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Updated: Mar 10, 2026
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
Newborn screening for severe combined immunodeficiency using a novel and simplified method to measure T-cell excision
Laura Tagliaferri1, Joachim B Kunz2, Margit Happich2
1Department of Pediatric Oncology, Hematology and Immunology, Children's Hospital, University of Heidelberg, Heidelberg, Germany; Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca'randa, Ospedale Maggiore Policlinico, Milan, Italy.
Insights
Early diagnosis of severe combined immunodeficiency (SCID) is crucial. A new, cost-effective newborn screening method using T-cell receptor excision circles (TRECs) offers high sensitivity and specificity for timely SCID detection.
Area of Science:
- Immunology
- Genetics
- Pediatrics
Background:
- Severe combined immunodeficiency (SCID) requires early diagnosis and treatment for favorable outcomes.
- Current SCID newborn screening methods can be complex and costly.
Purpose of the Study:
- To develop and validate a simplified, economical newborn screening method for SCID.
- To quantify T-cell receptor excision circles (TRECs) using qPCR on dried blood spots (DBSs).
Main Methods:
- Established a quantitative PCR (qPCR) method for TREC quantification on DBSs.
- Validated the method with 11 SCID positive controls (TREC-negative).
- Screened 6034 anonymized newborns, analyzing TREC levels.
Main Results:
- The method demonstrated 100% sensitivity with positive controls.
- 99.95% of screened newborns had normal TREC levels (median 600 TREC copies/1.6mm punch).
- Achieved a low recall rate of 0.05%.
Conclusions:
- The developed TREC quantification method is highly sensitive, specific, and cost-effective for SCID newborn screening.
- This simplified method requires less input material and no DNA purification, reducing time and costs.
- This approach is suitable for widespread implementation in newborn screening programs.
Abstract:
The prognosis of children with severe combined immunodeficiency (SCID) depends on a presymptomatic diagnosis and early treatment before complications occur. We established and tested a simplified, practical and economic newborn screening method based on the quantification of T-cell receptor excision circles (TRECs) on dried blood spots (DBSs) through qPCR. Our method was validated by the analysis of 11 positive controls, which all showed an absence of TRECs, thus yielding a sensitivity of 100%. Further, we analyzed 6034 anonymized newborns of whom 6031 (99,95%) showed a normal TREC qPCR with a median of 600 estimated TREC copies/1.6mm punch. The test showed a recall-rate of 0.05%. We present a highly sensitive, specific and time- and cost-effective method of TREC quantification, which is suitable for SCID newborn screening. In comparison to established methods, our test requires only 25% of the input material, doesn't require DNA purification and significantly reduces time and cost requirement.
