Complement Effectors of Inflammation in Cystic Fibrosis Lung Fluid Correlate with Clinical Measures of Disease

PLoS One. 2015 Dec 7;10(12):e0144723. doi: 10.1371/journal.pone.0144723. eCollection 2015.


In cystic fibrosis (CF), lung damage is mediated by a cycle of obstruction, infection, and inflammation. Here we explored complement inflammatory effectors in CF lung fluid. In this study soluble fractions (sols) from sputum samples of 15 CF patients were assayed for complement effectors and analyzed with clinical measurements. The pro-inflammatory peptide C5a was increased 4.8-fold (P = 0.04) in CF sols compared with controls. Incubation of CF sols with P. aeruginosa or S. aureus increased C5a concentration 2.3-fold (P = 0.02). A peptide inhibitor of complement C1 (PIC1) completely blocked the increase in C5a concentration from P. aeruginosa in CF sol in vitro (P = 0.001). C5a concentration in CF sol correlated inversely with body mass index (BMI) percentile in children (r = -0.77, P = 0.04). C3a, which has anti-inflammatory effects, correlated positively with FEV1% predicted (rs = 0.63, P = 0.02). These results suggest that complement effectors may significantly impact inflammation in CF lung fluid.

Publication types

  • Comparative Study

MeSH terms

  • Body Fluids / immunology*
  • Case-Control Studies
  • Child
  • Complement C5a / metabolism*
  • Cystic Fibrosis / immunology*
  • Cystic Fibrosis / physiopathology
  • Follow-Up Studies
  • Humans
  • Inflammation / immunology*
  • Inflammation / physiopathology
  • Lung / immunology*
  • Lung / physiopathology
  • Prognosis
  • Pseudomonas Infections / immunology*
  • Pseudomonas Infections / microbiology
  • Pseudomonas Infections / physiopathology
  • Sputum / immunology*
  • Staphylococcus aureus / immunology


  • Complement C5a

Grant support

The authors have no support or funding to report.