LSC - 2024 - Delayed airway epithelial repair is correlated with airway obstruction in young adults born very preterm.

<bold>Introduction:</bold> A weakened epithelial barrier creates vulnerability to infection and injury, posing a risk to overall lung health. A repair defect has been identified in the airway epithelium of infants born preterm (Hillas et al., 2021). However, it is not known if this defect is intrinsic or transitory in nature. This study hypothesised that defective repair is evident in the airway epithelium of young adults born preterm and is associated with reduced lung function. <bold>Methods:</bold> Nasal brushings were collected from 6 term (20.9±0.7 years) and 29 preterm (<32 weeks gestation; 19.6±1.5 years) participants. Lung function was measured via spirometry at the time of brushing. Monolayer epithelial cultures were successfully established for 4 term and 15 preterm participants. Confluent cultures were scratch-wounded (WoundMaker®, Essen Bioscience) and repair tracked over 72 hours (IncuCyte ZOOM®, Essen Bioscience). <bold>Results:</bold> Mean FEV1/FVC was lower in preterm cultures failing to expand (−1.53±1.15 vs -1.00±0.99). Epithelial cells from term participants repaired within 72 hours (99±2% wound confluence). In contrast, preterm cells displayed reduced repair (71±28%, p<0.01) and closure rates varied (28-100%). Wound closure was positively correlated to both the FEV1 z-score (r=0.630; p<0.01) and the FEV1/FVC z-score (r=0.500; p<0.05). Past hospitalisations were also associated with worse repair (r=-0.677; p<0.05). <bold>Conclusion:</bold> Defective wound repair is present in the airway epithelium of adults born preterm. Reduced lung function is associated with a more pronounced repair defect, suggesting that impaired barrier integrity may play a role in preterm lung disease.