Pulmonary surfactant dysfunction in pediatric cystic fibrosis: Mechanisms and reversal with a lipid-sequestering drug

Background: Airway surfactant is impaired in cystic fibrosis (CF) and associated with declines in pulmonary function. We hypothesized that surfactant dysfunction in CF is due to an excess of cholesterol with an interaction with oxidation. Methods: Surfactant was extracted from bronchial lavage fluid from children with CF and surface tension, and lipid content, inflammatory cells and microbial flora were determined. Dysfunctional surfactant samples were re-tested with a lipid-sequesteringagent, methyl-beta-cyclodextrin (M beta CD). Results: CF surfactant samples were unable to sustain a normal low surface tension. M beta CD restored surfactant function in a majority of samples.Mechanistic studies showed that the dysfunction was due to a combination of elevated cholesterol and an interaction with oxidized phospholipids and their pro-inflammatory hydrolysis products. Conclusion: We confirm that CF patients have impaired airway surfactant function which could be restored with m beta cD. These findings have implications for improving lung function and mitigating inflammation in patients with CF. (C) 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.