title: Elevated exhalation of hydrogen peroxide in patients with systemic sclerosis.
abstract: BACKGROUND
  Systemic sclerosis is accompanied by an influx of activated phagocytes into distal airways. These cells release H2O2, which may evaporate from the airways surface and be detected in expired breath condensate. We tested whether patients with systemic sclerosis exhale more H2O2 than healthy subjects and whether breath condensate H2O2 levels correlate with some clinical parameters.
  
  
  METHODS
  H2O2 was measured fluorimetrically in the expired breath condensate of 27 patients (22 women, five men, mean age 49 +/- 13.1 years) with systemic sclerosis and 27 age- and sex- matched healthy controls.
  
  
  RESULTS
  Exhaled H2O2 levels were 3.5-fold higher (0.88 +/- 0.62 microM vs. 0.25 +/- 0.17 microM, P < 0.001) in the patients with systemic sclerosis than in the controls. Treatment with cyclophosphamide and/or prednisone (29 +/- 50 months, range 3-168 months) did not significantly decrease H2O2 exhalation (0.78 +/- 0.50 microM, n= 10 vs. 0.94 +/- 0.67 microM, n= 17, P > 0.05). No significant difference was found between patients with limited and diffuse scleroderma (1.03 +/- 0.69 microM, n= 17 vs. 0.63 +/- 0.41 microM, n= 10, P > 0.05). H2O2 levels correlated with disease duration (r = 0.38, P < 0.05) and time from the first Raynaud's episode (r = 0.44, P < 0.05).
  
  
  CONCLUSIONS
  Patients with systemic sclerosis exhale more H2O2 than healthy controls, suggesting involvement of reactive oxygen species in disease processes. Lack of significant intergroups differences in H2O2 levels may have resulted from the small number of patients analyzed.
authors.affiliation: Department of Experimental and Clinical Physiology, Institute of Physiology and Biochemistry, Medical University of Lodz, Lodz, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Łuczyñska
authors.forename: U
authors.initials: U
authors.lastname: Szkudlarek
authors.forename: B
authors.initials: B
authors.lastname: Dziankowska-Bartkowiak
authors.forename: E
authors.initials: E
authors.lastname: Waszczykowska
authors.forename: M
authors.initials: M
authors.lastname: Kasielski
authors.forename: A
authors.initials: A
authors.lastname: Sysa-Jedrzejowska
authors.forename: D
authors.initials: D
authors.lastname: Nowak
mesh_terms: D001944:Breath Tests / Q000379:methods; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D017382:Reactive Oxygen Species / Q000378:metabolism; D012595:Scleroderma, Systemic / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide