title: Nitrosative stress, heme oxygenase-1 expression and airway inflammation during severe exacerbations of COPD.
abstract: OBJECTIVE
  The aim of this study was to examine the relationship between airway inflammation, nitrosative stress, heme-oxygenase expression, and acute severe exacerbations of COPD.
  
  
  METHODS
  We measured heme oxygenase (HO)-1, inducible nitric oxide (NO) synthase expression and nitrotyrosine formation, as well as eosinophilic cationic protein, myeloperoxidase (MPO), interleukin (IL-8), and granulocyte macrophage-colony stimulating factor levels in induced sputum samples from 12 COPD patients (mean +/- SD; FEV1 40 +/- 14% predicted) at the onset of an acute severe exacerbation of COPD requiring hospital admission and 16 weeks after remission.
  
  
  RESULTS
  We demonstrated increased percentages (p = 0.001) and absolute numbers (p = 0.028) of total nitrotyrosine positive (+ve) inflammatory cells (ie, polymorphonuclear cells and macrophages), increased percentages (p = 0.04) and absolute numbers (p = 0.05) of total HO-1 +ve inflammatory cells, and increased MPO (p = 0.005) and IL-8 levels (p = 0.028) during severe exacerbation compared with the stable state.
  
  
  CONCLUSIONS
  Our results support the hypothesis of an involvement of inflammatory and nitrosative stress in severe COPD exacerbations. Future therapeutic strategies may aim at regulating inflammation and NO synthesis during COPD exacerbations.
authors.affiliation: Department of Thoracic Medicine, University of Crete, Medical School, PO Box 1352, 71110 Heraklion, Crete, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Tsoumakidou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Tzanakis
authors.forename: Georgios
authors.initials: G
authors.lastname: Chrysofakis
authors.forename: Nikolaos M
authors.initials: NM
authors.lastname: Siafakas
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001991:Bronchitis / Q000503:physiopathology; D015331:Cohort Studies; D018450:Disease Progression; D047150:Eosinophil Cationic Protein / Q000032:analysis / Q000378:metabolism*; D005260:Female; D006419:Heme Oxygenase (Decyclizing) / Q000032:analysis / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*; D009195:Peroxidase / Q000032:analysis / Q000378:metabolism*; D011336:Probability; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000201:enzymology*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013183:Sputum; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D008565:Membrane Proteins; D009195:Peroxidase; D019001:Nitric Oxide Synthase; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D047150:Eosinophil Cationic Protein