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Bikov A.,Semmelweis University | Galffy G.,Semmelweis University | Tamasi L.,Semmelweis University | Bartusek D.,Semmelweis University | And 3 more authors.

Background and objective Exercise-induced bronchoconstriction (EIB) is the temporary narrowing of the airways caused by physical exercise. Its exact pathophysiology is unclear; however, acute changes in airways pH may play a role. Exhaled breath condensate (EBC) pH was suggested as a surrogate indicator for airway acid-base status, but its value is also affected by volatile molecules and respiratory droplet dilution. The aim of the study was to assess changes in EBC pH during EIB. Methods Twenty-two asthmatics who reported breathlessness following exercise and 16 healthy individuals participated in the study. Lung function test was performed and exhaled breath samples were collected for pH, dilution factor and volatile compound pattern measurements (Cyranose 320) pre-exercise and at 0, 10, 20 and 30 min after physical exercise challenge. Fractional exhaled nitric oxide was measured before exercise. Results EIB developed in 13 asthmatic subjects. In these participants, but not in the EIB-negative asthmatics (P = 0.51), EBC pH reduced significantly during exercise (P = 0.01). In addition, changes in EBC pH were related to the degree of bronchospasm in the EIB-positive group (P = 0.01, r = 0.68). Exhaled volatile pattern became altered (P < 0.05) during exercise in all subjects (asthmatics and controls). EBC pH changes were not related to EBC dilution or volatile compound pattern alterations (P > 0.05). Conclusions The development of EIB was related to acute changes of EBC pH, which suggest the role of airway pH decrease in the pathophysiology of EIB. Exercise-induced changes in exhaled biomarkers suggest methodological precautions to avoid physical exercise before performing exhaled breath tests. © 2014 Asian Pacific Society of Respirology. Source

Antus B.,National Koranyi Institute of TB and Pulmonology | Kardos Z.,National Koranyi Institute of TB and Pulmonology
Current Medicinal Chemistry

Chronic obstructive pulmonary disease (COPD) is a major and rapidly increasing health problem associated with a chronic inflammatory response, predominantly in small airways and lung parenchyma. Oxidative stress induced by reactive oxygen and nitrogen species (ROS and RNS) plays a central role in the pathophysiology of COPD. There is evidence that several molecules formed during oxidative processes may have the potential to serve as biomarkers of oxidative stress in the airways of patients with COPD. Among these molecules carbon monoxide, ethane and pentane can be measured in the exhaled air, while 8-isoprostane, malondialdehyde, 4-hydroxyhexenal, 4-hyroxynonenal, acrolein, hydrogen peroxide, nitrogen oxides and 3-nitrotyrosine can be detected in exhaled breath condensate and/or sputum supernatant. In this review the molecular background of these processes including the formation of ROS and RNS, the biosynthesis of essential ω-3 and ω-6 polyunsaturated fatty acids as building blocks of lipids in the cellular membranes and their enzymatic and non-enzymatic metabolism to eicosanoids and related compounds have been summarized. Moreover, the formation of oxidative stress markers studied most commonly in the context of COPD has been briefly discussed. The associations between biomarkers and clinical variables have also been highlighted in an attempt to illustrate the potential clinical applicability of these biomarker measurements. © 2015 Bentham Science Publishers. Source

Antus B.,National Koranyi Institute of TB and Pulmonology
Oxidative Medicine and Cellular Longevity

Although oxidative stress is thought to play a pivotal role in the pathogenesis of inflammatory airway diseases, its assessment in clinical practice remains elusive. In recent years, it has been conceptualized that oxidative stress markers in sputum should be employed to monitor oxidative processes in patients with asthma, chronic obstructive pulmonary disease (COPD), or cystic fibrosis (CF). In this review, the use of sputum-based oxidative markers was explored and potential clinical applications were considered. Among lipid peroxidation-derived products, 8-isoprostane and malondialdehyde have been the most frequently investigated, while nitrosothiols and nitrotyrosine may serve as markers of nitrosative stress. Several studies have showed higher levels of these products in patients with asthma, COPD, or CF compared to healthy subjects. Marker concentrations could be further increased during exacerbations and decreased along with recovery of these diseases. Measurement of oxidized guanine species and antioxidant enzymes in the sputum could be other approaches for assessing oxidative stress in pulmonary patients. Collectively, even though there are promising findings in this field, further clinical studies using more established detection techniques are needed to clearly show the benefit of these measurements in the follow-up of patients with inflammatory airway diseases. © 2016 Balazs Antus. Source

Antus B.,National Koranyi Institute of TB and Pulmonology | Barta I.,National Koranyi Institute of TB and Pulmonology
Lung Cancer

Assessment of exhaled breath condensate (EBC) pH is a promising method for investigating and monitoring airway pathology in a number of lung diseases. In this cross-sectional study we tested whether development of lung cancer is associated with acidification of EBC. EBC was collected in 43 smoking patients with lung cancer (squamous cell carcinoma: 17 patients, adenocarcinoma: 16 patients, and small cell lung cancer: 10 patients) before receiving any anticancer treatment and in 20 healthy smokers without any clinical and radiological evidence of pulmonary tumor. EBC pH was measured by CO 2 gas standardization, the most reliable and accurate method at present. EBC pH in patients with pulmonary tumor (6.68±0.02) and in controls (6.63±0.05) was similar (p>0.05). Results were affected neither by the histological subtype nor the stage of the tumors. Our data suggest that assessment of EBC pH is of limited value for the diagnosis and/or screening of lung cancer. © 2011 Elsevier Ireland Ltd. Source

Antus B.,National Koranyi Institute of TB and Pulmonology | Barta I.,National Koranyi Institute of TB and Pulmonology
Acta Physiologica Hungarica

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. Source

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