Imre Barta

Influence of condensing equipment and temperature on exhaled breath condensate pH, total protein and leukotriene concentrations

BACKGROUND Exhaled breath condensate analysis is an attractive but still not fully standardised method for investigating airway pathology. Adherence of biomarkers to various condensing surfaces and changes in condensing temperature has been considered to be responsible for the variability of the results. Our aims were to compare the efficacy of different types of condensers and to test the influence of condensing temperature on condensate composition. METHODS Breath condensates from 12 healthy persons were collected in two settings: (1) by using three condensers of different type (EcoScreen, R-Tube, Anacon) and (2) by using R-Tube condenser either cooled to -20 or -70 degrees C. Condensate pH at standardised CO(2) level was determined; protein content was measured by the Bradford method and leukotrienes by EIA. RESULTS Breath condensates collected using EcoScreen were more alkaline (6.45+/-0.20 vs. 6.19+/-0.23, p<0.05 and 6.10+/-0.26, p<0.001) and contained more protein (3.89+/-2.03 vs. 2.65+/-1.98, n.s. and 1.88+/-1.99 microg/ml, p<0.004) as compared to the other devices. Only parameters obtained with R-Tube and Anacon correlated. Condensing temperature affected condensate pH (5.99+/-0.20 at -20 degrees C and 5.82+/-0.07 at -70 degrees C, p<0.05) but not protein content. Leukotriene B(4) was not found in any sample and cysteinyl-leukotriene was not found in condensates collected with R-Tube or Anacon. CONCLUSION Condenser type influences sample pH, total protein content and cysteinyl-leukotriene concentration. Condensing temperature influences condensate pH but not total protein content. These results suggest that adherence of the biomarkers to condenser surface and condensing temperature may play a role but does not fully explain the variability of EBC biomarker levels.

Assessment of exhaled breath condensate ph in exacerbations of asthma and chronic obstructive pulmonary disease: A longitudinal study

RATIONALE Exhaled breath condensate pH has been proposed as a noninvasive marker of airway inflammation. However, due to standardization difficulties in pH measurement techniques, different pH readings were obtained in previous studies. OBJECTIVES In this longitudinal study we assessed condensate pH in patients with an exacerbation of asthma or chronic obstructive airway disease using the very precise carbon dioxide standardization method that negates the effect of this gas on condensate acidity. METHODS Condensate pH, fractional exhaled nitric oxide, lung function, and blood gases were measured in 20 nonsmoking patients with asthma and 21 smoking and 17 ex-smoking patients with chronic obstructive airway disease first at hospital admission due to an acute exacerbation of the disease and again at discharge after treatment. Condensate pH was also assessed in 18 smoking and 18 nonsmoking healthy control subjects. MEASUREMENTS AND MAIN RESULTS In patients with asthma, condensate pH was significantly decreased at the time of exacerbation compared with nonsmoking control subjects and increased with treatment. In patients with chronic obstructive airway disease, condensate pH remained unchanged during exacerbation, both in smokers and ex-smokers. Nevertheless, condensates collected from smokers were more acidic than those of ex-smokers. A similar difference was observed between smoker and nonsmoker healthy control subjects. No correlations were found between condensate pH and fractional exhaled nitric oxide or lung function variables measured either at admission or discharge. CONCLUSIONS Our data suggest that exacerbation of asthma, but not chronic obstructive airway disease, is associated with acidification of breath condensate.

Relationship between exhaled nitric oxide and treatment response in COPD patients with exacerbations

Background and objective:  Fractional exhaled nitric oxide (FENO) has been implicated as a pulmonary biomarker in various respiratory diseases, including COPD. In this longitudinal study, the benefit of measuring FENO in a routine clinical setting was assessed in COPD patients hospitalized with an exacerbation of the disease.

Assessment of exhaled nitric oxide by a new hand-held device

BACKGROUND Fractional exhaled nitric oxide (FENO) has been implicated as a pulmonary biomarker. The aim of this study was to compare the performance of a new hand-held device to a standard chemiluminescence analyzer and to another portable device. METHODS FENO levels measured by NObreath (Bedfont) were compared to those of (1) a chemiluminescence detector (Logan, Logan Research) and (2) the electrochemical portable NIOX MINO (Aerocrine) in 18 healthy volunteers on three consecutive occasions: in the morning, 1 h and 24 h later. RESULTS Comparing FENO levels obtained by NObreath to those by Logan values were similar and a very close linear relationship was found between the two devices (r = 0.923, p < 0.001). The mean inter-device difference in FENO level was -3.45 ppb and the limits of agreement (Bland-Altman test) were -10.98 and 4.08 ppb. In the second series FENO levels obtained by NObreath were found to be slightly higher compared to those of NIOX MINO, but still showed a close correlation (r = 0.681, p < 0.001). The mean inter-device difference in FENO level was 4.36 ppb and the limits of agreement were -7.38 and 16.1 ppb. Analyzing the repeated FENO measurements, the mean coefficient of variation using NObreath tended to be lower than that of NIOX MINO (16.9 vs. 24.7%, p = 0.059), while it was similar as the value obtained with Logan (11.8 vs. 9.0%, p = 0.342). CONCLUSIONS FENO values measured with NObreath are reproducible and in good agreement with those obtained by NIOX MINO and Logan indicating that NObreath is suitable for use in clinical practice.

Differential Cytokine Pattern in the Exhaled Breath of Patients with Lung Cancer

Tumour cells may alter the protein pattern of biological samples resulting in specific differences that may aid diagnosis and treatment. In this pilot study we tested the cytokine pattern of exhaled breath condensate of patients with lung cancer. Breath condensates collected from 50 smoking patients with lung cancer and 25 smokers without clinical or radiological sign of a pulmonary tumour but having co-morbidities with similar severity as those with lung cancer were pooled for antibody microarray analysis testing 120 cytokines in parallel. Every cytokine on the array gave a signal in both groups. Nine cytokines including eotaxin, FGFs, IL-10 and MIP-3 were present with more than two-fold difference between the two groups. Large number of cytokines is present in the exhaled breath. Further analysis of specific differences associated with lung cancer may have clinical importance.

Exhaled breath condensate pH in lung transplant recipients with bronchiolitis obliterans syndrome.

Background. Assessment of exhaled breath condensate (EBC) pH is a promising method for investigating airway pathology. However, inaccurate measurement techniques may bias pH readings. In this longitudinal study, we tested whether development of bronchiolitis obliterans syndrome (BOS) in lung transplant recipients is associated with acidification of EBC. Methods. EBC was collected in 15 patients with BOS and 16 stable BOS-free patients during routine clinical visits. From nine BOS patients, samples were collected before and after the onset of BOS, as well. Twenty healthy nontransplant subjects served as controls. EBC pH was measured by the carbon dioxide gas standardization method. Results. EBC pH in patients with and without BOS and controls was similar (BOS group: 6.40±0.04, BOS-free group: 6.45±0.03; controls: 6.39±0.02; P>0.05). In patients who developed BOS during the follow-up, EBC pH before and after the onset of BOS was comparable (pre-BOS: 6.41±0.04 vs. post-BOS: 6.41±0.04; P>0.05). Coefficient of variation for repeated pH measurements in controls and subjects with and without BOS was 2.3%±0.3%, 2.0%±0.3%, and 1.7%±0.2%, respectively (P>0.05). Similarly, the limits of agreement for between-visit variability determined by the Bland-Altman test were comparable among the study groups. Conclusions. These data suggest that assessment of EBC pH is of limited value for the diagnosis of BOS.

Analysis of cytokine pattern in exhaled breath condensate of lung transplant recipients with bronchiolitis obliterans syndrome

IntroductionExhaled breath condensate (EBC) analysis is a promising method for investigating airway pathology. In this pilot study we tested the cytokine pattern of EBC of lung transplant patients with and without clinical evidence of bronchiolitis obliterans syndrome (BOS).Materials and methods Breath condensates collected from eight BOS patients and eight stable BOS-free lung transplant recipients in three consecutive visits were pooled in order to increase protein concentration and were then used for antibody microarray analysis detecting 120 cytokines simultaneously.ResultsNine cytokines exhibited more than twofold increase and four exhibited more than twofold decrease in BOS patients as compared to stable subjects. ConclusionWe conclude that inflammatory cytokines are present in EBC of lung transplant recipients, however the potential benefit of detecting the EBC proteome warrants further studies.

Analysis of cytokine pattern in exhaled breath condensate of patients with squamous cell lung carcinoma.

Exhaled breath condensate (EBC) analysis is a promising method for investigating airway pathology. In this study we compared the cytokine pattern of EBC of patients suffering from squamous cell lung carcinoma with that of healthy smokers. Breath condensates collected from 8 smoking lung cancer patients before receiving any anticancer treatment and 8 smokers without any clinical or radiological evidence of pulmonary tumors were used for antibody microarray analysis testing 120 cytokines simultaneously. Ninety-eight cytokines on the array gave a detectable signal in both groups. Cytokine levels were similar across the samples, and none of the cytokines exhibited a significant increase or decrease in cancer patients as compared to healthy subjects with similar smoking status, lung function, and airway inflammation. The results of this pilot study suggest that patients with squamous cell lung carcinoma cannot be distinguished from smokers with no pulmonary tumors based on EBC cytokine signals only.

Relationship between exhaled nitric oxide and the frequency of severe acute exacerbation of COPD: 3-year follow-up

In a recent trial we have assessed fractional exhaled nitric oxide (FENO) in a cohort of patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD). In the current study we have retrospectively investigated the frequency of severe hospitalization-associated exacerbations in the same cohort over 3 years after the initial FENO measurement. A total of 58 COPD patients were enrolled and allocated either into the low (< 27 ppb) or the high (≥ 27 ppb) FENO group depending on their FENO level at exacerbation. Beside the annual rate of exacerbations, sputum culture results and the frequency of antibiotic treatments were also analyzed during the follow-up. Both the number of exacerbations per patient-year and the hospitalization days due to exacerbations were significantly increased in patients from the low FENO group compared to those from the high FENO group. Sputum samples derived from patients in the low FENO group were more frequently indicative of a bacterial infection compared to those obtained from the other subgroup. Also, the frequency of antibiotic treatments was significantly increased in subjects from the low FENO group. Results of this pilot study suggest that COPD patients have diverse risks for future exacerbations depending on their FENO levels at exacerbation.

Severe asthma database in Hungary, initial steps

Background Patients with severe asthma represent a significant unmet clinical need, however the evidence base for the management of these patients is small. Published literature on prevalence of severe asthma is quite heterogeneous and we do not have accurate data in Hungary. In 2010 we started to build up a severe asthma database involving patients who were treated in the pulmonary care network in Hungary and met the ATS criteria for severe asthma. The aims were to determine severe asthma prevalence and to define and characterize clinical phenotypes further. Methods The survey was carried out by using a special severe asthma questionnaire regarding information of sex, age, disease onset and duration, lung function, atopy, smoking habits, systemic steroid claim, exacerbations. To date 454 patients were recruited. 354 of them were registered by the pulmonary clinics over the country (group 1) while the remainders (n=100) were registered by the asthma outpatient clinic of our institute (group 2). The latter group was operated as a reference group to verify the reliability of questionnaire data received from other centers. Identification of severe asthma phenotypes was started in patients of group 2, and it is based on more detailed clinical features and determination of pattern of airway inflammation using induced sputum, exhaled breath condensate sample analysis and measurement of exhaled NO. Results There were no differences between the two groups in gender distribution, prevalence of atopy, systemic steroid dependency and the mean value of personal best FEV1. On the other hand the mean age of the group 1 was significantly higher, with no difference in asthma duration between the two groups. Considering that the significant indicators of the two groups proved to be quite homogeneous, the combined clinical data of 454 patients were compared to the data published in the literature (ENFUMOSA, SARP, TENOR studies) and no relevant differences were found. Phenotypes of severe asthma with early onset atopic disease, severe asthma with salicylat intolerance and systemic steroid dependency and severe asthma induced by airway infection and characterized by mixed eosinophilicneutrophilic airway inflammation and systemic steroid dependency were found. Conclusion