Circulating immunoreactive interleukin-6 in cystic fibrosis

Am J Respir Crit Care Med. 1998 Jun;157(6 Pt 1):1764-9. doi: 10.1164/ajrccm.157.6.9704086.


We measured circulating and sputum-sol concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), neutrophil elastase-alpha1-antiproteinase complex (NEAPC), and C-reactive protein (CRP) in an exacerbation, after antibiotic treatment, and in clinically stable patients with cystic fibrosis and chronic pulmonary infection with Pseudomonas aeruginosa. The aim was to determine the compartmental patterns of a proinflammatory and anti-inflammatory cytokine compared with other markers of inflammatory activity in cystic fibrosis. IL-6, NEAPC, CRP, and absolute neutrophil count were reduced after antibiotic treatment, p < 0.01. IL-6 and CRP concentrations were greater, p = 0.007, and p = 0.01, respectively, in a stable group of patients compared with those at the end of an exacerbation. IL-6 and CRP concentrations were related (r = 0.836, p < 0.0001), and both were greater than in matched control subjects (p < 0.001) at all times studied. Sputum-sol concentrations of IL-6 after treatment were positively related to FEV1 and FVC and inversely related to concentrations of neutrophil elastase. The separation between patients and healthy subjects, and the reduction of IL-6 after antibiotic treatment indicates it could be used as a marker of inflammation, but its relationship to other markers depends on the compartment in which it is measured.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • C-Reactive Protein / analysis
  • Chronic Disease
  • Cystic Fibrosis / blood*
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / physiopathology
  • Forced Expiratory Volume
  • Humans
  • Interleukin-6 / analysis
  • Interleukin-6 / blood*
  • Interleukin-6 / immunology
  • Leukocyte Elastase / analysis
  • Proteins / analysis
  • Pseudomonas Infections / complications
  • Pseudomonas Infections / drug therapy
  • Respiratory Tract Infections / complications
  • Respiratory Tract Infections / drug therapy
  • Sputum / chemistry
  • Tumor Necrosis Factor-alpha / analysis
  • Vital Capacity
  • alpha 1-Antitrypsin / analysis


  • Interleukin-6
  • Proteins
  • Tumor Necrosis Factor-alpha
  • alpha 1-Antitrypsin
  • alpha 1-antitrypsin-leukocyte elastase complex
  • C-Reactive Protein
  • Leukocyte Elastase