TREC and KREC in very preterm infants: reference values and effects of maternal and neonatal factors

T-cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) assays have been used for severe combined immunodeficiencies newborn screening (NBS). We assessed TREC and KREC NBS values in preterm infants and investigated if perinatal characteristics affect their values. We performed a retrospective study collecting data from TREC and KREC NBS database and from mothers’ and infants’ medical charts. TREC and KREC values were lower in preterm infants born at 23–31 or 32–36 weeks of gestation than in term infants. Gestational age <28 weeks of gestation, leukopenia, and hypertensive disorders of pregnancy lowered TREC. Hypertensive disorders of pregnancy lowered KREC and intrapartum fever >38 °C increased it. Low TREC and KREC values were not associated to the risk of developing early-onset sepsis and late-onset sepsis. TREC and KREC levels are lower in preterm than term infants, but this did not increase the risk of neonatal sepsis.

T细胞受体切除环（T-cell receptor excision circles, TREC）与κ删除重组切除环（kappa-deleting recombination excision circles, KREC）检测已被应用于重症联合免疫缺陷的新生儿筛查（NBS）。本研究针对早产儿的TREC与KREC新生儿筛查结果展开评估，并探究围产期特征是否会对上述检测值产生影响。我们通过调取TREC与KREC新生儿筛查数据库及母婴病历资料开展了一项回顾性研究。相较于足月新生儿，孕23~31周或32~36周分娩的早产儿其TREC与KREC检测值更低。孕周＜28周、白细胞减少症以及妊娠期高血压疾病会导致TREC水平降低；而妊娠期高血压疾病会使KREC水平下降，产时发热＞38℃则会升高KREC水平。低TREC与KREC检测值与早发性脓毒症、晚发性脓毒症的发病风险并无关联。综上，早产儿的TREC与KREC水平低于足月儿，但这并未增加新生儿脓毒症的发病风险。