Zsofia Lazar

Established methodological issues in electronic nose research: how far are we from using these instruments in clinical settings of breath analysis?

Electronic noses (e-noses) represent an easy and cheap method for exhaled volatile compound analysis. Various electronic noses are available which differ in material and thus analytical performance. In this review, we describe a wide range of electronic noses and summarize data on the methodological issues in electronic nose research. We also review studies which show the ability of electronic noses to distinguish pulmonary and extrapulmonary disorders from health.

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.

Cigarette smoke attenuates the production of cytokines by human plasmacytoid dendritic cells and enhances the release of IL-8 in response to TLR-9 stimulation

Myeloid and plasmacytoid dendritic cells (mDCs, pDC) are crucial to the immune system, detecting microorganisms and linking the innate and adaptive immunity. pDC are present in small quantities in tissues that are in contact with the external environment; mainly the skin, the inner lining of the nose, lungs, stomach and intestines. They produce large amounts of IFN-α after stimulation and are pivotal for the induction of antiviral responses. Chronic obstructive pulmonary disease (COPD) patients are known to be more susceptible to viral infections. We have demonstrated that exposure of mDC to cigarette smoke extract (CSE) leads to the release of chemokines, however, not much is known about the role of pDC in COPD. In this study, we addressed several key questions with respect to the mechanism of action of CSE on human pDC in an in vitro model. Human pDCs were isolated from normal healthy volunteers and subjected to fresh CSE and the levels of IL-8, TNF-α, IP-10, IL-6, IL-1, IL-12 and IL-10 and IFN-α were studied by both ELISA and real time PCR methods. We observed that CSE augmented the production of IL-8 and suppressed the release of TNF-α, IL-6 and IFN-α. Moreover, CSE suppressed PI3K/Akt signalling in pDC. In conclusion, our data indicate that CSE has both the potential to diminish anti-viral immunity by downregulating the release of IFN-α and other pro-inflammatory cytokines while, at the same time, augmenting the pathogenesis of COPD via an IL-8 induced recruitment of neutrophils.

Ceramide-1-phosphate inhibits cigarette smoke-induced airway inflammation

Sphingolipids are involved in the pathogenesis of inflammatory diseases. The central molecule is ceramide, which can be converted into ceramide-1-phosphate (C1P). Although C1P can exert anti- and pro-inflammatory effects, its influence on cigarette smoke (CS)-induced lung inflammation is unknown. We aimed to clarify the role of C1P in the pathogenesis of CS-triggered pulmonary inflammation and emphysema in humans and mice. The effects of C1P were addressed on CS-induced lung inflammation in C57BL/6 mice, CS extract-triggered activation of human airway epithelial cells (AECs) and neutrophils from patients with chronic obstructive pulmonary disease. Differential cell counts in bronchoalveolar lavage fluid were determined by flow cytometry and pro-inflammatory cytokines were measured by ELISA. Expression and DNA binding of nuclear factor (NF)-κB and neutral sphingomyelinase (nSMase) were quantified by PCR, electrophoretic mobility shift and fluorometric assays. C1P reduced CS-induced acute and chronic lung inflammation and development of emphysema in mice, which was associated with a reduction in nSMase and NF-κB activity in the lungs. nSMase activity in human serum correlated negatively with forced expiratory volume in 1 s % predicted. In human AECs and neutrophils, C1P inhibited CS-induced activation of NF-κB and nSMase, and reduced pro-inflammatory cytokine release. Our results suggest that C1P is a potential target for anti-inflammatory treatment in CS-induced lung inflammation. Ceramide-1-phosphate, a potential target for anti-inflammatory treatment in cigarette smoke-induced lung inflammation http://ow.ly/E7tUS

Exhaled biomarker pattern is altered in children with obstructive sleep apnoea syndrome

OBJECTIVES Obstructive sleep apnoea syndrome (OSAS) is a common disorder in children, which is associated with enhanced inflammatory status. Inflammation-associated changes could be monitored by the assessment of exhaled biomarker profile. This study aimed to compare the exhaled biomarker profile in children with OSAS and habitual snorers. METHODS Eighteen children with OSAS (8 ± 2 years, mean ± SD) and ten non-OSAS subjects with habitual snoring (9 ± 2 years) were recruited. Exhaled breath was collected from the lower airways, processed using an electronic nose (E-nose) and analyzed off-line using principal component analysis, followed by discrimination analysis and logistic regression to build a receiver operating characteristic (ROC) curve. RESULTS Exhaled biomarker pattern of OSAS patients was discriminated from that of control subjects (p = 0.03, cross-validation accuracy: 64%), ROC curve analysis (area: 0.83) showed 78% sensitivity and 70% specificity. CONCLUSIONS The altered exhaled biomarker pattern in OSAS might reflect accelerated airway and/or systemic inflammation in diseased state. Breath pattern analysis by an E-nose can serve as a new tool to monitor inflammation in children with OSAS.

Exercise increases exhaled breath condensate cysteinyl leukotriene concentration in asthmatic patients

Background. Although the importance of cysteinyl leukotrienes (Cys-LTs) in exercise-induced bronchoconstriction (EIB) is supported by various sources of evidence, how the concentration of these mediators change during the development of EIB has not been investigated. Objectives. Our goal was to determine the effect of exercise on the concentration of airway Cys-LT in asthmatic patients by measuring Cys-LT in exhaled breath condensate (EBC). Methods. Seventeen atopic asthmatic patients with a previous history of EIB and six healthy volunteers were studied. Before and two times within 10 minutes after exercise challenge, FEV1 was measured and EBC was collected for Cys-LT measurement. Exhaled nitric oxide level, a marker of airway inflammation, was also determined at baseline. Results. Baseline Cys-LT level was higher in the asthmatic group versus healthy subjects (168 pg/mL /112–223/ vs. 77 pg/mL /36–119/, p = .03). EBC Cys-LT concentration increased in all asthmatic patients post-exercise (n = 17, p = .03), with the increase significantly greater in patients developing exercise-induced bronchospasm (n = 7, p = .03), whereas no change was observed in healthy controls (p = .59). The exercise-induced fall in FEV1 in asthmatics was related to the increase in EBC Cys-LT concentration (r = −0.40, p = .03). Conclusions. Our study shows that Cys-LT concentration of EBC is elevated minutes after physical exercise in asthmatic patients and strongly supports the concept that the release of this mediator is involved in the development of EIB.

Exhaled breath volatile alterations in pregnancy assessed with electronic nose

Context: Pregnancy-linked accelerated metabolism and oxidative stress may alter the exhaled volatile compound pattern (“breathprint”). Electronic noses can distinguish “breathprints” associated with different disorders. Objective: This is the first study assessing alterations in “breathprint” during gestation. Material and methods: 130 women participated in our study (78 pregnant vs. 52 non-pregnant). Breath samples were processed by an electronic nose and analyzed using principal component analysis. Results: Significant differences were found in exhaled breath pattern between pregnant and non-pregnant women (p = 0.001). Conclusion: Pregnancy-induced changes in exhaled gases need to be considered when pregnant women with respiratory disorders carry out breath tests.

Exhaled breath condensate pH is influenced by respiratory droplet dilution

Several studies support that airway acid stress plays a role in the pathophysiology of asthma. Exhaled breath condensate pH (EBC pH) was suggested as a surrogate marker of airway acidification. The dilution of airway lining fluid (ALF) acids and bases by alveolar water may influence condensate pH, but it has not been studied yet. The aim of our study was to investigate the relationship between EBC pH and ALF dilution in EBC samples obtained from asthmatic and healthy subjects. EBC was collected from 55 asthmatic and 57 healthy subjects for pH and conductivity measurements. Fractional exhaled nitric oxide (FE(NO)) and lung function tests were also performed in asthmatic patients. EBC pH was determined after 10 min of argon deareation and the dilution was estimated by the measurement of conductivity in vacuum-treated samples. There was no difference either in EBC pH or dilution between the two groups. However, a significant relationship was found between EBC pH and dilution in both groups (p < 0.05, r = -0.35 and r = -0.29, asthmatic and healthy groups, respectively). Our results suggest important methodological aspect indicating that EBC pH is affected by respiratory droplet dilution, and this effect should be taken into consideration when interpreting EBC pH data.

Altered purinergic signaling in the tumor associated immunologic microenvironment in metastasized non-small-cell lung cancer.

OBJECTIVES Purines are well-known as intracellular sources for energy but they also act as extracellular signaling molecules. In the recent years, there has been a growing interest in the therapeutic potential of purinergic signaling for cancer treatment. This is the first study to analyze lung purine levels and purinergic receptors in non-small-cell lung cancer (NSCLC) patients. MATERIALS AND METHODS In this prospective clinical trial we enrolled 26 patients with NSCLC and 21 patients with chronic obstructive pulmonary disease (COPD) without signs of malignancy. The purine concentrations were analyzed in bronchoalveolar lavage fluid (BALF) using fluorescent/luminescent assays. Expression of purinergic receptors and ectonucleotidases were analyzed using real time quantitative polymerase chain reaction (RT-qPCR). RESULTS Patients with NSCLC have significantly lower ATP and ADP concentrations in BALF than patients with COPD (p=0.006 and p=0.009). Expression of the ectonucleotidase CD39 is significantly higher in BAL cells from cancer patients compared to COPD (p=0.001) as well as in metastasized tumors compared to non-metastasized tumors (p=0.009). Receptor-analysis revealed a higher expression of P2X4 (p=0.03), P2X7 (p=0.001) and P2Y1 (p=0.003) in BAL cells of tumors with distant metastasis. CONCLUSION Our data suggests a role for CD39 in lung cancer tumor microenvironment, influencing tumor invasiveness and metastasization. Potentially the increased degradation of ATP and ADP leads to a subversion of their anti-neoplastic effects. Furthermore P2Y1, P2X4 and P2X7 receptors are upregulated in BAL cells in metastatic disease. Our findings might facilitate the identification of new therapeutic targets for cancer immunotherapy.

Genetic influence on the relation between exhaled nitric oxide and pulse wave reflection.

Nitric oxide has an important role in the development of the structure and function of the airways and vessel walls. Fractional exhaled nitric oxide (FE(NO)) is inversely related to the markers and risk factors of atherosclerosis. We aimed to estimate the relative contribution of genes and shared and non-shared environmental influences to variations and covariation of FE(NO) levels and the marker of elasticity function of arteries. Adult Caucasian twin pairs (n = 117) were recruited in Hungary, Italy and in the United States (83 monozygotic and 34 dizygotic pairs; age: 48 ± 16 SD years). FE(NO) was measured by an electrochemical sensor-based device. Pulse wave reflection (aortic augmentation index, Aix(ao)) was determined by an oscillometric method (Arteriograph). A bivariate Cholesky decomposition model was applied to investigate whether the heritabilities of FE(NO) and Aix(ao) were linked. Genetic effects accounted for 58% (95% confidence interval (CI): 42%, 71%) of the variation in FE(NO) with the remaining 42% (95%CI: 29%, 58%) due to non-shared environmental influences. A modest negative correlation was observed between FE(NO) and Aix(ao) (r = -0.17; 95%CI:-0.32,-0.02). FE(NO) showed a significant negative genetic correlation with Aix(ao) (r(g) = -0.25; 95%CI:-0.46,-0.02). Thus in humans, variations in FE(NO) are explained both by genetic and non-shared environmental effects. Covariance between FE(NO) and Aix(ao) is explained entirely by shared genetic factors. This is consistent with an overlap among the sets of genes involved in the expression of these phenotypes and provides a basis for further genetic studies on cardiovascular and respiratory diseases.