Exhaled Breath Condensate pH Research Articles

Exhaled breath condensate hydrogen peroxide, pH and leukotriene B4 are associated with lower airway inflammation and airway cytology in the horse.

Exhaled breath condensate (EBC) analysis is a noninvasive method to assess the lower respiratory tract. In human subjects, EBC hydrogen peroxide (H2 O2 ), pH and leukotriene B4 (LTB4 ) are useful for detection and monitoring of inflammatory lung diseases, including asthma. To determine associations between EBC biomarkers and cytological and endoscopic definitions of lower airway inflammation (LAI) while controlling for sampling and environmental variables. Prospective, cross-sectional study. Clinical, endoscopic and airway cytological findings from 47 horses were compared with EBC pH and concentrations of H2 O2 and LTB4 by univariate and multivariable analyses. Dichotomous (presence/absence of airway inflammation) and continuous outcome variables (differential cell counts in tracheal aspirate and bronchoalveolar lavage fluid, BALF) were evaluated and potential effects of collection and methodological factors were included. EBC pH and H2 O2 concentrations were higher in horses with LAI and both were positively associated with the percentage of neutrophils in BALF (P<0.05). Mast cell percentage in BALF was negatively associated with EBC pH, and BALF eosinophil percentage was positively associated with EBC LTB4 (P<0.05). Ambient temperature, relative humidity and assay methodology significantly impacted some analytes. LAI is challenging to categorise due to a variety of clinical and cytological phenotypes. Although the study was designed to overcome this limitation, numbers of horses were small in some categories. EBC pH and H2 O2 concentrations are altered by airway inflammation, suggesting a role for these biomarkers in the diagnosis and monitoring of airway disease. Environmental and methodological factors can influence these biomarkers and should be considered in the interpretation of results.

Study of Various Parameters that Influence the Content of Exhaled Breath Condensate Used in the Diagnosis of Gastroesophageal Reflux Disease

Abstract In this work, various parameters that influence the ionic content and pH of exhaled breath condensate in of the noninvasive diagnosis of gastroesophageal reflux disease were studied. Exhaled breath condensate samples were collected using a miniature and inexpensive sampling device. Capillary electrophoresis with contactless conductometric detection was used to monitor the ionic content of exhaled breath condensate. Background electrolyte composed of 20 mM of 2-(N-Morpholino)ethanesulfonic acid, 20 mM of L-Histidine, 2 mM of 18-Crown-6 and 30 M of cetyltrimethylammonium bromide facilitated the rapid separation of anions and cations, both in less than 2 minutes. The possibility of contamination of the exhaled breath condensate by saliva is discussed in detail. The day-to-day repeatability (n=5) of the ionic content and pH of the exhaled breath condensate was studied and was satisfactory, reflecting mainly the physiological variability

Su1073 - Assessment of Exhaled Breath Condensate for Non-Invasive Diagnosis of Gastroesophageal Reflux Disease

Introduction: Gastroesophageal reflux disease (GERD) is a disease caused by backflow of gastric contents into the esophagus due to the failure of physiological antireflux mechanisms and can lead to esophageal and extraesophageal symptomatology. Extraesophageal reflux (EER) is a condition where refluxate penetrate above the upper esophageal sphincter in to the oral cavity, pharynx, upper and lower respiratory tract and leads to pathological changes. Monitoring of various parameters in exhaled breath condensate (EBC) in patients suffering from extraesophageal symptoms of GERD is non-invasive and simple approach to assess the gastroesophageal reflux. The aim was to compare the pH and total ionic profile of EBC with 24-hour multichannel intraluminal impedance and pH monitoring (MII-pH) and Peptest in a group of patients with acid reflux (pH<4), weakly acid reflux (pH 4-7) and healthy controls

Exhaled Breath Condensate: Pilot Study of the Method and Initial Experience in Healthy Subjects.

Analysis of Exhaled breath condensate (EBC) is a re-discovered approach to monitoring the course of the disease and reduce invasive methods of patient investigation. However, the major disadvantage and shortcoming of the EBC is lack of reliable and reproducible standardization of the method. Despite many articles published on EBC, until now there is no clear consensus on whether the analysis of EBC can provide a clue to diagnosis of the diseases. The purpose of this paper is to investigate our own method, to search for possible standardization and to obtain our own initial experience. Thirty healthy volunteers provided the EBC, in which we monitored the density, pH, protein, chloride and urea concentration. Our results show that EBC pH is influenced by smoking, and urea concentrations are affected by the gender of subjects. Age of subjects does not play a role. The smallest coefficient of variation between individual volunteers is for density determination. Current limitations of EBC measurements are the low concentration of many biomarkers. Standardization needs to be specific for each individual biomarker, with focusing on optimal condensate collection. EBC analysis has a potential become diagnostic test, not only for lung diseases.

Analysis of Exhaled Breath Condensate pH in Asthma among Indian Population–A Pilot Study

Analysis of Exhaled Breath Condensate pH in Asthma among Indian Population–A Pilot Study

Remote Ischemic Preconditioning Decreases Oxidative Lung Damage After Pulmonary Lobectomy: A Single-Center Randomized, Double-Blind, Controlled Trial.

During lobectomy in patients with lung cancer, the operated lung is often collapsed and hypoperfused. Ischemia/reperfusion injury may then occur when the lung is re-expanded. We hypothesized that remote ischemic preconditioning (RIPC) would decrease oxidative lung damage and improve gas exchange in the postoperative period. We conducted a single-center, randomized, double-blind trial in patients with nonsmall cell lung cancer undergoing elective lung lobectomy. Fifty-three patients were randomized to receive limb RIPC immediately after anesthesia induction (3 cycles: 5 minutes ischemia/5 minutes reperfusion induced by an ischemia cuff applied on the thigh) and/or control therapy without RIPC. Oxidative stress markers were measured in exhaled breath condensate (EBC) and arterial blood immediately after anesthesia induction and before RIPC and surgery (T0, baseline); during operated lung collapse, immediately before resuming two-lung ventilation (TLV) (T1); immediately after resuming TLV (T2); and 120 minutes after resuming TLV (T3). The primary outcome was 8-isoprostane levels in EBC at T1, T2, and T3. Secondary outcomes included the following: NO2+NO3, H2O2 levels, and pH in EBC and in blood (8-isoprostane, NO2+NO3) and pulmonary gas exchange variables (PaO2/FiO2, A-aDO2, a/A ratio, and respiratory index). Patients subjected to RIPC had lower EBC 8-isoprostane levels when compared with controls at T1, T2, and T3 (differences between means and 95% confidence intervals): -15.3 (5.8-24.8), P = .002; -20.0 (5.5-34.5), P = .008; and -10.4 (2.5-18.3), P = .011, respectively. In the RIPC group, EBC NO2+NO3 and H2O2 levels were also lower than in controls at T2 and T1-T3, respectively (all P < .05). Blood levels of 8-isoprostane and NO2+NO3 were lower in the RIPC group at T2 (P < .05). The RIPC group had better PaO2/FiO2 compared with controls at 2 hours, 8 hours, and 24 hours after lobectomy in 95% confidence intervals for differences between means: 78 (10-146), 66 (14-118), and 58 (12-104), respectively. Limb RIPC decreased EBC 8-isoprostane levels and other oxidative lung injury markers during lung lobectomy. RIPC also improved postoperative gas exchange as measured by PaO2/FiO2 ratio.

The consistency and influence of environmental and animal factors on exhaled breath condensate hydrogen peroxide, pH and leukotriene B4 in horses

This study was performed to determine the consistency of exhaled breath condensate (EBC) hydrogen peroxide (H2O2), pH and leukotriene B4 (LTB4) measurements in asymptomatic horses and to define the influence of environmental and animal factors on these variables. Intra- and inter-day consistency for both H2O2 and pH measurements were adequate, with intraclass correlation coefficients ≥0.8, whereas the consistency for LTB4 was poor. H2O2 was influenced by ambient temperature (TA), humidity, time of day and collection location (all P<0.01), while pH was influenced by respiratory rate during EBC collection and TA (both P<0.001). The consistency of EBC H2O2 and pH measurements may be sufficient for use as diagnostic biomarkers in horses. However, the influence of identified environmental and animal factors should be considered.

Mycoplasma pneumoniae and health outcomes in children with asthma

BackgroundAcute infections with Mycoplasma pneumoniae (Mp) have been associated with worsening asthma in children. Mp can be present in the respiratory tract for extended periods; it is unknown whether the long-term persistence of Mp in the respiratory tract affects long-term asthma control. ObjectiveTo determine the effect of Mp on asthma control. MethodsWe enrolled 31 pediatric subjects 3 to 10 years of age with persistent asthma who completed up to 8 visits over a 24-month period. We detected Mp by antigen capture and polymerase chain reaction. Primary outcome measurements included symptom scores, quality of life, medication scores, oral corticosteroid use, health care usage, school absences, and exhaled breath condensate pH. ResultsLow levels of Mp community-acquired respiratory distress syndrome toxin were detected in 20 subjects (64.5%) at enrollment. Subjects with Mp positivity at a given visit had a .579 probability of remaining Mp positive at the subsequent visit, whereas those with Mp negativity had a .348 probability of becoming Mp positive at the following visit. The incidence of Mp overall was higher in the spring and summer months. Overall, we found no significant relation between the detection of Mp and worse outcome measurements at the same visit or at subsequent visits. ConclusionThe long-term persistence of Mp in the respiratory tract is common in children with asthma. However, the detection of Mp was not associated significantly with worse asthma symptoms, quality of life, health care usage, school absences, or exhaled breath condensate pH in this pediatric asthma cohort.

Exhaled Breath Condensate Acidification Occurs During Surgery for Abdominal Cancer.

Acidification of exhaled breath condensate (EBC), reflecting airway inflammation and oxidative stress, has been reported in lung cancer patients undergoing lobectomy. We undertook this study to examine EBC pH changes during surgery for abdominal cancer. EBC pH was measured from 20 patients undergoing abdominal cancer resection before and during surgery. Repeated-measures of ANOVA and random-effects linear models were applied to compare mean EBC pH values in samples collected at different times. Cox and linear regression models were used to determine the association of EBC pH with occurrence of acute bronchospasm intra-operatively and the duration of hospitalization. Significant acidification of EBC was observed during surgery (p=0.007) associated with 0.77% (95% confidence interval=-0.14-1.68, p-value=0.097) increase in the risk for developing acute bronchospasm, after adjustment for potential confounders. EBC acidification occurs in patients undergoing abdominal cancer resection and is associated with the occurrence of acute bronchospasm intraoperatively.

Impact of Internal and External Factors on EBC-pH and FeNO Changes in Humans Following Challenge with Ethyl Acrylate.

Acute effects of ethyl acrylate exposure at 5 ppm for 4 h include changes of pH in exhaled breath condensate (EBC-pH) and exhaled nitric oxide (FeNO). So far, few data have been reported for atopic persons or the impact of the exposure conditions on biomarkers, e.g., constant versus variable application of irritants. Nine atopic and eighteen healthy volunteers without bronchial hyperresponsiveness were exposed for 4 h to ethyl acrylate concentrations of 0.05 ppm (sham), 5 ppm (constant concentration), and 0-10 ppm (variable, mean concentration of 5 ppm) in an exposure laboratory. A positive atopic status was defined according to specific IgE concentrations to common inhalant allergens (sx1 ≥ 0.35 kU/L). Biomarker levels were assessed before and after challenge and adjusted for levels after sham exposure (net response). Ethyl acrylate at constant, but not at variable concentrations induced a significant change in the net responses of EBC-pH and FeNO. Concerning FeNO, this could be observed only for atopic persons. The changes of biomarker levels were related to their baseline values. Biomarker responses to challenge with ethyl acrylate may be influenced by the patterns of application as well as baseline airway inflammation and atopic status of the volunteers.

Association of Asthma Symptoms and Exacerbation with Inflammatory Biomarkers

Objective: To investigate a relationship of asthma symptoms and exacerbations with systemic (high-sensitivity Creactive protein (hs-CRP), eosinophilic cationic protein (ECP), leukocytes) and local (exhaled NO (FENO), pH and urates in exhaled breath condensate (EBC) and exhaled breath temperature (EBT)) inflammatory biomarkers (BMs) in asthmatic children. Methods: This cross-sectional study comprised 93 consecutive asthmatic patients (age 6-18 years, 22 girls) with mild intermittent asthma ((IA), N=44) and mild to moderate persistent asthma ((PA), N=49). Medical history (asthma symptoms and exacerbation), pulmonary function, FENO, EBT, samples of exhaled breath and peripheral blood were collected. Results: Local BMs (EBC urates and EBT) showed stronger correlation with asthma symptoms then systemic BMs (hs-CRP, blood count with differencials) (r=0.26-0.68, r=0.06-0.32, p<0.05; respectively). Single measurements of inflammatory BMs are not good predictors for future asthma exacerbation (binary logistic regression; χ²=13.9; df=11; p=0.238). Conclusion: Study of combination of various exhaled breath and exhaled breath condensate BMs should continue, especially in longitudinal studies with repeated measurements of BMs.

Valor pronóstico del pH en el condensado de aire exhalado y de la fracción exhalada de óxido nítrico en la enfermedad pulmonar intersticial asociada a esclerosis sistémica

IntroductionInterstitial lung disease (ILD) is one of the major causes of death in systemic sclerosis (SSc). This study investigated exhaled breath (EB) and exhaled breath condensate (EBC) biomarkers in patients with SSc and analyzed their role as a prognostic tool in SSc-related ILD. MethodsFraction exhaled nitric oxide (FeNO) and exhaled carbon monoxide (eCO) measured in EB, together with pH, nitrite, nitrate and interleukin-6 levels measured in EBC were prospectively analyzed in 35 patients with SSc. Twelve patients had established ILD by chest high-resolution computed tomography (HRCT), and 23 patients showed no evidence of ILD. EB and EBC biomarkers were determined at inclusion, and pulmonary function tests were annually performed during 4 years of follow-up. ResultsNo differences at baseline biomarkers levels were found between groups. In all patients studied, low EBC pH levels were associated with a decreased diffusing capacity for carbon monoxide (DLCO) during follow-up. Low FeNO levels were correlated with lower forced vital capacity (FVC) at baseline, 4years of follow-up and with a decrease in FVC and DLCO during monitoring. Among ILD patients, high eCO levels were correlated with lower baseline FVC. In the global cohort, a worse progression-free survival was identified in patients with EBC pH values lower than 7.88 and FeNO levels lower than 10.75ppb (Log Rank P=.03 and P<.01, respectively). ConclusionsEB and EBC could help to detect patients likely to present a deterioration on lung function during follow up.

Exhaled breath condensate pH and cysteinyl leukotriens in patients with chronic cough secondary to acid gastroesophageal reflux

Chronic cough is one of the most common clinical problems and it may be secondary to different stimuli and diseases, including low-level physical and chemical stimulation of the esophageal–bronchial reflex, suggestive of cough-reflex hyperresponsiveness, in patients with gastroesophageal reflux; however, it is still debated whether gastroesophageal reflux could induce airway inflammation and acidification. The aim of this study was to investigate airway pH and cysteynil-leukotrienes (Cys-LTs) concentration (a marker of airway inflammation) in exhaled breath condensate (EBC). Patients with chronic cough and for which all known causes, excluding gastroesophageal reflux, had been investigated and ruled out, were enrolled in the study. All patients underwent 24 h pH monitoring, and EBC was collected to assess pH and Cys-LTs concentration. Forty-five patients were included in the study and those with gastroesophageal reflux had significantly lower EBC-pH and higher concentration of EBC-Cys-LTs. There was a linear inverse correlation between EBC-pH values and EBC-Cys-LTs logarithmically transformed, and a multivariate analysis confirmed that the only significant determinat variable of EBC-Cys-LTs was the presence of gastroesophageal reflux. This study adds knowledge on possible mechanisms related to chronic cough associated with gastroesophageal reflux, which seems to be strictly dependent on airway acidification and the production of Cys-LTs, therefore suggesting an underlying neurogenic inflammation with tachykinins involvement.

Prognostic Role of Exhaled Breath Condensate pH and Fraction Exhaled Nitric Oxide in Systemic Sclerosis Related Interstitial Lung Disease

IntroductionInterstitial lung disease (ILD) is one of the major causes of death in systemic sclerosis (SSc). This study investigated exhaled breath (EB) and exhaled breath condensate (EBC) biomarkers in patients with SSc and analyzed their role as a prognostic tool in SSc-related ILD. MethodsFraction exhaled nitric oxide (FeNO) and exhaled carbon monoxide (eCO) measured in EB, together with pH, nitrite, nitrate and interleukin-6 levels measured in EBC were prospectively analyzed in 35 patients with SSc. Twelve patients had established ILD by chest high-resolution computed tomography (HRCT), and 23 patients showed no evidence of ILD. EB and EBC biomarkers were determined at inclusion, and pulmonary function tests were annually performed during 4 years of follow-up. ResultsNo differences at baseline biomarkers levels were found between groups. In all patients studied, low EBC pH levels were associated with a decreased diffusing capacity for carbon monoxide (DLCO) during follow-up. Low FeNO levels were correlated with lower forced vital capacity (FVC) at baseline, 4 years of follow-up and with a decrease in FVC and DLCO during monitoring. Among ILD patients, high eCO levels were correlated with lower baseline FVC. In the global cohort, a worse progression-free survival was identified in patients with EBC pH values lower than 7.88 and FeNO levels lower than 10.75ppb (log Rank P=0.03 and P<0.01, respectively). ConclusionsEB and EBC could help to detect patients likely to present a deterioration on lung function during follow up.

Aerobic exercise in polluted urban environments: effects on airway defense mechanisms in young healthy amateur runners

In this study, the effects of aerobic exercise on the upper airways and their defense mechanisms were investigated in athletes. The athletes ran in two different environments: the downtown streets of the city of São Paulo (Street), more polluted, and an urban forest (Forest), less polluted. Thirty-eight young healthy athletes ran for 45 min d−1 randomly during five consecutive days, with an interval of 48 h before changing environment. Clinical parameters and respiratory tract defense markers were evaluated before and after the first run on Mondays (1 d) and on Fridays (5 d). Street presented higher mean PM2.5 concentrations (65.1 ± 39.1 µg m−3, p < 0.001) and lower temperature (22.0 °C, p = 0.010) than Forest (22.6 ± 15.3 µg m−3 and 22.8 °C). After 1 d Street running, subjects showed an increment in heart rate (p < 0.001). At day 5, there was twice the number of athletes with impaired nasal mucociliary clearance (MCC) in the Street runners group when compared to the Forest runners group. Exhaled breath condensate pH values increased in the Forest group, with significant differences between groups in day 1 (p = 0.006) and day 5 (p < 0.001), despite the fact that both groups showed values within the normal range. After exposure to both environments, the number of cells in the nasal lavage fluid was reduced after exercise (p = 0.014), without alterations in cell type and IL-8 and IL-10 concentrations. Aerobic exercise can either maintain or acutely enhance MCC and it may help to regulate inflammatory responses in the airways. Here we show that exercise practice in polluted outdoor environment, over a 5 d period, impairs MCC. In contrast, athletes running in the less polluted environment (Forest) show higher exhaled breath condensate pH values when compared to those who exercised in a more polluted environment (Street).

Living near a Major Road in Beijing: Association with Lower Lung Function, Airway Acidification, and Chronic Cough.

Background:The effects of near-road pollution on lung function in China have not been well studied. We aimed to investigate the effects of long-term exposure to traffic-related air pollution on lung function, airway inflammation, and respiratory symptoms.Methods:We enrolled 1003 residents aged 57.96 ± 8.99 years living in the Shichahai Community in Beijing. Distances between home addresses and the nearest major roads were measured to calculate home-road distance. We used the distance categories 1, 2, and 3, representing <100 m, 100–200 m, and >200 m, respectively, as the dose indicator for traffic-related air pollution exposure. Lung function, exhaled breath condensate (EBC) pH, and interleukin 6 levels were measured. As a follow-up, 398 participants had a second lung function assessment about 3 years later, and lung function decline was also examined as an outcome. We used regression analysis to assess the impacts of home-road distance on lung function and respiratory symptoms. As the EBC biomarker data were not normally distributed, we performed correlation analysis between home-road distance categories and EBC biomarkers.Results:Participants living a shorter distance from major roads had lower percentage of predicted value of forced expiratory volume in 1 s (FEV1% −1.54, 95% confidence interval [CI]: −0.20 to −2.89). The odds ratio for chronic cough was 2.54 (95% CI: 1.57–4.10) for category 1 and 1.97 (95% CI: 1.16–3.37) for category 2, compared with category 3. EBC pH was positively correlated with road distance (rank correlation coefficient of Spearman [rs] = 0.176, P < 0.001).Conclusions:Long-term exposure to traffic-related air pollution in people who live near major roads in Beijing is associated with lower lung function, airway acidification, and a higher prevalence of chronic cough. EBC pH is a potential useful biomarker for evaluating air pollution exposure.

The relationships among Dermatophagoides pteronyssinus exposure, exhaled nitric oxide, and exhaled breath condensate pH levels in atopic asthmatic children

This study examined seasonal changes in indoor Dermatophagoides pteronyssinus 1 (Der p 1)/Blattella germanica 1 (Bla g 1) antigen concentrations in the homes of atopic asthmatic and atopic nonasthmatic children. Possible associations between environmental allergen exposure and levels of exhaled breath indices were also evaluated.A total of 38 atopic children were recruited for this cross-sectional study: 22 were asthmatic and 16 were nonasthmatic. Home visits were conducted for indoor air and dust sampling each season. Exhaled nitric oxide (eNO)/spirometric measurements were taken and exhaled breath condensate (EBC) was collected after sampling of the domestic environment.The highest Der p 1 concentrations were on the top of mattresses in the homes of recruited children. The floors of kitchens and living rooms had the highest Bla g 1 concentrations in the homes of atopic asthmatic children. A positive correlation was found between Der p 1 exposure of mattress, bedroom floor, and living room floor and eNO levels in the atopic asthmatic children. The Der p 1 concentrations on the surfaces of mattress and bedroom floor were positively related to high eNO levels in the atopic asthmatic children after adjusting for season. No association was found between Der p 1 exposure and EBC pH values in the recruited children.A positive correlation was found between Der p 1 exposure and high eNO levels in atopic asthmatic children, especially in Der p 1 exposure of mattress and bedroom floor.

Airway oxidative stress and inflammation markers in chronic obstructive pulmonary diseases(COPD) patients are linked with exposure to traffic-related air pollution: a panel study

To investigate the effects of short-term exposure to traffic-related air pollution on airway oxidative stress and inflammation in chronic obstructive pulmonary diseases (COPD) patients. A panel of forty-five diagnosed COPD patients were recruited and followed with repeated measurements of biomarkers reflecting airway oxidative stress and inflammation in exhaled breath condensate (EBC), including nitrate and nitrite, 8-isoprostane, interleukin-8 and acidity of EBC (pH), between 5(th) September in 2014 and 26(th) May in 2015. The associations between air pollution and biomarkers were analyzed with mixed-effects models, controlling for confounding covariates. The concentration of PM2.5, black carbon, NO2 and number concentration of particles with diameter less than 100 nm (PNC100), and particles in size ranges between 100 nm to 200 nm (PNC100-200) during the first follow-up were (156.5±117.7), (10.7±0.7), (165.9±66.0)μg/m(3) and 397 521±96 712, 79 421±44 090 per cubic meter, respectively; the concentration were (67.9±29.6), (3.4±1.3), (126.1±10.9) μg/m(3) and (295 682±39 430), (24 693±12 369) per cubic meter, respectively during the second follow-up. The differences were of significance, with t value being 3.10, 4.42, 2.61, 4.02, 5.12, respectively and P value being 0.005,<0.001, 0.016, <0.001 and <0.001, respectively. In our COPD-patient panel, per interquartile range (IQR) increase in PNC100-200, we observed an increase of 65% (95% CI: 8%-152%) in nitrate and nitrite in EBC reflecting airway oxidative stress. For an IQR increase in PM2.5, black carbon and PNC100-200, respective increases of 0.17 ng/ml (95% CI: 0.02-0.33), 0.12 ng/ml (95% CI: 0.01-0.24) and 0.13 ng/ml (95% CI:0.02-0.24) in interleukin-8 in EBC reflecting airway inflammation were also observed. An IQR increase in ozone was also associated with a 0.24 (95%CI: 0.05-0.42) decrease in pH of EBC reflecting increased airway inflammation. No significant association observed between air pollution and 8-isoprostane in EBC in COPD patients. Our results suggested that short-term exposure to traffic-related air pollution was responsible for exacerbation of airway oxidative stress and inflammation in COPD patients.

Effect of exercise duration on pro-oxidants and pH in exhaled breath condensate in humans

Exercise promotes pulmonary oxidative imbalance. In this regard, some evidence has been obtained from the study of exhaled breath condensate (EBC) during urban races, in which the factors involved in the occurrence of this process are still not characterized. In this paper, under laboratory conditions, both the role of time of exercise on the generation of pro-oxidants (H2O2, NO2 (-)) and pH have been assessed in EBC of 16 under-trained subjects who completed three tests of cycloergometric exercise at low intensity (30% of VO2 max) with a duration of 10, 30, and 90min. Samples were obtained as follows: immediately before and at 80min post exertion in each test. In the 90-min test, an increase in H2O2, NO2 (-) concentration in EBC at 80min post exertion with no changes in the pH was observed. Total O2 consumption and total ventilation weakly correlated with the changes in H2O2 and NO2 (-). In conclusion, the concentration of pro-oxidants in the EBC depends on the duration of the exercise when it is performed at low intensity under laboratory conditions.

Exhaled breath analysis in childhood rheumatic disorders—a longitudinal study

We aimed to evaluate the fraction of exhaled nitric oxide (FENO50) and deaerated exhaled breath condensate pH (dEBCpH) as non-invasive markers of subclinical airway inflammation in pediatric patients with rheumatologic disorders.We determined FENO50 and dEBCpH in a prospective study spanning at least 12 months, comprising 85 pediatric patients with rheumatologic disorders, including juvenile idiopathic arthritis (JIA, n = 63), chronic recurrent multifocal osteomyelitis (CRMO, n = 6), systemic lupus erythematosus (SLE, n = 3), juvenile dermatomyositis (JDM, n = 1) and other rheumatic disorders (n = 12). dEBCpH was determined once in a group of children without evidence of rheumatologic or pulmonary disease (controls, n = 90). Findings were correlated with results of pulmonary function tests. Atopic sensitization was assessed by RAST or skin prick test in 76 patients.Atopic sensitization was detected in 34% (26/76) of patients. Neither FENO50 nor dEBCpH correlated with disease activity, but intermediately (20–35 ppb) or highly elevated (>35 ppb) levels were observed at least once in 26 patients (31%), 19 of whom had atopic sensitization. Median dEBCpH did not differ between cases and controls (8.05 versus 8.02; p = 0.48). Median dEBCpH decreased slightly over the study period (p = 0.02), whereas FENO50 values did not change significantly (p = 0.89). There were several patients with significantly abnormal dEBCpH values that could not be readily explained by diagnosis, higher disease activity, medications, or atopic sensitization.Thus, there were no consistent abnormalities in FENO50 or dEBCpH in this cohort of Caucasian patients with relatively stable rheumatologic disorders, but there were some patients with abnormal values of unknown significance.