screening programs; measures TRECs as surrogate for T-cell production.
In Context
- "The newborn screening immunoassay detected low TRECs, prompting urgent immunologic evaluation." — Screening report
- "Implementation of newborn screening immunoassay has enabled early detection of SCID before life-threatening infections occur." — Public health report