Giovanna E. Carpagnano

Increased inflammatory markers in the exhaled breath condensate of cigarette smokers

Cigarette smoking induces an inflammatory response in the airways that may play a key role in the pathogenesis of chronic obstructive pulmonary disease. Noninvasive markers of inflammation may, therefore, be useful in monitoring the airways of smokers as well as in the screening of subjects at high risk of developing airway obstruction. The aim of the present study was to determine whether the concentrations of the pro-inflammatory cytokine, interleukin (IL)-6, is increased in the exhaled breath condensate of smokers and whether the number of cigarettes smoked has any influence on the exhaled concentrations. The possibility that exhaled IL-6 levels are related to exhaled carbon monoxide (CO) and lung function has also been explored. Another inflammatory marker, leukotriene (LT), was also measured. Twenty-one smokers (39±7 yrs, 13 male) and 14 nonsmokers (45±6 yrs, eight male) were recruited. IL-6 and LTB4 levels in the breath condensate were measured with an immunoassay kit and exhaled CO examined by means of a modified electrochemical sensor. Higher IL-6 and exhaled CO concentrations were found in current smokers (5.6±1.4 pg·mL−1 and 16.7±5.5 parts per million (ppm)) than in nonsmokers (2.6±0.2 pg·mL−1 and 2.1±0.6 ppm). Elevated concentrations of LTB4 were also observed in smokers compared to nonsmokers (9.4±0.4 pg·mL−1 versus 6.1±0.3 pg·mL−1). In addition, there was a correlation between IL-6 concentrations, the number of cigarettes smoked per day, exhaled CO, LTB4 and lung function. Exhaled interleukin-6 and leukotriene B4 levels may be useful noninvasive markers of airway inflammation in cigarette smokers.

Supplementary oxygen in healthy subjects and those with COPD increases oxidative stress and airway inflammation.

Background: Hyperoxia increases oxidative stress through the generation of reactive oxygen species and may therefore enhance inflammation in the lungs. The aim of this study was to investigate whether short term supplementary oxygen (28%) increases oxidative stress and inflammation in the airways by measuring 8-isoprostane and interleukin 6 (IL-6) concentrations in exhaled breath condensate. Methods: Twenty three healthy subjects (12 men, mean (SD) age 48 (7) years) and 23 patients with chronic obstructive pulmonary disease (COPD; 15 men, mean (SD) age 56 (5) years) were studied. 8-isoprostane and IL-6 concentrations were measured by immunoassay. Results: Increased concentrations of 8-isoprostane and IL-6 were found in all subjects after breathing 28% oxygen for 1 hour. In healthy subjects the concentrations of 8-isoprostane and IL-6 were 10.9 (2.9) pg/ml and 4.9 (0.8) pg/ml, respectively, compared with baseline concentrations of 6.1 (1.3) pg/ml and 2.9 (0.6) pg/ml, and in patients with COPD the concentrations were 27.9 (3.1) pg/ml and 8.3 (1.2) pg/ml), respectively, compared with baseline concentrations of 18.9 (3.6) pg/ml and 6.3 (0.6) pg/ml. By contrast, breathing air through the same face mask for 1 hour had no significant effects on 8-isoprostane or IL-6 concentrations in normal subjects or those with COPD. Conclusions: These findings suggest that short term supplementary oxygen may enhance oxidative stress and inflammation in the airways. Whether this happens with long term oxygen therapy needs to be determined.

Gender, age and menopause effects on the prevalence and the characteristics of obstructive sleep apnea in obesity

Background  In the 1970s and 80s it was believed that obstructive sleep apnea (OSA) was primarily a disease of men. The present study was addressed to evaluate the effect of gender and menopause on the prevalence and the characteristics of OSA and on anthropometric, clinical, respiratory and polysomnographic data in a population of obese individuals.

IL-2, TNF-α, and Leptin: Local Versus Systemic Concentrations in NSCLC Patients

One recent line of cancer research shows increasing interest for biological factor such as IL-2, TNF-α, and leptin, which have been found to participate in the development and progression of non-small cell lung cancer (NSCLC). The aim of this study was to measure IL-2, TNF-α, and leptin concentrations in the airways and in the systemic circle of patients with NSCLC, investigating the role of these factors in the lung tumors. We enrolled 32 patients (17 men, 71 ± 7 years) with a histological diagnosis of NSCLC and 20 healthy ex-smoker controls, negative for computed tomography of the chest (14 men, 69 ± 8 years). IL-2, TNF-α, and leptin levels were measured in the serum, the urine, the bronchoalveolar lavage, the induced sputum, and exhaled breath condensate (EBC) of patients enrolled by means of a specific enzyme immunoassay kit. Higher concentrations of IL-2, TNF-α and leptin were found in NSCLC patients than in controls (p < 0.0001). A statistically significant increase of IL-2, TNF-α, and leptin concentrations was observed in patients from stage I to stage III of NSCLC. These findings suggest that IL-2, TNF-α, and the leptin play an important role in the cancerogenesis of NSCLC. Their measure in the EBC could be proposed as noninvasive markers for an early detection of NSCLC and in the follow-up of this tumor.

Endothelin-1 Is Increased in the Breath Condensate of Patients with Non-Small-Cell Lung Cancer

One recent line of cancer research is currently directed to the study of growth factors. Of increasing interest is endothelin-1 (ET-1), a mitogenic factor already investigated in several human cancer cell lines, which has been found to participate in the development and progression of tumours. This peptide has an important role also in non-small-cell lung cancer (NSCLC) where ET-1 expression has been found in 100% of cell lines. Objectives: The aim of this study was to measure ET-1 concentrations in the airways of patients with NSCLC using a completely non-invasive procedure – the breath condensate – and to verify the involvement of this peptide in the growth of lung tumours. Methods: We enrolled 30 patients (17 men, median age 63 years; range 53–74) with histological evidence of NSCLC and 15 healthy controls (9 men, median age 59 years; range 52–70). ET-1 was measured in the exhaled breath condensate by means of a specific enzyme immunoassay kit. Results: Higher concentrations of exhaled ET-1 were found in NSCLC patients (8.3 ± 0.7 pg/ml) compared to controls (5.2 ± 0.5 pg/ml, p < 0.0001). A statistically significant difference was observed between patients with distant metastases (stage IV) of NSCLC (8.9 ± 0.6 pg/ml) and those with locoregional disease (stage I–III) (7.9 ± 0.5 pg/ml). A significant reduction in ET-1 levels was found in 14 patients after surgical removal of the tumour either associated with or without adjuvant chemotherapy (6.3 ± 0.5 vs. 7.9 ± 0.4 pg/ml, p < 0.0001). Conclusions: These findings suggest that the measurement of ET-1 in the breath condensate of patients with NSCLC could be proposed as a marker for early detection of NSCLC as well as for monitoring reduction or progression of the neoplasm in the follow-up of treated patients.

Systemic and airway inflammation in sleep apnea and obesity: the role of ICAM-1 and IL-8

The recurrent hypoxic stress that characterizes obstructive sleep apnea (OSA) seems to play a role in the increased adherence of neutrophils to endothelial cells as well as in the resulting migration of the former to the inflamed area. Intercellular adhesion molecule 1 (ICAM-1) and interleukin (IL)-8 are markers widely used in OSA studies to investigate inflammation. The aim of this study was to measure ICAM-1 and IL-8 levels in the breath condensate and in the plasma and inflammatory cells in the induced sputum of 12 obese OSA (OO) patients, 10 nonobese OSA (NOO) patients, 10 obese non-OSA (ONO) subjects, and 8 healthy subjects (HS) using a specific enzyme immunoassay (EIA) kit. A significant increase in both plasma and exhaled IL-8 and ICAM concentrations and percentage neutrophils was observed in the induced sputum of obese OSA patients, non-obese OSA patients, and obese non-OSA subjects compared with healthy subjects. However, although these inflammatory markers were found to follow an upward trend in obese OSA patients no difference was observed in both either non-obese OSA patients and obese non-OSA subjects. Finally, a significant positive correlation was found to occur among IL-8, ICAM-1, and sputum neutrophils, as well as across the apnea-hypopnoea index (AHI), TST 90%, body mass index (BMI), and neck circumference. The data obtained confirm the occurrence of an ICAM- and IL-8-mediated neutrophilic airway inflammation in both OSA and obese patients. The degree of inflammation, which seems to worsen in cases of comorbidity (OSA and obesity), is likely to be responsible for the increased risk of developing cardiovascular events observed in these subjects, and therefore, it deserves to be elucidated even more.

Interleukin-6 is increased in breath condensate of patients with non-small cell lung cancer.

Despite recent advances in the diagnosis and treatment of non-small cell lung cancer (NSCLC), most patients still present with advanced stage disease at the time of diagnosis. Recent studies suggest that IL-6 is involved in the development of lung cancer. The aim of the present study was to investigate whether the measurement of IL-6 levels in the breath condensate of NSCLC patients could be used to bring forward the moment of diagnosis and to monitor the progression of the disease. Twenty patients with histological evidence of NSCLC (14 men and 6 women, age 63±8 years) and 15 healthy controls (8 men and 7 women, age 45±6 years) were enrolled in the study. IL6 was measured in the exhaled breath condensate of patients and controls by means of a specific enzyme immunoassay kit. Higher concentrations of exhaled IL-6 were found in NSCLC patients (9.6±0.3 pg/mL) than in controls (3.5±0.2 pg/mL). A statistically significant difference was observed between patients with NSCLC at different stages: higher concentrations of IL-6 (10.9±0.5 pg/mL) were found in patients with metastatic disease than in those with stage III (9.7±0.4 pg/mL), stage II (8.9±0.3 pg/mL) and stage I disease (7.9±0.3 pg/mL). These findings suggest that the measurement of IL-6 in the breath condensate of patients with NSCLC could be proposed as a parameter to take into account in early diagnosis and disease monitoring.

A European Respiratory Society technical standard: exhaled biomarkers in lung disease

Breath tests cover the fraction of nitric oxide in expired gas (FENO), volatile organic compounds (VOCs), variables in exhaled breath condensate (EBC) and other measurements. For EBC and for FENO, official recommendations for standardised procedures are more than 10 years old and there is none for exhaled VOCs and particles. The aim of this document is to provide technical standards and recommendations for sample collection and analytic approaches and to highlight future research priorities in the field. For EBC and FENO, new developments and advances in technology have been evaluated in the current document. This report is not intended to provide clinical guidance on disease diagnosis and management. Clinicians and researchers with expertise in exhaled biomarkers were invited to participate. Published studies regarding methodology of breath tests were selected, discussed and evaluated in a consensus-based manner by the Task Force members. Recommendations for standardisation of sampling, analysing and reporting of data and suggestions for research to cover gaps in the evidence have been created and summarised. Application of breath biomarker measurement in a standardised manner will provide comparable results, thereby facilitating the potential use of these biomarkers in clinical practice. ERS technical standard: exhaled biomarkers in lung disease http://ow.ly/mAjr309DBOP

Exhaled NO and iNOS expression in sputum cells of healthy, obese and OSA subjects

Background.  Obstructive sleep apnoea (OSA) is associated with airways inflammation; a key role in this regard seems to be played by nitric oxide (NO). The aim of this study was to measure exhaled NO and expression of its enzyme, the inducible nitric oxide synthase (iNOS) in cells of induced sputum in OSA patients and in obese subjects without sleep apnoea and to correlate these inflammatory markers with severity of OSA.

Airway inflammation in subjects with gastro-oesophageal reflux and gastro-oesophageal reflux-related asthma

Study objectives.  Asthma and gastro‐oesophageal reflux (GER) are both characterized by airway inflammation.