Symptoms of bronchial asthma are a manifestation of airway inflammation. Circulatory leucocytes (predominantly eosinophils, mast cells and neutrophils), release inflammatory mediators, including reactive oxygen species, i.e. superoxide anion which is dismutated to hydrogen peroxide (H 2 O 2 ). Neutrophils from asthmatics generate greater amounts of these species than those of healthy subjects. Some of the H 2 O 2 and thiobarbituric acid-reactive products (TBARs) can evaporate from alveolar lining fluid, and could be expired from the airways of asthmatics. In this study, therefore, we determined whether asthmatic patients exhale more H 2 O 2 and TBARs than healthy subjects.We examined 10 healthy subjects as a control group and 21 asthmatic subjects. In asthmatic subjects, forced expiratory volume in one second (FEV1), was 68±9% of predicted value, peak expiratory flow rate (PEFR) was 65±8% pred, and bronchial reversibility was 34±5% of prebronchodilated FEV1. The mean H 2 O 2 level measured spectrofluorimetrically in the expired breath condensate of asthmatic subjects was 26 fold higher than that in healthy controls (0.26±0.29 vs 0.01±0.03 nM; p<0.05). The concentration of TBARs in breath condensate was also higher in asthmatic patients compared with nonasthmatics (0.073±0.071 vs 0.004±0.009 nM; p<0.05). There was a significant correlation between H 2 O 2 level and concentration of TBARs in asthmatic patients (r=0.74; p<0.01). There was also a strong inverse correlation between H 2 O 2 content of all asthmatics and FEV1% pred (r= -0.63; p<0.005) and PEFR% pred (r= -0.52; p<0.05).We conclude that there are elevated levels of hydrogen peroxide and thiobarbituric acid-reactive products in expired breath condensate of asthmatic patients, and that measurement of these substances in the expired breath condensate could be a simple, noninvasive method that could be used as a biochemical marker of airway inflammation. Eur Respir J 1997; 10: 1235-1241

IntroductionEicosanoids and oxidants play an important role in inflammation, but their role in chronic obstructive pulmonary disease (COPD) is uncertain. In this study we hypothesized that levels of exhaled leukotrienes, prostaglandins and biomarkers of oxidative stress are increased in infectious exacerbations of COPD and that they decrease after antibiotic therapy.Material and methodsCysteinyl-leukotrienes (LTs), leukotriene B4 (LTB4), prostaglandin E4, hydrogen peroxide (H2O2) and 8-isoprostane were measured in exhaled breath condensate (EBC) in 16 COPD patients with infectious exacerbations (mean age 64 ±12 years, 13 male) on day 1, during antibiotic therapy (days 2-4), 2-4 days after therapy and at a follow-up visit when stable (21-28 days after therapy).ResultsThere was a significant fall in concentration of cys-LTs, LTB4 and 8-isoprostane at visit 3 compared to day 1 (cys-LTs: 196.5 ±38.4 pg/ml vs. 50.1 ±8.2 pg/ml, p < 0.002; LTB4: 153.6 ±25.5 pg/ml vs. 71.9 ±11.3 pg/ml, p < 0.05; 8-isoprostane: 121.4 ±14.6 pg/ml vs. 56.1 ±5.2 pg/ml, p < 0.03, respectively). Exhaled H2O2 was higher on day 1 compared to that at visits 2 and 3 (0.74 ±0.046 µM vs. 0.52 ±0.028 µM and 0.35 ±0.029 µM, p < 0.01 and p < 0.01, respectively). Exhaled PGE2 levels did not change during exacerbations of COPD. Exhaled eicosanoids and H2O2 in EBC measured at the follow-up visit (stable COPD) were significantly higher compared to those from healthy subjects.ConclusionsWe conclude that eicosanoids and oxidants are increased in infectious exacerbations of COPD. They are also elevated in the airways of stable COPD patients compared to healthy subjects.

H2O2 is elevated in the exhaled air condensate in several inflammatory disorders of the lung, including bronchial asthma, and thus may reflect inflammatory processes in the airways. Exhaled H2O2 may be used to guide the anti-inflammatory treatment of patients with asthma. Therefore in this study we analysed the effect of inhaled glucocorticosteroid beclomethasone for 4 weeks on H2O2 level in the exhaled air condensate. Seventeen asthmatics and 10 healthy subjects were included to the study. Eleven patients were given inhaled beclomethasone and six were given placebo (3M Health Care). In all patients pulmonary function tests were performed. H2O2 in the expired air condensate was measured spectrofluorimetically (homovanillic acid method). Inhaled beclomethasone significantly decreased H2O2 in the expired air condensate in the active-treatment group, with a fall from baseline on day 1 which remained on day 43 (follow-up) (P<0.05). Exhaled H2O2 in the active-treatment group was significantly lower than that in placebo group (P<0.05). A negative correlation between H2O2 and forced expiratory volume in 1 sec (FEV1) on day 29 was observed. The decrease in exhaled H2O2 in the active-treatment group was accompanied by an improvement in pulmonary function tests results. Inhaled glucocorticoids reduce the level of H2O2 in the expired air condensate of asthmatic patients over a 4-week period and this may reflect their anti-inflammatory activity in lung diseases.

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Background8-Isoprostane (8-IP) is a marker of lipid peroxidation. Elevated concentrations have been reported in BAL fluid and exhaled breath condensate (EBC) in sarcoidosis (S). To validate the prognostic value of this marker we tested whether: 1. high initial EBC 8-IP predispose to more severe disease; 2. low initial concentrations increase a chance of early remission; 3. remissions are connected with the decrease of EBC 8-IP.Methods40 patients (S) have been examined initially (V1) and after 8.5 ± 0.5 months (V2). EBC 8-IP concentrations were measured by ELISA. Chest X-ray, lung function test, serum ACE and Ca2+ concentrations, 24 hrs Ca2+loss, abdominal ultrasonography, symptoms evaluation were performed.ResultsWe confirmed higher concentrations of 8-IP in EBC of patients with sarcoidosis (p = 0.001). Relative risk (RR) of persistence of disease at V2 when initial 8-IP was above 20 pg/mL was 1.04, and the frequency distributions estimated by χ2 test were not significantly different. A chance (RR) of early complete remission when V1 8-IP was below DL, was 3.33 (p = 0.04 by χ2 test). A significant decrease of 8-IP at V2 was observed only in patients who received treatment (p = 0.03), but not in those with spontaneous remission.ConclusionsWe come to the conclusion, that low initial 8-IP may be a positive prognostic factor. A decrease of 8-IP in treated patients reflects a non-specific effect of treatment and is not related to mere regression of disease.