Increased nitrosothiols in exhaled breath condensate in inflammatory airway diseases

Am J Respir Crit Care Med. 2001 Mar;163(4):854-8. doi: 10.1164/ajrccm.163.4.2001108.


Nitrosothiols (RS-NOs) are formed by interaction of nitric oxide (NO) with glutathione and may limit the detrimental effect of NO. Because NO generation is increased in airway inflammation, we have measured RS-NOs in exhaled breath condensate in patients with asthma, cystic fibrosis, or chronic obstructive pulmonary disease (COPD). We also measured exhaled NO and nitrite (NO(2-)) in the same subjects. RS-NOs were detectable in exhaled breath condensate of all subjects. RS-NOs were higher in subjects with severe asthma (0.81 +/- 0.06 microM) when compared with normal control subjects (0.11 +/- 0.02 microM, p < 0.01) and with subjects with mild asthma (0.08 +/- 0.01 microM, p < 0.01). Elevated RS-NOs values were also found in patients with cystic fibrosis (0.35 +/- 0.07 microM, p < 0.01), in those with COPD (0.24 +/- 0.04 microM, p < 0.01) and in smokers (0.46 +/- 0.09 microM, p < 0.01). In current smokers there was a correlation (r = 0.8, p < 0.05) between RS-NOs values and smoking history (pack/year). We also found elevated concentrations of NO(2-) in patients with severe asthma, cystic fibrosis, or COPD, but not in smokers or patients with mild asthma. This suggests that exhaled NO(2-) is less sensitive than exhaled RS-NOs. This study has shown that RS-NOs are detectable in exhaled breath condensate of healthy subjects and are increased in patients with inflammatory airway diseases. As RS-NOs concentrations in exhaled breath condensate vary in the different airway diseases and increase with the severity of asthma, their measurement may have clinical relevance as a noninvasive biomarker of nitrosative stress.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Asthma / physiopathology*
  • Biomarkers / analysis
  • Breath Tests
  • Cystic Fibrosis / physiopathology*
  • Female
  • Humans
  • Inflammation / physiopathology
  • Lung Diseases, Obstructive / physiopathology*
  • Male
  • Mercaptoethanol*
  • Middle Aged
  • Nitric Oxide / metabolism
  • Nitroso Compounds / analysis
  • Nitroso Compounds / metabolism*
  • Probability
  • Prognosis
  • Reference Values
  • Respiratory Function Tests
  • S-Nitrosothiols*
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Smoking / physiopathology*
  • Statistics, Nonparametric


  • Biomarkers
  • Nitroso Compounds
  • S-Nitrosothiols
  • Nitric Oxide
  • Mercaptoethanol
  • S-nitrosomercaptoethanol