Update on pathogenesis of cystic fibrosis lung disease

Purpose of review It has been an ongoing challenge to translate knowledge pertaining to the molecular basis of cystic fibrosis (CF) into a clear understanding of the development of CF lung disease. Various hypotheses have attempted to explain the apparent breach of innate defenses in CF, although a definitive explanation has been elusive. Recent findings Recent data suggest that altered ion transport functions-namely sodium hyperabsorption and reduced chloride secretion-lead to a depletion of airway surface liquid. As a result, the overlying mucus layer may encroach upon cell surfaces and become adherent, thus interfering with cilia-dependent and cough clearance. These static, and ultimately anaerobic, niches provide a favorable environment for the development of bacterial biofilms and persistent infection with Pseudomonas aeruginosa. Summary With a better understanding of pathogenic steps leading to CF lung disease, we may now be able to direct the development of therapies that will substantially improve disease outcomes.