Airway ion transport impacts on disease presentation and severity in cystic fibrosis

Objectives: Abnormal airway ion transport is a feature of cystic fibrosis. The aim of this study was to investigate whether distinct components of ion transport are associated with the clinical expression and severity of the disease. Design and methods: Univariate and multivariate analyses were used to study interaction effects between nasal potential difference parameters and clinical status, recorded at stable conditions, in 75 F508del homozygous young adults. Results: All patients demonstrated increased sodium and reduced chloride conductances. Less sodium transport abnormalities were related to better respiratory function and nutrition. Presentation with digestive symptoms at diagnosis was associated with lower chloride conductance. With an accuracy of 85% good nutritional status was linked to more preserved lung function, increasing age and more preserved chloride conductance. Conclusions: Ion transport abnormalities have distinct clinical outcomes. Sodium conductance relates to respiratory function and nutrition; chloride conductance to nutrition and presentation with digestive symptoms at diagnosis. (C) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.