title: Comparison of Airway and Systemic Malondialdehyde Levels for Assessment of Oxidative Stress in Cystic Fibrosis.
abstract: BACKGROUND
  Oxidative stress plays a pivotal role in the pathogenesis of cystic fibrosis (CF). In this study, airway and systemic oxidative stress was investigated in CF using malondialdehyde (MDA), an established by-product of polyunsaturated fatty acid peroxidation.
  
  
  METHODS
  Exhaled breath condensate (EBC), sputum, and plasma were collected from 40 stable CF patients during routine clinical visits and from 25 healthy controls. MDA was measured by high-performance liquid chromatography.
  
  
  RESULTS
  MDA levels in sputum (279.8 ± 14.7 vs. 92.7 ± 9.2 nmol/L, p < 0.0001), EBC (139.9 ± 6.7 vs. 71.5 ± 4.3 nmol/L, p < 0.0001), and plasma (176.1 ± 15.9 vs. 129.6 ± 12.9 nmol/L, p < 0.05) were increased in patients with CF compared to healthy controls. MDA measurement in sputum [area under receiver operating characteristic curve (AUC): 0.977, p < 0.0001] or EBC (AUC: 0.94, p < 0.0001) discriminated between patients and controls with greater accuracy than in plasma (AUC: 0.677, p < 0.05). Sputum and EBC MDA levels were elevated in patients with severe pulmonary dysfunction [forced expiratory volume in 1 s (FEV1) <50 % predicted] compared to those with mild-to-moderate functional impairment (FEV1 ≥50 % predicted) (p < 0.05). MDA concentrations in CF patients colonized either with Pseudomonas aeruginosa or with other bacteria were similar (p = NS). The intra- and inter-assay repeatabilities of MDA measurements was similar in all the three types of samples, while the between-visit variability was higher in plasma.
  
  
  CONCLUSIONS
  MDA is a potential new airway marker of oxidative stress in patients with CF. Sputum MDA differentiates best between patients and healthy subjects.
authors.affiliation: Department of Pathophysiology, National Koranyi Institute of TB and Pulmonology, Piheno ut 1, Budapest, 1121, Hungary, antusb@hotmail.com.
authors.forename: Balazs
authors.initials: B
authors.lastname: Antus
authors.forename: Orsolya
authors.initials: O
authors.lastname: Drozdovszky
authors.forename: Imre
authors.initials: I
authors.lastname: Barta
authors.forename: Krisztina
authors.initials: K
authors.lastname: Kelemen
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001944:Breath Tests; D016022:Case-Control Studies; D003550:Cystic Fibrosis / Q000097:blood* / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000032:analysis / Q000097:blood*; D009504:Neutrophils; D009569:Nitric Oxide / Q000032:analysis; D018384:Oxidative Stress; D011552:Pseudomonas Infections / Q000097:blood; D011550:Pseudomonas aeruginosa; D012372:ROC Curve; D015203:Reproducibility of Results; D013183:Sputum / Q000737:chemistry* / Q000166:cytology; D055815:Young Adult
chemical_list: D009569:Nitric Oxide; D008315:Malondialdehyde