Serum neutrophil gelatinase-associated lipocalin as a predictor of the development of bronchopulmonary dysplasia in preterm infants.

ABSTRACT

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a chronic lung disease mostly occurring in preterm infants. The pathogenesis of BPD involves early inflammation and remodeling of the premature lung. AIM: To search for the novel predictive marker of BPD development, we studied serum levels of neutrophil gelatinase-associated lipocalin (NGAL), an innate immune mediator, in preterm infants. METHODS: Serum NGAL concentrations at birth were measured by enzyme-linked immunosorbent assay. The reference levels were determined in 52 infants having no anomalies or inherited diseases. The levels and clinical variables were assessed in association with BPD. RESULTS: Geometric means (95%CI) of serum NGAL levels at birth of infants having no underlying diseases were 32.4 (22.1-47.5), 58.6 (47.9-71.8), and 126.2 (99.0-168.7) ng/mL for <31, 31-36 and >36 gestational weeks (GW), respectively (p<0.001). These levels positively correlated with neutrophil (p<0.0001) or monocyte counts (p<0.0001). The median NGAL levels (307.8 ng/mL) and neutrophil counts (4141/µL) at birth of 16 preterm infants (<31 GW) who developed BPD were higher than those (42.9 ng/mL and 1357/µL) of 20 infants (<31 GW) who did not (p<0.0001 and p=0.012), respectively. In multivariable analysis for 36 infants born less than 31 GW, higher NGAL levels (≥ 82 ng/mL) but not neutrophil counts at birth had a significant association with developing BPD (gestational-age adjusted odds ratio [OR]=37.45 [3.08-455.49], p<0.01). CONCLUSIONS: High serum levels of NGAL at birth could be an early sensitive marker for BPD in preterm infants, because their levels were physiologically low.