Pathohistological Changes in the Lungs of Very Preterm Infants with Bronchopulmonary Dysplasia Depending on the Clinical Features.

Abstract

Objective:  Establishing clinical factors associated with histological changes in the lungs of very preterm infants with evolving or established bronchopulmonary dysplasia (BPD) is essential for the development of more effective preventive interventions.

Study design:  Thirty-two infants with a gestational age (GA) of <32 weeks who died of BPD or had BPD but died due to other causes were included in the study. The associations of clinical data with histopathological changes in the lungs were assessed.

Results:  The mean (standard deviation) GA of infants was 26.7 (1.9) weeks, and the mean birth weight was 919.7 (242.9) g. We revealed significant associations of maternal smoking with vascular hypertension lesions (r _s = 0.5, p < 0.05) in infants' lungs. Intrauterine growth retardation increased the risk of extensive fibroproliferation (r _s = 0.4, p < 0.05). In infants with patent ductus arteriosus (PDA) requiring treatment, muscle hyperplasia (r _s = 0.5, p < 0.05) was detected more often. The longer duration of mechanical ventilation (MV) correlated with diffuse interstitial fibroproliferation (r _s = 0.5, p < 0.05), airway epithelial lesions (r _s = 0.3, p < 0.05), and airway muscle hyperplasia (r _s = 0.4, p < 0.05). In infants who needed the longer MV and/or oxygen supplementation, an increased incidence of extensive fibroproliferation was found (r _s = 0.4 and r _s = 0.4 respectively, p < 0.05). Antenatal steroids decreased the incidence of diffuse interstitial fibrosis (r _s = - 0.4, p < 0.05).

Conclusion:  In very preterm infants with a GA of less than 32 weeks, lack of antenatal steroid prophylaxis, intrauterine growth restriction, presence of hemodynamically significant PDA, and prolonged MV or oxygen supplementation are associated with the pathomorphological lung changes that are more typical for "old" BPD. Traditional preventive measures against BPD remain essential in a modern population of very preterm infants.

Key points: · Pathomorphological lung changes correlate with clinical data in very preterm infants who died of BPD.. · Lack of antenatal steroids prophylaxis, growth retardation, PDA, and prolonged mechanical ventilation affect lungs.. · Traditional BPD preventive measures remain essential in the modern population of preterm infants..