Newborn Screening for Severe Combined Immunodeficiency: Do Preterm Infants Require Special Consideration?

Anne E Atkins; Michael F Cogley; Mei W Baker

doi:10.3390/ijns7030040

Newborn Screening for Severe Combined Immunodeficiency: Do Preterm Infants Require Special Consideration?

Int J Neonatal Screen. 2021 Jul 8;7(3):40. doi: 10.3390/ijns7030040.

Authors

Anne E Atkins¹, Michael F Cogley¹, Mei W Baker^{1

2

3}

Affiliations

¹ Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA.
² Genetics and Metabolism Division, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA.
³ Center for Human Genomics and Precision Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA.

Abstract

The Wisconsin Newborn Screening (NBS) Program began screening for severe combined immunodeficiency (SCID) in 2008, using real-time PCR to quantitate T-cell receptor excision circles (TRECs) in DNA isolated from dried blood NBS specimens. Prompted by the observation that there were disproportionately more screening-positive cases in premature infants, we performed a study to assess whether there is a difference in TRECs between full-term and preterm newborns. Based on de-identified SCID data from 1 January to 30 June 2008, we evaluated the TRECs from 2510 preterm newborns (gestational age, 23-36 weeks) whose specimens were collected ≤72 h after birth. The TRECs from 5020 full-term newborns were included as controls. The relationship between TRECs and gestational age in weeks was estimated using linear regression analysis. The estimated increase in TRECs for every additional week of gestation is 9.60%. The 95% confidence interval is 8.95% to 10.25% (p ≤ 0.0001). Our data suggest that TRECs increase at a steady rate as gestational age increases. These results provide rationale for Wisconsin's existing premature infant screening procedure of recommending repeat NBS following an SCID screening positive in a premature infant instead of the flow cytometry confirmatory testing for SCID screening positives in full-term infants.

Keywords: T-cell receptor excision circles (TRECs); gestational age; newborn screening (NBS); premature newborns; severe combined immunodeficiency (SCID).