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Simultaneous Quantification of T-Cell Receptor Excision Circles (TRECs) and K-Deleting Recombination Excision Circles (KRECs) by Real-time PCR
Published on: December 6, 2014
Neonatal screening for severe combined immunodeficiency
1Department of Pediatrics, University of California San Francisco, UCSF Benioff Children's Hospital, San Francisco, California, USA. puckj@peds.ucsf.edu
Insights
Newborn screening for severe combined immunodeficiency (SCID) using T-cell receptor excision circle (TREC) testing is successfully integrated into public health programs. Early detection enables prompt treatment, improving outcomes for infants with SCID and related disorders.
Area of Science:
- Immunology
- Genetics
- Public Health
Background:
- Severe combined immunodeficiency (SCID) is a group of rare genetic disorders characterized by profound defects in T-cell immunity.
- Early detection and treatment of SCID are critical to prevent life-threatening infections and improve long-term outcomes.
- Population-based newborn screening programs are expanding to include SCID and related disorders.
Purpose of the Study:
- To review the rationale, development, and implementation of SCID newborn screening programs.
- To highlight current and future challenges in SCID screening and management.
- To assess the effectiveness of T-cell receptor excision circle (TREC) testing in identifying infants with SCID.
Main Methods:
- Review of existing literature and data on SCID newborn screening programs.
- Analysis of early results from pilot states utilizing TREC testing.
- Evaluation of the clinical validity and utility of TREC as a biomarker for T-cell lymphopenia.
Main Results:
- TREC testing has been successfully integrated into state public health newborn screening panels.
- TREC testing demonstrates clinical validity as a biomarker for impaired T-lymphocyte production or increased loss.
- Pilot programs have successfully detected SCID and other T-cell lymphopenic disorders, enabling timely referrals for treatment.
Conclusions:
- Routine newborn screening for SCID using TREC testing facilitates presymptomatic diagnosis.
- Integrated public health programs can effectively implement TREC-based SCID screening.
- Prompt diagnosis and treatment of SCID and related disorders lead to improved patient outcomes and a better understanding of these conditions.
Purpose Of Review:
Population-based newborn screening for severe combined immunodeficiency (SCID) and related disorders has been instituted in five states, with several more planning to add this testing to their newborn screening panels. This review summarizes the rationale, development and implementation of SCID screening programs to date and highlights current and future challenges.
Recent Findings:
Early results of T-cell receptor excision circle (TREC) testing newborns in pilot states indicate that this addition to the newborn screening panel can be successfully integrated into state public health programs. The TREC test has clinical validity and TRECs, as predicted, are an excellent biomarker of poor T lymphocyte production in the thymus or increased lymphocyte loss resulting in T-cell lymphopenia. A variety of cases with typical SCID genotypes and other conditions have been detected in a timely manner and referred for appropriate early treatment.
Summary:
Early detection of primary immunodeficiency is recognized as important for avoiding infectious complications that compromise outcomes. Routine screening of all newborns with the TREC test, implemented as part of an integrated public health program, can achieve presymptomatic diagnosis of SCID and other disorders with T-cell lymphopenia, allowing prompt and effective treatment and leading to a better understanding of the spectrum of these disorders and how to manage them.
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