Abstract
Cystic fibrosis can manifest in many organs, but infection and inflammation of the airways cause the most severe morbidity and mortality. Early studies suggested that increased epithelial Na(+) reabsorption may be a key initiating event in cystic fibrosis lung disease. However, the importance of Na(+) hyperabsorption and the consequent depletion of pericellular airway liquid in cystic fibrosis lung disease has been called into question by a recent study by Jeng-Haur Chen et al.. Newborn pigs lacking cystic fibrosis transmembrane conductance regulator (CFTR(−/−) pigs) developed lung pathology reminiscent of human cystic fibrosis. Although epithelia from these pigs had reduced Cl(−) and HCO(3)(−) transport, there were no alterations in Na(+) or liquid absorption, suggesting that defective anion transport is responsible for cystic fibrosis lung disease. Here three experts comment on how these findings might affect our understanding of cystic fibrosis lung pathogenesis and strategies for cystic fibrosis therapy.