Umbilical Artery Leucine‐Rich α‐2 Glycoprotein as a Predictor of Bronchopulmonary Dysplasia in Preterm Infants

Introduction Leucine‐rich α‐2 glycoprotein (LRG) is an acute‐phase reactant protein which reflects inflammation differently from C‐reactive protein. We investigated the value of cord blood LRG levels for predicting bronchopulmonary dysplasia (BPD) in preterm infants. Methods This prospective cohort study included 64 infants born at 22–31 weeks' gestation (22 and 42 in the BPD and non‐BPD arms, respectively), and between‐group comparisons of LRG and interleukin (IL)‐6 levels in the cord blood, neonatal LRG, and immunoglobulin (Ig)M were undertaken. Accounting for gestational age, inverse probability weighted generalized estimating equation assessed the biomarkers' independent effects on BPD. Results In the BPD group, the incidences of histological chorioamnionitis, funisitis, neonatal steroid treatment, and ventilator duration were significantly higher ( p = 0.023, 0.043, 0.011, and < 0.001, respectively) whereas the Apgar score 1st minute, 5th minute, birthweight, and gestational age were significantly lower ( p = 0.001, 0.011, < 0.001, < 0.001, respectively). After adjustment, umbilical artery (UA)‐LRG (odds ratio [OR]: 2.678, 95% confidence interval [CI]: 1.225–0.5.857; p = 0.014) and umbilical vein (UV)‐IL‐6 (OR: 1.258, 95% CI: 1.020–1.552; p = 0.032) remained independent risk factors for BPD, whereas UV‐LRG, UA‐IL‐6, IgM, and neonatal‐LRG showed no significant associations. Conclusions UA‐LRG may serve as a biomarker for predicting BPD and identify infants who are at a higher risk of BPD and could benefit more from corticosteroids or other therapies. UA‐LRG's superior predictive accuracy over UV‐LRG is attributable to the fact that cytokines in the amniotic fluid might cause fetal inflammation in utero before the development of histologically chorioamnionitis.