Predictors for T cell receptor excision circles in infants without severe combined immunodeficiency or thymic aplasia/hypoplasia.

BACKGROUND

Although developed to identify severe combined immunodeficiency (SCID), T cell receptor excision circle (TREC)-based newborn screening also detects T cell lymphopenia of varying etiologies.

OBJECTIVE

To identify perinatal factors associated with abnormal TRECs in infants without SCID or thymic aplasia/hypoplasia.

METHODS

Newborns (birthdates: October 2011-December 2021) with abnormal TRECs, without SCID or thymic aplasia/hypoplasia, were compared with normal TREC controls matched for gestational age, birthweight, and neonatal intensive care unit status.

RESULTS

A total of 949 infants had abnormal TRECs. After excluding 62 infants with SCID or thymic aplasia/hypoplasia, 887 cases were matched to 2661 controls. Logistic regression revealed that male sex (odds ratio [OR] 1.75, 95% CI: 1.49-2.05), meconium-stained amniotic fluid (OR 1.78, 95% CI: 1.28-2.48), history of transfusion (OR 1.75, 95% CI: 1.42-2.03), lower 5-minute APGAR scores (OR 0.84, 95% CI: 0.81-0.87), and prepregnancy diabetes (OR 1.75, 95% CI: 1.10-2.72) were most predictive of abnormal TRECs. Black infants (49.2% vs 34.2%, P < .001) and infants of black mothers (38.1% vs 30.7%; P < .001) had significantly higher rates of abnormal TRECs compared with controls. Maternal alcohol and cigarette use, prepregnancy and gestational hypertension, and intrapartum steroid use did not significantly differ between the abnormal TRECs and control groups.

CONCLUSION

Male sex, meconium-stained amniotic fluid, transfusion history, lower 5-minute APGAR scores, and prepregnancy diabetes were most predictive of abnormal TRECs in non-SCID/thymic aplasia/hypoplasia infants. Maternal alcohol/cigarette use, hypertension, or steroid use, while related to perinatal stress, were not associated with abnormal TRECs. Black infants had a higher rate of abnormal TRECs compared with controls, highlighting potential health disparities.