title: Short- and long-term antibiotic treatment reduces airway and systemic inflammation in non-cystic fibrosis bronchiectasis.
abstract: BACKGROUND
  The vicious cycle hypothesis of bronchiectasis argues that bacterial colonization leads to airway inflammation and progressive lung damage. The logical extension of this hypothesis is that acute or chronic antibiotic therapy should improve airway inflammation and clinical outcome. There are little data to support this hypothesis in patients with non-cystic fibrosis (CF) bronchiectasis.
  
  
  OBJECTIVE
  To determine whether acute or chronic antibiotic therapy improves airway inflammation and clinical outcome in non-CF bronchiectasis.
  
  
  METHODS
  The relationship between bacterial load and airway and systemic inflammation was investigated in 385 stable patients, 15 stable patients treated with intravenous antibiotics, and 34 patients with an exacerbation of bronchiectasis treated with intravenous antibiotics. Long-term antibiotic therapy was investigated using samples from a 12-month controlled trial of nebulized gentamicin.
  
  
  RESULTS
  In stable patients, there was a direct relationship between airway bacterial load and markers of airway inflammation (P < 0.0001 for all analyses). High bacterial loads were associated with higher serum intercellular adhesion molecule-1, E-selectin, and vascular cell adhesion molecule-1 (P < 0.05 above bacterial load ≥1 × 10(7) cfu/ml). In stable patients, there was a direct relationship between bacterial load and the risk of subsequent exacerbations (odds ratio, 1.20; 95% confidence interval, 1.11-1.29; P < 0.0001) and severe exacerbations (odds ratio, 1.11; 95% confidence interval, 1.01-1.21; P = 0.02). Short- and long-term antibiotic treatments were associated with reductions in bacterial load, airways, and systemic inflammation.
  
  
  CONCLUSIONS
  High airway bacterial loads in non-CF bronchiectasis are associated with airway and systemic inflammation and a greater risk of exacerbations. Short- and long-term antibiotic therapy reduce markers of airways and systemic inflammation.
authors: Royal Infirmary of Edinburgh, Department of Respiratory Medicine, Edinburgh, United Kingdom. jamesdchalmers@googlemail.com
authors: James D
authors: JD
authors: Chalmers
authors: Maeve P
authors: MP
authors: Smith
authors: Brian J
authors: BJ
authors: McHugh
authors: Cathy
authors: C
authors: Doherty
authors: John R
authors: JR
authors: Govan
authors: Adam T
authors: AT
authors: Hill
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D058491:Bacterial Load; D015415:Biomarkers / Q000378:metabolism; D001987:Bronchiectasis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D015331:Cohort Studies; D004334:Drug Administration Schedule; D005260:Female; D006304:Health Status; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; D015815:Cell Adhesion Molecules; D018836:Inflammation Mediators