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PubMed2006

Comparison of biomarkers in exhaled breath condensate and bronchoalveolar lavage.

RATIONALE: Exhaled breath condensate (EBC) is increasingly studied as a noninvasive research method of sampling the lungs, measuring several biomarkers. The exact site of origin of substances measured in EBC is unknown, as is the clinical applicability of the technique. Special techniques might be needed to measure EBC biomarkers. OBJECTIVES: To assess biomarker concentrations in clinical disease and investigate the site of origin of EBC, we compared EBC and bronchoalveolar lavage (BAL) biomarkers in 49 patients undergoing bronchoscopy for clinical indications. MEASUREMENTS: We measured exhaled nitric oxide, 8-isoprostane, hydrogen peroxide, total nitrogen oxides, pH, total protein, and phospholipid (n = 33) and keratin (n = 15) to assess alveolar and mucinous compartments, respectively. EBC was collected over 10 min using a refrigerated condenser according to European Respiratory Society/American Thoracic Society recommendations, and BAL performed immediately thereafter. RESULTS: 8-Isoprostane, nitrogen oxides, and pH were significantly higher in EBC than in BAL (3.845 vs. 0.027 ng/ml, 28.4 vs. 3.8 microM, and 7.35 vs. 6.4, respectively; p < 0.001). Hydrogen peroxide showed no difference between EBC and BAL (17.5 vs. 20.6 microM, p = not significant), whereas protein was significantly higher in BAL (33.8 vs. 183.2 microg/ml, p < 0.001). Total phospholipid was also higher in EBC, but keratin showed no difference. No significant correlation was found between EBC and BAL for any of the biomarkers evaluated either before or after correction for dilution. CONCLUSIONS: In clinical disease, markers of inflammation and oxidative stress are easily measurable in EBC using standard laboratory techniques and EBC is readily obtained. However, EBC and BAL markers do not correlate.

Biomarkers↗
PubMed2004

Comparison of single-breath and tidal breathing exhaled nitric oxide levels in infants.

The aim of this study was to compare two different methods, tidal breathing (TB) and single-breath (SB), for measuring fractional exhaled nitric oxide (FENO) in infants. FENO was measured in 71 infants with either recurrent wheeze (n=32), recurrent cough (n=16) or no symptoms (healthy, n=23) using both methods. For TB measurements five breaths were collected into a gas sampling bag (off-line reservoir sampling). The SB method was modified from the raised volume rapid thoraco-abdominal technique. Agreement between the two methods was investigated and both methods were used to compare FENO in infants with and without symptoms. Flow dependence of SB FENO was demonstrated using two expiratory flows (11 and 40 mL x s(-1)). There was a moderate correlation (r=0.60) but poor agreement between levels using the TB and SB methods. A significant difference in FENO between healthy children and children with wheeze was found using the SB but not the TB method. Due to lower expiratory flow and reduced nasal nitric oxide contamination the single-breath technique may be more sensitive than the tidal breathing method for detecting differences in exhaled nitric oxide between infants with and without respiratory symptoms.

Breath Tests↗
PubMed2004

An increase in exhaled nitric oxide is not associated with activity in pulmonary sarcoidosis.

Exhaled nitric oxide (eNO) concentration measurement may permit the noninvasive estimation of the severity of airways inflammation in respiratory tract diseases. The aim of this study was to evaluate the correlation between eNO concentration and the activity of sarcoidosis, its radiographic staging and lung function abnormalities. eNO concentration was measured using a chemiluminescent analyser in 27 patients with sarcoidosis and 11 control subjects. The mean eNO concentration in patients with sarcoidosis was significantly higher (6.7+/-0.50 parts per billion (ppb)) than that in the control group (5.17+/-0.73 ppb). eNO concentration was similar in radiographic stage I, II and III patients (6.53, 7.32 and 6.24 ppb, respectively). No significant difference was found in eNO concentration between the patients with active and inactive disease. Nor did eNO concentration differ between the patients with and without indication for therapy. There was no significant correlation between eNO concentration and forced vital capacity or bronchoalveolar lavage fluid lymphocyte and macrophage counts. There was a weak correlation between eNO concentration and single-breath carbon monoxide diffusing capacity of the lung. Exhaled nitric oxide concentration is elevated in patients with sarcoidosis. This concentration does not depend on the radiographic staging, activity or progression of the disease.

Adult↗
PubMed2006

Volatile organic compounds in the exhaled breath of young patients with cystic fibrosis.

Inflammatory mediators in the exhaled breath are receiving growing medical interest as noninvasive disease markers. Volatile organic compounds have been investigated in this context, but clinical information and methodological standards are limited. The levels of ethane, propane, n-pentane, methanol, ethanol, 2-propanol, acetone, isoprene, benzene, toluene, dimethyl sulphide (DMS) and limonene were measured in repeated breath samples from 20 cystic fibrosis patients and 20 healthy controls (aged 8-29 yrs). Three end-exhaled and one ambient air sample were collected per person and analysed on a customised gas chromatography system. Intra-subject coefficients of variation ranged between 9 and 34%, and hydrocarbon breath levels were influenced by their inspired concentrations. The alveolar gradient for pentane was higher in cystic fibrosis patients than in healthy controls (0.36 versus 0.21 ppb) and inversely proportional to forced expiratory volume in one second; highest values were observed in patients with pulmonary exacerbations (0.73 versus 0.24 ppb). Cystic fibrosis patients also exhibited a lower output of DMS (3.9 versus 7.6 ppb). Group differences were not significant for ethane and the remaining substances. It was concluded that chemical breath analysis for volatile organic compounds is feasible and may hold potential for the noninvasive diagnosis and follow-up of inflammatory processes in cystic fibrosis lung disease.

2-Propanol↗
PubMed2006

Real-time analysis of exhaled breath via resonance-enhanced multiphoton ionization-mass spectrometry with a medium pressure laser ionization source: observed nitric oxide profile.

An elevated concentration of nitric oxide (NO) in alveolar ventilation is indicative of inflammatory stress within the lung. We present here the first description of time-resolved measurement of NO in breath using photoionization mass spectrometry, providing new capabilities for the medical investigator, such as isotopic tracing. Here we use resonance-enhanced multiphoton ionization (REMPI) with time-of-flight mass spectrometry (TOF-MS) coupled with a medium pressure laser ionization (MPLI) source for the selective detection of NO in breath. To demonstrate this technology, a single male subject breathes NO-free air for several minutes, and then the exhaled breath is monitored. The ability of REMPI to differentiate among three different isotopomers of NO is demonstrated, and then the concentration profile of NO in exhaled breath is measured. A similar time-dependence concentration is found as observed by previous techniques. The advantages of this approach compared to other techniques are: (1) parts-per-billion by volume (ppbV) mixing ratios of NO can be measured on a sub-second time scale, (2) since the technique operates optically as well as mass-resolved, isotopomers of NO are discernable, permitting the use of isotopic tracing, and (3) other biologically significant gas molecules can be measured via REMPI.

Algorithms↗
PubMed2004

Exhaled markers of inflammatory lung diseases: ready for routine monitoring?

Assessing airway inflammation is important for investigating the underlying mechanisms of many lung diseases, including asthma and chronic obstructive pulmonary disease (COPD). Yet these are not measured directly in routine clinical practice because of the difficulties in monitoring inflammation. The presence and type of airway inflammation can be difficult to detect clinically, and may result in delays in initiating appropriate therapy. Non-invasive monitoring may assist in differential diagnosis of lung diseases, assessment of their severity and response to treatment. There is increasing evidence that breath analysis may have an important place in the diagnosis and clinical management of asthma, COPD, primary ciliary dyskinesia (PCD) and other major lung disease. The article reviews whether current noninvasive measurements of exhaled gases, such as nitric oxide (NO), hydrocarbons, inflammatory markers exhaled breath condensate (EBC) are ready for routine use in clinical practice.

Alkanes↗
PubMed2004

Assessment of exhaled gases in ventilated preterm infants.

Hydrogen peroxide (H2O2) production in exhaled air was measured in ventilated preterm newborns at 5, 24 and 48 hours after delivery, using originally designed method of exhaled breath condensate (EBC) collection. H2O2 production in expired gas was 812+/-34 pmol/20 min during the first measurement and then declined to 389+/-21 at 24 hours and 259+/-26 pmol/20 min at 48 hours.

Breath Tests↗
PubMed2004

[The effect of asthma and COPD exacerbation on exhaled nitric oxide (FE(NO))].

UNLABELLED: Exhaled nitric oxide is a marker of airway inflammation and it is significantly decreased by glucocorticosteroid therapy, especially in patients with asthma. AIM OF THE STUDY: Evaluation of changes in FE(NO) in asthma and COPD exacerbation. MATERIALS AND METHODS: 17 patients with acute asthma and 19 patients with an exacerbation of COPD were enrolled to the study. FE(NO) (chemiluminescence, on-line, restricted breath technique measurement in accordance with the ATS recommendations) was performed for five consecutive days following admission to hospital. Results of the following additional blood investigations: peripheral white blood cell count, ESR, C-reactive protein level, arterial blood gases, spirometry or peak expiratory flow were also analyzed. RESULTS: The average value of FE(NO) on admission was 41.5+/-10.7 ppb (95% CI: 18.8-64.2 ppb) asthma patients and 28.6+/-5.4 ppb (95% CI: 17.4-40.0 ppb) in COPD patients. In asthma patients a significant decrease of FE(NO) on the third day of therapy was observed (41.5 vs 26.1 ppb, p < 0.05). We found a positive correlation between FE(NO) on admission and the peripheral blood eosinophil count. In COPD patients a significant decrease of FE(NO) on the 4th day was noted (28.6 vs 17.5 ppb, p < 0.05). FE(NO) in both groups was higher than that of 19 healthy volunteers previously studied in our laboratory (14.1+/-4.7 ppb; 95% CI: 11.8+/-16.4 ppb). CONCLUSIONS: Exacerbations of asthma and COPD are associated with an increased FE(NO). FE(NO) measurement is a useful tool in the assessment of treatment efficacy. Exhaled nitric oxide may indicate the intensity of allergic inflammation in patients with asthma.

Acute Disease↗
PubMed2005

[The interleukin-6 level in exhaled breath condensate of patients with obstructive sleep apnea-hypopnea syndrome].

OBJECTIVE: To explore whether the airway inflammation marker in exhaled breath condensate is increased in obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: Thirty-one patients with OSAHS (15 smokers and 16 non-smokers) and 10 healthy age-matched and weight-matched controls were included in the study. Exhaled breath condensate (EBC) was collected before and after sleep at the same night from both groups. Interleukin-6 (IL-6) in EBC was measured by a specific enzyme immunoassay. RESULTS: (1) There was no difference in the pre-sleep IL-6 level among OSAHS smoker group, OSAHS non-smoker group and the control subjects (F = 0.515, P > 0.05). Compared with the level of pre-sleep [(2.5 +/- 1.0) ng/L in OSAHS smoker, and (2.3 +/- 0.8) ng/L in OSAHS non-smoker], the post-sleep level of IL-6 was elevated significantly in EBC from OSAHS patients of non-smokers [(3.1 +/- 1.2) ng/L] and smokers [(3.7 +/- 1.9) ng/L, P < 0.05]. Nevertheless, IL-6 level from the control group showed a reverse change. IL-6 was decreased significantly [(2.0 +/- 0.8) ng/L in pre-sleep vs (2.7 +/- 1.0) ng/L in post-sleep] after sleep in this group. There was no difference in post-sleep IL-6 level between OSAHS smokers [(3.7 +/- 1.9) ng/L] and non-smokers [(3.1 +/- 1.2) ng/L, P > 0.05]. A significant higher IL-6 level was observed in both OSAHS smokers [(3.7 +/- 1.9) ng/L] and non-smokers [(3.1 +/- 1.2) ng/L] compared with the controlled group [(2.0 +/- 0.8) ng/L, P < 0.05]. IL-6 level in EBC was correlated positively with AHI (r = 0.441, P < 0.05), ODI(4) (r = 0.533, P < 0.05), and negatively with minimal oxygen saturation (r = -0.529, P < 0.05). CONCLUSIONS: These findings suggest that inflammation was characteristic in the airways of OSAHS patients. Nocturnal hypoxia could be responsible for this change. The levels of IL-6 in EBC are associated with the severity of OSAHS and may prove to be useful in monitoring of airway inflammation in OSAHS.

Adult↗
PubMedDate not supplied

[Determination of NO2-/ NO3- in exhaled breath condensate. Zinc-catalyzed nitrate reduction].

Analysis of exhaled breath condensate (EBC) is a new prospective method for monitoring of inflammation and oxidative stress in lungs. The most extensively studied exhaled biomarker is nitric oxide (NO). It has very short life span and is converted into nitrites (NO2-) and nitrates (NO3-). In this study the level of NO2- and total level of NO2-/NO3- have been measured in EBC of smokers and non-smokers. Prior determination of NO2-/NO3- the nitrates were reduced to nitrites with zinc, and total level of NO2- was detected by Griess reaction. The mean concentrations of NO2 in EBC of non-smokers and smokers were 2.9 +/- 0.22 Mmol/ vs. 8.5 +/- 1.2 Mmol/l (mean +/- SD, p < 0.001). The level of total nitrites NO2-/NO3- was also higher in smokers (5.65 +/- 0.68 vs. 14.6 +/- 1.43; p < 0.001). Variability index was 8%. Recovery of NO3- from standard solutions was 93.4 +/- 9.6%, and 91.6 +/- 8.9% from EBC. We recommend zinc reduction as good and simple method for NO3- determination in EBC.

Adult↗
PubMed2005

[Exhaled hydrogen peroxide (H2O2) in allergic and non-allergic stable mild asthmatic children].

The evaluation of breath condensate (BC) composition is a new, non-invasive method studying inflammation processes in several respiratory diseases. Among many inflammation markers, hydrogen peroxide (H2O2) is the most common one, and its increased level was found in BC of cystic fibrosis and asthma patients. As in children's asthma, H2O2 is present and could correlates with the severity of the disease. The aim of our study was to check whether there exist differences between levels of H2O2 in children with allergic and non-allergic asthma. 83 allergic and 33 non-allergic children with mild asthma (50 girls and 66 boys, aged 7-17 years) were included in the study. All patients were clinically stable and used inhaled corticosteroids daily, and an inhaled bronchodilator on demand. Exhaled BC was obtained by spontaneously tidal volume breathing with EcoScreen (Jaeger, Germany). The content of H2O2 in the BC was measured spectrofluorometrically (homovanillic acid method). All subjects underwent flow-volume measurements immediately after collection of the condensate. Lung function in asthmatic allergic and non-allergic children showed near normal values and did not differ between groups. In the allergic group, the median H2O2 level in the expired condensate was 0.238 (0-1.86) microM, and in non-allergic 0.192 (0-0.78) microM (p > 0.05). We conclude that hydrogen peroxide in exhaled breath condensate of children with stable mild asthma does not differ significantly in allergic and non-allergic children and activity of airway inflammation seems to independent on allergic status of patients.

Adolescent↗
PubMed2006

Potential confounding factors in measurement of exhaled nitric oxide.

Nitric oxide is present in the exhaled air. Factors affecting the level of exhaled nitric oxide (exNO), except for smoking, are not well defined. In this study we seek to determine whether age, gender, body mass index (BMI), part of the day, or time after a meal could modulate exNO levels. exNO was examined by the use of a chemiluminescence method in 100 subjects - 31 women (19 nonsmokers and 12 smokers) and 69 males (55 nonsmokers and 14 smokers). Forty four subjects took medications due to stable coronary disease, 22 were after heart transplantation, and 34 did not take any drugs. We found that exNO levels did not differ either between the whole groups of women and men or between smokers and nonsmokers of either respective group (4.91 +/-2.38 vs. 6.27 +/-4.23 ppb; 3.21 +/-1.16 vs. 3.71 +/-1.55 ppb; 5.98 +/-2.35 vs. 6.92 +/-4.45 ppb). The correlation of exNO with age in the whole population was weak (r=0.23; P=0.02) and insignificant in the smoking and nonsmoking subgroups. Likewise, correlations of exNO with BMI, part of the day, or time after a meal were insignificant in whole population as well as the subgroups. We conclude that the aforementioned factors are not able to confound the measurement of exNO in the population studied.

Breath Tests↗
PubMed2006

Inflammatory markers in the exhaled breath condensate of patients with pulmonary sarcoidosis.

Pulmonary sarcoidosis may progress to fibrosis in some patients, so that close monitoring of its activity is essential for recommending clinical strategy. Examination of airway inflammatory markers in bronchoalveolar lavage (BAL) is one of the methods applied to assess the disease severity. Recently, the expired breath condensate (EBC) has become another source of cytokines and mediators. In sarcoidosis, except for NO and oxidative stress markers, no other mediators have yet been estimated in the exhaled air. In the present study we attempted to answer the question of whether airway inflammatory markers in pulmonary sarcoidosis patients might be assessable in EBC and to what extend these markers might reflect the disease activity in the lungs IL-6, TNF-alpha, PAI-1, and IGF-1 were measured by Elisa method in EBC and BALF samples from 9 patients with newly-diagnosed pulmonary sarcoidosis. TNF-alpha, IGF-1, and PAI-1 levels in EBC and BAL samples were comparable and closely positively correlated [TNF-alpha (r=0.79, P<0.001), IGF-1 (r=0.94, P<0.001), and PAI-1 (r=0.81, P<0.001)]. In contrast, IL-6 concentration in EBC was significantly lower compared with that in BALF, while the correlation between both materials was negative (r=-0.47, P<0.05). An important distinction in IL-6 performance, which might explain this inconsistency, is its tendency to form more complex molecular forms of a higher weight than that of other cytokines. Our study shows that EBC reflects cytokine production in the lung as effectively as BALF, providing that the characteristics of proteins evaluated allow their easy transfer into the exhaled air. Further studies are required before accepting EBC samples as an equivalent to BALF.

Adult↗
PubMed1999

Exhaled nitric oxide measurements in childhood asthma: techniques and interpretation.

In this review, we outline the role of nitric oxide in airway inflammation in children with asthma. We also discuss the various methods reported for measuring exhaled nitric oxide and provide some insight as to the pros and cons and pitfalls of these techniques. Guidelines for measurements of exhaled nitric oxide based on our experience are provided, as well as suggestions for the use of this technique as a new "airway inflammation test."

Asthma↗
PubMedDate not supplied

Biological monitoring of occupational exposure to isoflurane by measurement of isoflurane exhaled breath.

The relationship between isoflurane environmental concentrations in operating rooms and the corresponding isoflurane concentration in the exhaled air of the operating personnel at the end of the exposure has been investigated. Isoflurane was retained in an adsorbent cartridge and after thermal desorption the concentration was estimated by gas chromatography. Significant correlation between environmental and exhaled air isoflurane concentrations allowed the establishment of a biological exposure index and biological exposure limits corresponding to proposed atmospheric threshold values.

Air↗
PubMed1995

Collection of a single alveolar exhaled breath for volatile organic compounds analysis.

Measurement of specific organic compounds in exhaled breath has been used as an indicator of recent exposure to pollutants or as an indicator of the health of an individual. A typical application involves the collection of multiple breaths onto a sorbent cartridge or into an evacuated canister with the use of a relatively complex sampling apparatus. A new method has been developed wherein a single exhaled breath is directly transferred from the mouth into an evacuated 1 l or 1.8 l stainless steel SUMMA canister. The single breath canister (SBC) method avoids the necessity for a complex sampling system requiring maintenance and cleaning and allows easy collection of samples. Additionally, it is possible to collect a rapid sequence of samples from a subject to establish the elimination curve subsequent to an exposure to specific volatile organic compounds with a theoretical resolution of adjacent breaths. The SBC method was compared to an accepted canister based sampling system to assure comparability and then used to demonstrate its utility by measuring the absorption and elimination of chloroform during and after exposure to chlorinated shower water.

Breath Tests↗
PubMed2003

Exhaled nitric oxide and tracheal endothelin-1 in preterm infants with and without RDS.

We measured exhaled nitric oxide and tracheal aspirate endothelin-1 to determine relationships between these substances and alterations in pulmonary gas exchange during respiratory distress syndrome (RDS) in comparison to those obtained from control preterm infants without RDS. Eight infants with RDS had measurements made at 24 hr and again at 48-72 hr. Eight control infants were studied once at 24-48 hr of life. Exhaled gas was analyzed on-line, and minute excretion of NO (V(NO)) was calculated. ET-1 was determined by immunoassay. Median V(NO) at 24 hr in RDS was 0.405 nl/min/kg (range, 0.30 -0.79), which subsequently declined by 48-72 hr to 0.166 nl/min/kg (P < 0.01). The V(NO) in RDS infants was significantly higher than time-matched V(NO) in controls, with a median of 0.099 nl/min/kg (range, 0.03-0.27; P < 0.001). ET-1 was not correlated with initial V(NO) in the RDS or control patients. In conclusion, in RDS, V(NO) decreases as gas exchange improves. ET-1 is detectable in tracheal aspirate samples in both groups of infants.

Body Fluids↗
PubMed2003

Exhaled nitric oxide is age-dependent in asthma.

We determined whether the exhaled nitric oxide (eNO) level in asthmatics is age-dependent. Eighty-seven asthmatic patients aged 2-41 years were studied. Hyperreactivity to adenosine 5'-monophosphate (AMP) was used to confirm asthma (</= 200 mg/ml). In the younger group of children (2-5 years), AMP challenge was performed by the provocation concentration causing wheeze (PCW) method, while in the older groups of patients (6-41 years), regular spirometry was used. Exhaled NO was measured in the younger group by the tidal breathing method (TBm) and in the older subjects by the slow vital capacity method (SVCm). TBm and SVCm were compared in 21 other subjects, and there was a significant correlation between the two values (r = 0.96, P < 0.0001). The equation of correlation between the two methods was eNOTBm = 0.78eNOSVCm - 0.51. Within asthmatic patients, we found a significant increase in eNO with age (P < 0.0001), while there was no significant difference in AMP reactivity (P = 0.35). We conclude that eNO in asthmatic patients is age-dependent, with lower values in young children.

Adenosine Monophosphate↗