Pulmonary surfactant, lung function, and endobronchial inflammation in cystic fibrosis

Am J Respir Crit Care Med. 2004 Nov 1;170(9):1000-5. doi: 10.1164/rccm.200405-575OC. Epub 2004 Jul 21.


Cystic fibrosis (CF) lung disease is primarily a disease of the small airways. We hypothesized that even in patients with normal lung function, a reduced surfactant function would be present and favor small airway obstruction. Bronchoalveolar lavages from 76 patients with CF (5-31 years, median 11) with well-conserved lung function (FEV1 94% predicted, range 78-121) and from 10 healthy control subjects were investigated. The deviation of the biophysical surfactant performance from normal, assessed in a bubble surfactometer, was small; however, the ability of the surfactant to maintain the patency of a narrow airway (% open) was significantly reduced. Surfactant protein (SP)-C level was increased, SP-B and SP-D were unchanged, whereas SP-A was decreased. Among the patients with CF, neutrophilic inflammation was modestly related to a poorer surfactant activity, but not to lung function. SP-D was reduced in proportion to the degree of inflammation and in the presence of bacteria. These findings in a large cohort of patients with CF with normal lung function show that the endobronchial airway inflammation is linked to early perturbations of the biophysical properties and immunologic components of pulmonary surfactant and opens fields for novel therapeutic interventions.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Biomarkers / analysis
  • Bronchoalveolar Lavage Fluid / chemistry*
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Cohort Studies
  • Cystic Fibrosis / diagnosis
  • Cystic Fibrosis / metabolism*
  • Female
  • Humans
  • Inflammation Mediators / analysis
  • Male
  • Pneumonia / microbiology
  • Pneumonia / physiopathology*
  • Probability
  • Prognosis
  • Pulmonary Surfactant-Associated Proteins / analysis
  • Pulmonary Surfactant-Associated Proteins / metabolism*
  • Respiratory Function Tests
  • Risk Assessment
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Statistics, Nonparametric


  • Biomarkers
  • Inflammation Mediators
  • Pulmonary Surfactant-Associated Proteins