Late Breaking Abstract - Elevated airway lymphocytes in adults born prematurely with a history of bronchopulmonary dysplasia

Abstract

Background: Preterm birth is a risk factor for lung disease later in life. Bronchopulmonary dysplasia (BPD) is a common cause of respiratory insufficiency in children born preterm. The mechanisms underlying development of chronic airway disease due to premature birth is unknown. Aim: To characterize cellular profiles in the large airways in adults born preterm with and without BPD. Methods: Adults (age 18-23 years) born preterm ( 37 weeks) and mild allergic asthmatics (n=22, >37 weeks) from the LUNAPRE (LUNg Adult PREmature; www.clinicaltrials.gov/ct/show/NCT02923648) cohort were studied. Bronchial wash (BW) was retrieved during bronchoscopy by instilling 2 x 10 mL phosphate-buffered saline in two different segments in the right upper lobe which immediately was recovered by gently suction. Cells in BW were scored on cytospin slides stained with May Grunwald Giemsa. Results: Neither total cell count nor the major cell type in BW, epithelial (mean 51.3%), differed between the groups. Preterm born individuals with and without BPD had higher proportions of lymphocytes compared with healthy controls (p=0.003 and p=0.024 respectively). Lymphocytes in BW was negatively correlated with post-bronchodilator forced vital capacity (FVC% of predicted) in the pooled preterm subjects (p=0.045). Conclusions: Our results may suggest mechanisms involving adaptive immune responses in the development of airway disease in adults born preterm, in particular in those with a history of BPD. Further characterization of lymphocyte subtypes and correlations to clinical parameters are warranted.