Leukotrienes and 8-isoprostane in exhaled breath condensate of children with stable and unstable asthma

BACKGROUND: Cysteinyl-leukotrienes (cys-LTs) and 8-isoprostane are biomarkers of airway inflammation and oxidative stress. OBJECTIVE: The aim of this study was to evaluate cys-LT and 8-isoprostane levels in exhaled breath condensate (EBC) of children with different degrees of asthma severity. METHODS: EBC was collected from 14 steroid-naive children with mild persistent asthma, 13 children with stable mild- to-moderate persistent asthma treated with inhaled corticosteroids (ICS), 9 ICS-treated children with unstable asthma, and 19 healthy children. RESULTS: In the three groups of asthmatic children, EBC concentrations of cys-LTs and 8-isoprostane were significantly higher than in control children (steroid-naive asthmatic children: cys-LTs median, 10.8 pg/mL, P <.001, 8-isoprostane, 16.2 pg/mL, P <.001; ICS-treated stable asthmatic children: cys-LTs, 12.7 pg/mL, P <.001, 8-isoprostane, 18.1 pg/mL, P <.001; children with unstable asthma: cys-LTs, 106.0 pg/mL, P <.01, 8-isoprostane, 29.7 pg/mL, P <.01; control children: cys-LTs, 4.3 pg/mL, 8-isoprostane, 3.5 pg/mL). Cys-LT levels were higher in children with unstable asthma than in the other two asthmatic groups (P <.05). FE(NO) levels were significantly higher in steroid-naive and in children with unstable asthma compared with ICS-treated children with stable asthma (P <.01). CONCLUSIONS: Our study shows that EBC cys-LTs and 8-isoprostane concentrations are higher in asthmatic children than in healthy control children, with scattered values in patients with unstable asthma. These findings suggest that EBC eicosanoid measurement may have useful clinical implications for investigating phenotype differences among asthmatic patients.     

Inflammatory markers and Acid-base equilibrium in exhaled breath condensate of stable and unstable asthma patients

Background: Nitrosative and acid stress play an important role in the pathogenesis of asthma. The aim of this study was to evaluate whether, in asthmatics, a link exists between the concentrations of nitrite/nitrate, ammonia and pH values in exhaled breath condensate (EBC) and asthma severity, lung function, exhaled nitric oxide (F(ENO)), total IgE, eosinophil cationic protein (ECP) and blood eosinophilia. Methods: The above-mentioned parameters were measured in 19 healthy volunteers and 91 allergic asthmatics divided into three groups, i.e. 22 subjects with steroid-na?ve stable asthma, 35 with inhaled corticosteroid (ICS)-treated stable asthma and 34 with ICS-treated unstable asthma. Results: Compared with healthy subjects, EBC from asthmatics had significantly lower pH values and ammonia concentrations and significantly higher levels of nitrite/nitrate. The extent of these changes was higher in patients with unstable than in patients with steroid-na?ve and stable ICS-treated asthma. The EBC pH was positively correlated with ammonia and negatively correlated with nitrite/nitrate, F(ENO) or blood eosinophilia in all three groups of asthmatics. Significant positive correlations between EBC nitrite/nitrate and blood eosinophilia, ECP levels or F(ENO) were observed in all groups of asthmatics. Significant negative correlations between EBC ammonia and nitrite/nitrate, F(ENO), ECP concentrations or blood eosinophilia were demonstrated in the groups of ICS-na?ve and ICS-treated stable asthmatics. Conclusions: In asthmatic patients there is a relationship between EBC pH, ammonia and nitrite/nitrate concentrations and other recognized markers of airway inflammation. EBC pH values, ammonia and nitrite/nitrate levels measured together may help to assess airway inflammatory status and asthma severity.     

Exhaled leukotrienes and prostaglandins in asthma

BACKGROUND: Most of the studies investigating the role of leukotrienes (LTs) and prostaglandins (PGs) in asthma have used invasive (eg, bronchoalveolar lavage fluid) or semi-invasive (eg, sputum induction) techniques. Others have measured eicosanoids in plasma or urine, probably reflecting systemic rather than lung inflammation. Collection of exhaled breath condensate (EBC) is a noninvasive method to collect airway secretions. OBJECTIVE: We sought to investigate whether eicosanoids are measurable in EBC, to show possible differences in their concentrations in asthmatic patients and healthy subjects, and to investigate whether exhaled eicosanoids correlate with exhaled nitric oxide (NO), a marker of airway inflammation. METHODS: Twelve healthy nonsmokers and 15 steroid-naive patients with mild asthma were studied. Subjects attended on one occasion for pulmonary function tests, collection of EBC, and exhaled NO measurements. Exhaled LTB(4)-like immunoreactivity, LTE(4)-like immunoreactivity, PGE(2)-like immunoreactivity, PGD(2)-methoxime, PGF(2)(alpha)-like immunoreactivity, and thromboxane B(2)-like immunoreactivity were measured by means of enzyme immunoassays. RESULTS: LTE(4)-like immunoreactivity and LTB(4)-like immunoreactivity were detectable in EBC in healthy subjects, and their levels in asthmatic patients were increased about 3-fold (P <.0001) and 2-fold (P <.0005), respectively. Exhaled NO was increased in asthmatic patients compared with healthy subjects (P <.0001). There was a correlation between exhaled LTB(4) and exhaled NO (r = 0.56, P <.04) in patients with asthma. When measurable, prostanoid levels were similar in asthmatic patients and control subjects. CONCLUSIONS: Exhaled LTE(4) and LTB(4) are increased in steroid-naive patients with mild asthma. EBC may be proved to be a novel method to monitor airway inflammation in asthma.     

3-Nitrotyrosine, a marker of nitrosative stress, is increased in breath condensate of allergic asthmatic children

BACKGROUND: Asthmatic patients have high exhaled nitric oxide (NO) levels. NO-mediated inflammatory actions are mainly due to NO conversion into reactive nitrogen species, which can lead to nitrotyrosine formation. The aim of this study was to assess 3-nitrotyrosine (3-NT) levels in exhaled breath condensate (EBC) of asthmatic and healthy children and to investigate whether there is any relationship with exhaled NO (FE(NO)) and lung function. METHODS: The study included 20 asthmatic children (10 steroid-naive with intermittent asthma, 10 steroid-treated with unstable persistent asthma) and 18 healthy controls. They underwent FE(NO) measurement, EBC collection and spirometry. 3-NT was measured by a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method in isotopic dilution. RESULTS: The median EBC concentration of 3-NT (expressed as nitrotyrosine/tyrosine ratio x 100) in asthmatic children was fivefold higher than in healthy subjects [0.23% (0.12-0.32) vs 0.04% (0.02-0.06), P < 0.001] with no difference between steroid-naive and unstable steroid-treated asthmatic patients. FE(NO) levels were higher in asthmatic [44.6 ppb (36.0-66.0)] than in healthy children [7.5 ppb (6.0-8.8), P < 0.001]. No correlation was found among 3-NT, FE(NO) and lung function parameters. CONCLUSION: Nitrotyrosine is high in EBC of asthmatic children and could be considered as a noninvasive marker of nitrosative events in the airways.     

Exhaled air temperature in asthma: methods and relationship with markers of disease

BACKGROUND: Exhaled breath temperature has been proposed as a surrogate marker for the evaluation of airway inflammation in asthmatic patients. OBJECTIVE: The aim of the present study was to extend the investigation of exhaled air temperature as a means for the evaluation of airway inflammation using a professionally developed instrument. METHODS: Fifty-seven children, 41 allergic mild asthmatics and 16 healthy controls have been evaluated. They underwent exhaled air temperature and lung function measurement. The asthmatic children also underwent exhaled nitric oxide measurement, and hypertonic saline sputum induction for the evaluation of eosinophil (EOS) percentage. RESULTS: The level of exhaled temperature was significantly higher in asthmatics than in controls, being 30.18+/-0.14 degrees C vs. 27.47+/-0.24 degrees C (P<0.001). In asthmatic children, a positive relationship was observed between exhaled air temperature and both exhaled nitric oxide (r=0.39; P=0.01) and EOS percentage in samples from induced sputum (rho=0.53; P=0.04). CONCLUSION: The data from the present study support the hypotheses that exhaled breath temperature is related to the degree of airway inflammation in asthma.     

Analysis of growth factors and inflammatory cytokines in exhaled breath condensate from asthmatic children

BACKGROUND: Vascular endothelial growth factor (VEGF), AA isoform of platelet-derived growth factor (PDGF-AA), and epidermal growth factor (EGF) are involved in the pathogenesis of airway inflammation in asthma. These molecules are closely associated with cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-4. This study investigates the relation between childhood asthma and levels of these mediators in exhaled breath condensate (EBC). METHODS: EBC was collected from asthmatic children and controls using a disposable collection kit, and the concentrations of VEGF, PDGF-AA, EGF, TNF-alpha and IL-4 in EBC were measured using sandwich enzyme immunoassays. Exhaled nitric oxide concentration was measured by a chemiluminescence analyzer. RESULTS: Thirty-five asthmatic patients aged between 7 and 18 years and 11 controls were recruited. Sixteen patients had intermittent asthma (IA) whereas 19 of them suffered from persistent asthma (PA). A significant correlation was found between IL-4 and TNF-alpha in EBC (rho = 0.374, p = 0.010). PDGF-AA levels in EBC were higher in subjects with diminished FEV1 (p = 0.023) whereas IL-4 concentrations were increased in asthmatics (p = 0.007) as well as subjects with increased plasma total IgE (p = 0.033). Patients with PA receiving high-dose inhaled corticosteroid (ICS) had higher EBC IL-4 concentration than those on low-dose ICS (p = 0.007). Linear regression revealed that PDGF-AA levels in EBC were negatively associated with FEV1 percentage (beta = -0.459, p = 0.006) among the asthmatic patients. CONCLUSIONS: IL-4 in EBC is increased in childhood asthma, and growth factors are detectable in a significant proportion of these children. Increased PDGF-AA is found in asthmatics with more severe airflow limitation.     

Exhaled breath condensate cysteinyl leukotrienes are increased in children with exercise-induced bronchoconstriction

BACKGROUND: It is recognized that airway inflammation has a central role in the pathogenesis of asthma, but how it relates to exercise-induced bronchoconstriction (EIB) is not completely understood. OBJECTIVE: The aim of our study was to investigate the relationship between EIB and baseline concentrations of cysteinyl leukotrienes (Cys-LTs) and other inflammatory markers in exhaled breath condensate (EBC). METHODS: EBC was collected, and the fraction of exhaled nitric oxide (FE NO ) was measured in a group of 19 asthmatic children, after which they performed a treadmill exercise test. Fourteen healthy children were enrolled as control subjects. RESULTS: The asthmatic children were divided into the EIB group (decrease in FEV 1 , > or =12%) and the non-EIB group. The EBC was analyzed for the presence of Cys-LTs, leukotriene B 4 , and ammonia. Asthmatic patients with EIB (mean FEV 1 decrease, 23% +/- 3%) had higher Cys-LT concentrations than either asthmatic patients without EIB or control subjects (42.2 pg/mL [median] vs 11.7 pg/mL and 5.8 pg/mL; P < .05 and P < .001, respectively). Ammonia concentrations were lower in both the EIB and non-EIB groups than in control subjects (253.2 microM and 334.6 microM vs 798.4 microM; P < .01 and P < .05, respectively). No difference in EBC leukotriene B 4 levels was found among the 3 groups. Both asthmatic groups had higher FE NO levels than control subjects ( P < .001). EBC Cys-LT ( P < .01; r = 0.7) and FE NO ( P < .05; r = 0.5) values both correlated significantly with the postexercise FEV 1 decrease. CONCLUSION: this study shows that EBC Cys-LT values are higher in asthmatic children with EIB and correlate with the decrease in FEV 1 after exercise. These findings suggest that the pathways of both Cys-LT and nitric oxide are involved in the pathogenesis of EIB.     

Noninvasive evaluation of airway inflammation in asthmatic patients who smoke: implications for application in clinical practice

BACKGROUND: Despite the limited pathological data in asthmatic patients who smoke, it is thought that cigarette smoking may modify airway inflammation. OBJECTIVES: To summarize the major clinical studies that have used samples obtained by noninvasive techniques, such as blood, urine, exhaled breath condensate (EBC), fractional exhaled nitric oxide (FeNO), and induced sputum, for the evaluation of airway inflammation and the response to treatment in asthmatic patients who smoke and to evaluate which biomarkers have been adequately validated to be used in routine clinical practice. DATA SOURCES: In this review, we collected the available literature that addressed this topic. We searched the MEDLINE database using a combination of the following keywords: smoking or asthma or inflammation or mechanisms or exhaled nitric oxide or induced sputum or EBC. STUDY SELECTION: We selected the articles that most adequately addressed this topic for inclusion in this review. RESULTS: Smoking significantly influences FeNO and negatively affects its concentration, although FeNO can distinguish steroid-naive asthmatic smokers from nonasthmatic smokers. Sputum neutrophilia is the predominant finding in induced sputum in asthmatic patients who smoke but inflammatory mediators derived either from neutrophils or from a T(H)1 response can also be measured in the supernatants. EBC gives the opportunity to evaluate neutrophil-derived cytokines, airway acidification, and plausible protective mechanisms in smoking asthma. CONCLUSIONS: Despite the encouraging updated results, the introduction of noninvasive techniques in daily clinical practice requires the reworking of some methodologic pitfalls and the identification of a reliable biomarker that is reproducible, possesses normal values, and provides information for the underlying inflammatory process and the response to treatment.     

Intranasal steroid reduces exhaled bronchial cysteinyl leukotrienes in allergic patients

BACKGROUND: Allergic rhinitis (AR) precedes and is often associated with bronchial asthma. Indeed, local and systemic inflammations in both conditions are very similar. Cysteinyl-leukotrienes (cys-LTs) are generated during early- and late-phase allergic reactions and induce smooth-muscle contraction, microvascular leakage, and mucous hypersecretion. Cys-LTs are detected in exhaled breath condensate (EBC) of asthmatics and regardless of bronchial symptoms, they are also found in EBC of rhinitic patients. OBJECTIVE: To evaluate cys-LTs in EBC of allergic patients and to assess the activity of nasal fluticasone propionate (FP) on EBC cys-LTs levels. METHODS: Cys-LTs coefficient of variation (CV) was evaluated from different EBC in 5 healthy volunteers. Cys-LTs levels from EBCs in 13 healthy controls and 56 allergic rhinitic (n=31) and rhinitic/asthmatic (n=25) patients were also evaluated at baseline. Subsequently patients were randomized to receive either FP 100 microg/day per nostril or placebo for 2 weeks and then re-evaluated for EBC cys-LTs. RESULTS: The CV was 14.12%. EBC cys-LTs in allergic patients were significantly higher than in healthy subjects (70.9 vs. 20.6 pg/mL (median), P<0.05), while it did not differ between asthmatic/rhinitic and purely rhinitic patients. Treatment significantly reduced cys-LTs (from 93.6 to 19.9 pg/mL, P<0.001). This effect was evident both in asthmatic/rhinitic and in rhinitic patients. CONCLUSION: Treatment of AR with FP significantly reduces the levels of cys-LTs, major noninvasive markers of lower airway inflammation, suggesting that upper and lower airway inflammation is present and should be thus treated as a whole in subjects with AR with and without asthma.     

Increased macrophage-derived chemokine in exhaled breath condensate and plasma from children with asthma

BACKGROUND: Type 2 helper T lymphocyte-specific chemokines including macrophage-derived chemokine (MDC), thymus and activation-regulated chemokine (TARC) and eotaxin are important mediators for allergic airway inflammation. OBJECTIVE: We investigated whether these chemokines can be detected in exhaled breath condensate (EBC) and their relation to childhood asthma. METHODS: Asthmatics recruited from paediatric clinics of a university teaching hospital were classified into intermittent asthma (IA) and persistent asthma (PA) according to Global Initiative for Asthma guidelines. EBC was collected by a disposable collection kit, whereas fractional exhaled nitric oxide (FENO) was measured by a chemiluminescence analyser. Concentrations of MDC, TARC and eotaxin in both EBC and plasma were measured using sandwich enzyme immunoassay. The intra-subject reproducibility of exhaled chemokine measurements was determined by co-efficients of variation (CV). RESULTS: Forty-eight patients with PA, 36 children with IA and 18 controls were recruited. MDC and eotaxin were present in EBC from nearly all subjects, whereas TARC could be measured in EBC from 33 (32%) subjects only. The median MDC concentration in EBC was higher in PA (117 pg/mL) as compared with IA (106 pg/mL) and controls (105 pg/mL; P=0.003 for both). The median plasma MDC concentration in PA (648 pg/mL) was also higher than that in IA (520 pg/mL; P=0.002) and controls (490 pg/mL; P=0.008). The median plasma TARC concentration was also increased in PA as compared with IA (72 pg/mL vs. 35 pg/mL; P=0.004). MDC concentrations in EBC were lower in patients with PA who received high-dose inhaled corticosteroid (P=0.005). FENO was significantly higher in asthmatics than controls (P<0.0001), but it was not associated with chemokines in EBC or plasma. The mean (range) CV for measuring MDC, TARC and eotaxin in EBC (n=6) were 5.5 (2.0-7.2%), 8.8 (3.6-14.4%) and 5.2 (2.8-7.9%), respectively. CONCLUSIONS: Our results suggest that MDC in EBC and MDC and TARC in plasma are increased in children with PA as compared with IA or control. MDC concentrations in EBC are suppressed in patients on high-dose inhaled corticosteroid treatment.     

Effects of inhaled corticosteroids on exhaled leukotrienes and prostanoids in asthmatic children

BACKGROUND: Lipid mediators play an important pathophysiologic role in atopic asthmatic children, but their role in the airways of atopic nonasthmatic children is unknown. OBJECTIVE: We sought (1) to measure leukotriene (LT) E 4 , LTB 4 , 8-isoprostane, prostaglandin E 2 , and thromboxane B 2 concentrations in exhaled breath condensate in atopic asthmatic and atopic nonasthmatic children; (2) to measure exhaled nitric oxide (NO) as an independent marker of airway inflammation; and (3) to study the effect of inhaled corticosteroids on exhaled eicosanoids. METHODS: Twenty healthy children, 20 atopic nonasthmatic children, 30 steroid-naive atopic asthmatic children, and 25 atopic asthmatic children receiving inhaled corticosteroids were included in a cross-sectional study. An open-label study with inhaled fluticasone (100 microg twice a day for 4 weeks) was undertaken in 14 steroid-naive atopic asthmatic children. RESULTS: Compared with control subjects, exhaled LTE 4 ( P <.001), LTB 4 ( P <.001), and 8-isoprostane ( P <.001) levels were increased in both steroid-naive and steroid-treated atopic asthmatic children but not in atopic nonasthmatic children (LTE 4 , P=.14; LTB 4 , P=.23; and 8-isoprostane, P=.52). Exhaled NO levels were increased in steroid-naive atopic asthmatic children ( P <.001) and, to a lesser extent, in atopic nonasthmatic children ( P <.01). Inhaled fluticasone reduced exhaled NO (53%, P <.0001) and, to a lesser extent, LTE 4 (18%, P <.01) levels but not LTB 4 , prostaglandin E 2 , or 8-isoprostane levels in steroid-naive asthmatic children. Conclusions Exhaled LTE 4 , LTB 4 , and 8-isoprostane levels are increased in atopic asthmatic children but not in atopic nonasthmatic children. In contrast to exhaled NO, these markers seem to be relatively resistant to inhaled corticosteroids.     

Noninvasive methods for the detection of upper and lower airway inflammation in atopic children

BACKGROUND: Exhaled nitric oxide (FE(NO)) and exhaled breath condensate (EBC) are noninvasive methods to assess inflammation. OBJECTIVE: To investigate the role of the FE(NO) and of the EBC pH and IL-5 levels in atopic children. METHODS: We evaluated oral and nasal FE(NO) and the pH and IL-5 of oral and nasal EBC in children with atopic dermatitis (AD; n = 18), allergic rhinitis (AR; n = 18), intermittent asthma (n = 21), moderate persistent asthma (n = 18), and healthy controls (HCs; n = 16). RESULTS: Oral FE(NO) was significantly increased in asthma, whereas the nasal values were increased in AR and asthma in comparison with HCs. The pH of oral EBC was lower in AD and asthma than in AR and HCs, whereas the nasal levels were lower in AD, AR, and asthma than in HCs. The oral IL-5 was higher in AD, AR, and asthma in comparison with HCs, whereas the nasal IL-5 concentrations were higher in asthma and AR than in HCs. In AR, the nasal FE(NO) correlated with the IL-5 values and with the disease duration. In intermittent asthma, oral and nasal pH inversely correlated with the exacerbations, whereas in moderate asthma, the nasal IL-5 positively correlated with exacerbations. In AD, the oral and nasal IL-5 positively correlated with the serum IgE. CONCLUSION: These markers of nasal and bronchial inflammation, accessible with noninvasive techniques, might be useful to identify patients with uncontrolled diseases and to verify the usefulness of new therapeutic approaches. CLINICAL IMPLICATIONS: These markers are useful tools to monitor the upper and lower airway inflammation in atopic children.     

Relationships between adult asthma and oxidative stress markers and pH in exhaled breath condensate: a systematic review

Oxidative stress has a recognized role in the pathophysiology of asthma. Recently, interest has increased in the assessment of pH and airway oxidative stress markers. Collection of exhaled breath condensate (EBC) and quantification of biomarkers in breath samples can potentially indicate lung disease activity and help in the study of airway inflammation, and asthma severity. Levels of oxidative stress markers in the EBC have been systematically evaluated in children with asthma; however, there is no such systematic review conducted for adult asthma. A systematic review of oxidative stress markers measured in EBC of adult asthma was conducted, and studies were identified by searching MEDLINE and SCOPUS databases. Sixteen papers met the inclusion criteria. Concentrations of exhaled hydrogen ions, nitric oxide products, hydrogen peroxide and 8‐isoprostanes were generally elevated and related to lower lung function tests in adults with asthma compared to healthy subjects. Assessment of EBC markers may be a noninvasive approach to evaluate airway inflammation, exacerbations, and disease severity of asthma, and to monitor the effectiveness of anti‐inflammatory treatment regimens. Longitudinal studies, using standardized analytical techniques for EBC collection, are required to establish reference values for the interpretation of EBC markers in the context of asthma.     

A fast, simple, and inexpensive method to collect exhaled breath condensate for pH determination.

BACKGROUND: Exhaled breath condensate (EBC) analysis is a noninvasive method for assessing lower airway inflammation. Various methods of collecting EBC have been described. However, they are often time-consuming or involve expensive equipment. OBJECTIVE: To evaluate the efficiency and repeatability of a simple, fast, and inexpensive method of EBC collection for pH determination. METHODS: Twenty-four mild asthmatic patients, 18 moderate-to-severe asthmatic patients, and 26 controls were asked to slowly exhale for 45 seconds into a -80 degrees C cooled metal cylinder covered with protective rubber and attached to a piece of tubing. The EBC was collected using a syringe's plunger. The groups were compared regarding EBC pH. Reproducibility tests were also performed. Induced sputum samples were obtained for inflammatory cell counts. RESULTS: We obtained approximately 50 microL of EBC for pH determination. Mild asthmatic patients had lower mean +/- SD pH values than controls (5.97 +/- 0.48 vs 6.36 +/- 0.34; P = .008), and corticosteroid-treated, moderate-to-severe asthmatic patients had mean +/- SD pH values similar to controls (6.23 +/- 0.38; P > .05). Mean +/- SD sputum eosinophil percentages were higher in both asthmatic groups than in controls (3.42% +/- 5.37% and 4.14% +/- 4.98% vs 0.04% +/- 0.12%; P < .001) and were not correlated with pH values in all groups. The mean intraday coefficient of variation for the method was 4.8% (range, 0.9%-8.8%). No correlation was found in all groups between sputum neutrophils and pH. CONCLUSIONS: We developed a useful device for collecting EBC for pH evaluation that could provide an alternative to other methods when pH is the main variable evaluated.     

Analysis of exhaled leukotrienes in nonasthmatic adult patients with seasonal allergic rhinitis

BACKGROUND: Leukotrienes (LTs) are increased in exhaled breath condensate (EBC) in patients with asthma. So far no data have been reported about LT levels in nonasthmatic patients with seasonal allergic rhinitis (SAR). The aim of the study was to find out whether the LT levels in EBC were increased in the nonasthmatic adult patients with SAR both during and after the pollen season in comparison with healthy controls and to assess the changes of the LT levels after the pollen season. METHODS: Twenty-nine nonasthmatic adult patients with SAR underwent measurement of exhaled LTs in the EBC during and after the pollen season. Leukotrienes B(4), C(4), D(4) and E(4) were analysed by a specific and sensitive gas chromatography/mass spectrometry (GC/MS) assay and compared with 50 healthy nonsmoking controls. Spirometry, skin prick tests and nonspecific IgE were evaluated. RESULTS: Leukotrienes concentrations (B(4), E(4) but not D(4)) were significantly increased in and after the pollen season in patients with SAR in comparison with healthy controls. In most of the samples, LT C(4) was undetectable. The values of all exhaled LTs were significantly decreased after the pollen season compared with the seasonal baseline: LTB(4) (P = 0.023), LTD(4) (P = 0.020), LTE(4) (P = 0.047). CONCLUSIONS: Levels of exhaled LTB(4) and LTE(4) were higher in SAR patients than in healthy controls and decreased after the pollen season as compared with levels in season. The SAR patients with the highest in season LT levels had also the post-season levels elevated and this may be an early marker of inflammatory process in the lower airways despite the absence of clinical symptoms of asthma.     

Airway cytokine expression measured by means of protein array in exhaled breath condensate: correlation with physiologic properties in asthmatic patients

BACKGROUND: Simultaneous monitoring of airway inflammation and physiology might be useful for asthma management. OBJECTIVE: We examined the upregulated molecules in asthmatic airways. Furthermore, we investigated the relationship between these molecules and the airway physiologic properties of asthma. METHODS: Ten nonsmoking healthy subjects and 16 steroid-naive asthmatic patients were enrolled. Exhaled breath condensate (EBC) sampling, spirometry, and methacholine inhalation challenge were performed on one occasion in this cross-sectional study. Peak expiratory flow was also measured for 4 weeks. Airway cytokine-chemokine-growth factor production was analyzed with a protein array. RESULTS: The expressions of IL-4, IL-8, IL-17, TNF-alpha, RANTES, IFN-gamma-inducible protein 10, TGF-beta, and macrophage inflammatory protein 1alpha and 1beta were significantly upregulated in asthmatic airways compared with those of nonsmoking healthy subjects. Among the upregulated molecules, RANTES expression was significantly correlated with the parameters that represent airway caliber, FEV(1) and respiratory resistance values. In addition, the levels of both TNF-alpha and TGF-beta were significantly correlated with the methacholine threshold and peak expiratory flow variability for the week. CONCLUSION: Inflammatory molecule analysis with EBC appeared to be useful for monitoring the asthmatic airway condition. CLINICAL IMPLICATIONS: Measurements of cytokine levels in EBC might be a promising approach to assess the efficacy of pharmacologic interventions and to investigate the pathophysiology of asthma.     

The effect of allergic rhinitis on adenosine concentration in exhaled breath condensate

BACKGROUND: Patients with allergic rhinitis (AR) frequently develop asthma. This initiating inflammation in the lower airways may result in increased levels of inflammatory mediators such as adenosine in the exhaled breath. OBJECTIVE: We compared adenosine levels in exhaled breath condensate (EBC) and both exhaled and nasal nitric oxide (NO) levels of AR patients and healthy control subjects. We also tested whether inhalation through inflamed nasal cavity during EBC sampling influences adenosine concentrations in exhaled air. METHODS: Exhaled and nasal NO levels were measured and EBC samples (at oral inhalation) were collected from 27 patients and 15 healthy controls. EBC collection was repeated after 15 min with subjects inhaling through their nose. Adenosine was measured by HPLC and NO was determined by chemiluminescence. RESULTS: The concentration of EBC adenosine was higher in patients with AR than in healthy controls (12.4+/-1.3 nM vs. 6.5+/-0.7 nM, P=0.0019) and this was accompanied by an increase in the concentration of exhaled NO (10.2+/-1.3 ppb vs. 5.3+/-0.5 ppb; P=0.0099, respectively). No difference in nasal NO was detected. EBC adenosine concentration showed a significant positive correlation with the level of exhaled NO. In contrast to healthy control subjects, patients with rhinitis had higher levels of exhaled adenosine when inhaling via the nose instead of the mouth (17.7+/-2.8 nM, P=0.007). CONCLUSION: When compared with healthy subjects, patients with AR exhibit an increased concentration of exhaled adenosine and a related increase in exhaled NO concentration. EBC adenosine is further increased when rhinitis patients inhale through their nose than via their mouth. Our data suggest that non-asthmatic patients with rhinitis may have subclinical inflammation in their lower airways.     

Exhaled nitric oxide and biomarkers in exhaled breath condensate indicate the presence, severity and control of childhood asthma

BACKGROUND: Exhaled nitric oxide and inflammatory biomarkers in exhaled breath condensate may be useful to diagnose and monitor childhood asthma. Their ability to indicate an asthma diagnosis, and to assess asthma severity and control, is largely unknown. OBJECTIVE: To study (1) the ability of exhaled nitric oxide and inflammatory markers in exhaled breath condensate (nitrite, nitrate, hydrogen peroxide, 8-isoprostane, IFN-gamma, TNF-alpha, IL-2, -4, -5, -10 and acidity) to discriminate between childhood asthma and controls. (2) The ability of these biomarkers to indicate asthma severity and control. METHODS: One-hundred and fourteen children were included: 64 asthmatics (10.7+/-3.0 years, 67.2% atopic) and 50 controls (10.0+/-0.4 years). Condensate was collected using a glass condenser. RESULTS: Exhaled nitric oxide, IFN-gamma and IL-4 in exhaled breath condensate differed significantly between asthma and controls. Multivariate backward logistic regression models demonstrated that IL-4 (odds ratio 7.9, 95% confidence interval 1.2-51.0) was the only significant indicator of an asthma diagnosis. Asthma control was best assessed by exhaled nitric oxide, 8-isoprostane, IFN-gamma and IL-4 (sensitivity 82%, specificity 80%, P<0.05), whereas exhaled nitric oxide, 8-isoprostane, nitrate and nitrite in condensate were the best indicators of asthma severity (sensitivity 89%, specificity 72%, P<0.05). CONCLUSION: Different markers in condensate are of an additional value to exhaled nitric oxide, and are needed in non-invasive inflammometry. They could be useful to diagnose asthma and to indicate asthma control and severity in childhood.     

Exhaled breath condensate levels of eotaxin and macrophage-derived chemokine in stable adult asthma patients

Background Asthma is associated with esoinophilic airway inflammation and overproduction of T‐helper type 2 (Th2) lymphocyte‐related cytokines. Objective This study assessed the eosinophil chemoattractant eotaxin and Th2‐specific macrophage‐derived chemokine (MDC) in the adult asthmatic airway. Eotaxin and MDC levels were determined in exhaled breath condensate (EBC) obtained from adult patients with asthma. Methods Fifty‐four asthmatics (20 male, mean (SD) age 40 (12) years and percentage predicted forced expiratory volume in 1 s (FEV₁) 81.7 (20.8)) and 20 age‐ and sex‐matched controls were studied. EBC was collected using EcoScreen by 10 min of tidal breathing with a nose clip. Concentrations of eotaxin and MDC were measured by ELISA. Results Asthma patients on inhaled corticosteroid (ICS) had a higher median interquartile range (IQR) level of eotaxin than the steroid‐naïve asthmatics (18.5 (17.7–20.1) vs. 17.9 (17.0–18.6) pg/mL, P=0.02) and controls (18.5 (17.7–20.1) pg/mL vs 17.4 (16.3–18.0) pg/mL, P=0.001). Eotaxin level in EBC had a significant negative correlation with the FEV₁/forced vital capacity ratio (r=?0.43, P=0.03) in steroid‐naïve asthmatics. EBC MDC level was higher in subjects on ICS than the steroid naïve asthmatics (120 (118–125) vs. 117 (116–119) pg/mL, P=0.01) and the controls (120 (118–125) vs. 117 (116–120) pg/mL, P=0.02). Conclusions Eotaxin and MDC could be measured in EBC of adults with asthma. EBC eotaxin and MDC levels were higher in asthmatics on ICS than the steroid‐naïve asthmatics or controls. Exhaled chemokines may be potential non‐invasive markers for assessing airway inflammation in asthmatics.     

Relationship between cysteinyl leukotriene in exhaled breath condensate and the severity of asthma in adult asthmatics in Japan]

BACKGROUND: The measurement of several mediators in exhaled breath condensate (EBC) can be useful as the biomarker for asthma. But there are a few reports about EBC of asthmatics in Japan. Aim: We examined the safety of the collection of EBC and the utility of cysteinyl leukotriene (cysLTs) in EBC as the biomarker of asthma. METHODS: Fifty-three asthmatics and eleven subjects without asthma were recruited. After the measuring of exhaled nitric oxide (eNO) and spirometory, EBC were collected. The levels of cysLTs in EBC were measurement by ELISA within 2 months. RESULTS: The collection of EBC did not induce any other symptoms in all subjects. In 48 subjects, the collection significantly increased their FEV1 and MMF level (DeltaFEV1: 2.27+/-0.77%, DeltaMMF 14.6+/-3.92% (mean+/-SEM). The level of cysLTs in EBC on asthmatics treated with high-dose ICS was significantly high compared with control group (p=0.0034), steroid-na?ve asthmatics or asthmatics treated with low-dose ICS (steroid naive vs. high dose ICS, p=0.041, low dose ICS vs. high dose ICS, p=0.021). The relationship between cysLTs in EBC and the levels of LTE4 in urine was significantly correlated (n=34, r=0.32, p=0.0435). The relationship between cysLTs in EBC and the levels of eNO was significantly correlated only in steroid-na?ve asthmatics (r=-0.57, p=0.0369). There was no relationship between cysLTs in EBC and FEV1, or log PC20Ach. CONCLUSION: The collection of EBC was perfectly non-invasive. The level of cysLTs can be useful as a biomarker of asthma.