A case of imported Middle East Respiratory Syndrome coronavirus infection and public health response, Greece, April 2014

On 18 April 2014, a case of Middle East Respiratory Syndrome coronavirus (MERS-CoV) infection was laboratory confirmed in Athens, Greece in a patient returning from Jeddah, Saudi Arabia. Main symptoms upon initial presentation were protracted fever and diarrhoea, during hospitalisation he developed bilateral pneumonia and his condition worsened. During 14 days prior to onset of illness, he had extensive contact with the healthcare environment in Jeddah. Contact tracing revealed 73 contacts, no secondary cases had occurred by 22 April.

Levels of prostaglandin E(2) and Cysteinyl-leukotrienes in sputum supernatant of patients with asthma: the effect of smoking

BACKGROUND

Smoking is associated with worse asthma outcomes and may modify airway inflammation. Such modification may be mediated through an effect on prostaglandin E(2) (PGE(2)) and cysteinyl leukotrienes (Cyst-LTs).

OBJECTIVE

We aimed to determine the levels of both PGE(2) and Cyst-LTs in sputum supernatants of patients with asthma and to investigate the effect of smoking habit as well as their associations with inflammatory cells, bronchial hyperresponsiveness (BHR) and lung function.

METHODS

Ninety-eight patients to asthma (47 smokers) and 40 healthy subjects (20 smokers) were studied. All subjects underwent sputum induction for cell count identification, PGE(2) and Cyst-LTs levels measurement in supernatants, pulmonary function tests and BHR to methacholine.

RESULTS

Patients with asthma had significantly higher levels of both Cyst-LTs and PGE(2) in sputum supernatants compared to healthy subjects [median (interquartile ranges) 432 (287, 575) vs. 91.5 (73.5, 111) pg/mL and 654 (456,789) vs. 117.5 (92,157) pg/mL, respectively, P < 0.001 for both comparisons]. Smoking asthmatics had significantly higher Cyst-LTs and PGE(2) levels compared to non-smoking asthmatics. Cyst-LTs levels in sputum supernatant of smoking asthmatics presented a significant positive association with sputum eosinophils, while PGE(2) levels were positively associated with sputum neutrophils.

CONCLUSIONS

The increased concentrations of PGE(2) and Cyst-LTs in sputum supernatants of smoking asthma are consistent with an up-regulation of these two mediators in this specific phenotype of asthma. Furthermore, Cyst-LTs are associated with eosinophilic inflammation, while PGE(2) is associated with the presence of neutrophilic inflammation in smoking asthma.

Serum angiopoietin-2 and CRP levels during COPD exacerbations

BACKGROUND AND OBJECTIVE

Angiopoietin-2 (Ang-2) is an important mediator of angiogenesis and has been implicated in many inflammatory diseases. COPD is characterized by systemic inflammation, which is enhanced during exacerbations and may be assessed by measuring serum C-reactive protein (CRP). The aim of the study was to evaluate serum CRP and Ang-2 levels on the first (D1) and seventh day (D7) of hospitalization due to a COPD exacerbation and to examine possible associations of CRP and Ang-2 levels and kinetics with the length of hospital stay and outcome.

METHODS

We conducted a prospective study and evaluated 90 patients admitted to the hospital with a diagnosis of an acute exacerbation of COPD. A venous blood sample was obtained from all patients on D1 and D7 of hospitalization, for the measurement of Ang-2 and CRP.

RESULTS

Serum Ang-2 levels were significantly higher on D1 compared to D7 during the course of COPD exacerbation (p < 0.001). Serum CRP levels were also significantly higher on D1 compared to D7 (p < 0.001). Serum Ang-2 presented a significant positive correlation with CRP levels both on D1 and D7 (r = 0.315 and r = 0.228, respectively). Patients with unfavorable outcome had significantly higher Ang-2 levels both on D1 (p = 0.04) and D7 (p = 0.01).

CONCLUSIONS

Serum Ang-2 levels are elevated at the onset of COPD exacerbations and are positively associated with CRP levels. Ang-2 levels decrease during the course of COPD exacerbations in patients with favorable outcome. Serum Ang-2 may serve as a biomarker that could predict the outcome of a COPD exacerbation.

Systemic biomarkers in the evaluation and management of COPD patients: are we getting closer to clinical application?

Chronic obstructive pulmonary disease (COPD) is a complex, multicomponent disease at the clinical, cellular, and molecular levels. Over the past few years there has been a growing interest in the field of biomarkers in COPD and a large number of studies have evaluated potential candidate molecules in different patient settings. Data on systemic biomarkers from large cohorts, including the well-characterized population of the ECLIPSE study, are now available and provide exciting information on the association of biomarkers with clinically important outcomes, including exacerbations, hospitalizations and mortality. Moreover, recent research has provided proof for the existence of distinct "systemic inflammatory" phenotypes. This review summarizes the currently available evidence on systemic biomarkers in COPD, providing clinically relevant information on the possible role of systemic biomarkers in the evaluation of disease activity and severity, phenotypes, outcomes, COPD exacerbations and treatment response and guidance. Despite the fact that no single biomarker is currently ready to characterize sufficiently the status of COPD patients, guide treatment options, and predict future events, recent studies have rendered our current knowledge definitely more advanced than a few years ago and the possible use of biomarkers in the diagnosis and management of COPD patients looks even more promising.

Vascular endothelial growth factor and cysteinyl leukotrienes in sputum supernatant of patients with asthma

BACKGROUND

Vascular endothelial growth factor (VEGF) is considered to be the most important angiogenic factor in asthma. Cysteinyl leukotrienes (Cyst-LTs) have been implicated in vascular permeability in asthma. Cyst-LTs receptor antagonists modulate vascular permeability by reducing VEGF expression.

OBJECTIVE

We aimed to determine the levels of VEGF and Cyst-LTs in sputum supernatants of patients with asthma and to investigate possible associations within them and with airway vascular permeability (AVP) index. Possible confounding factors were also assessed.

METHODS

One hundred twenty one patients with asthma (38 with severe refractory asthma, 41 smokers) and 30 healthy subjects (15 smokers) were studied. All subjects underwent lung function tests, and sputum induction for cell count identification and VEGF, Cyst-LTs, measurement in supernatants. AVP index was also assessed.

RESULTS

Both VEGF & Cyst-LTs (pg/ml) levels were significantly elevated in patients with asthma compared to normal subjects (median, interquartile ranges 845 [487-1034] vs. 432 (327-654) and 209 [171-296] vs. 92 [75-114] respectively, p < 0.001 for both). Multivariate regression analysis in the whole group showed a significant association of Cyst-LTs levels in sputum supernatants with VEGF levels in sputum supernatants and AVP index. A similar positive association was observed between VEGF levels in sputum supernatants and AVP index. The presence of Severe asthma was a significant covariate for both associations.

CONCLUSION

Our results indicate that Cyst-LTs may modulate vascular permeability by up-regulating VEGF expression. The above effect seems to be affected by asthma severity.

Depression, physical activity, energy consumption, and quality of life in OSA patients before and after CPAP treatment

BACKGROUND

A variety of studies have demonstrated improvement in quality of life and depressive symptoms in obstructive sleep apnea (OSA) patients after continuous positive airway pressure (CPAP) treatment. However, very little is known about the effect of OSA treatment on physical activity and energy consumption.

OBJECTIVES

The aim of this study was to evaluate the changes in depression, physical activity, energy expenditure, and quality of life (QoL) in OSA patients before and after CPAP therapy.

METHODS

Forty-one patients with OSA as revealed by polysomnography, were included to the study. They responded to the generic World Health Organization Quality of Life (WHOQoL) questionnaire, to the specific-disease Quebec Sleep Questionnaire, and to Center for Epidemiologic Studies Depression Scale (CES-D) in order to evaluate QoL and the incidence of depression. In addition, all patients wore an accelerometer which measured physical activity and energy expenditure during a week. At least 6 months after initiation of CPAP treatment (mean time, 9 months) we re-examined 24 patients who met the compliance with the treatment criteria.

RESULTS

Patients after CPAP therapy had significantly higher scores in all domains of the Quebec Sleep Questionnaire and in the domains of physical health/level of independence and psychological health/spirituality of the WHOQoL. Depression scores were also better in CES-D after treatment. However, despite the improvement in QoL and psychological status, CPAP therapy had no impact on physical activity and energy expenditure.

CONCLUSIONS

CPAP therapy improves QoL and lessens depressive symptoms in our group of well-treated OSA patients. However, physical activity and energy expenditure did not present statistically significant improvement in the same group of OSA patients.

Associations between BODE index and systemic inflammatory biomarkers in COPD

BACKGROUND

COPD is a multicomponent disease and systemic inflammation represents one of the possible mechanisms responsible for its systemic manifestations, including skeletal muscle weakness and cachexia. Fat-free mass index (FFMI) that reflects the skeletal muscle mass, has been shown to be associated with both dyspnoea and exercise capacity. We hypothesized that the multidimensional BODE index, that reflects the multicomponent nature of COPD, might be related to biomarkers of systemic inflammation. We further evaluated associations between FFMI and systemic inflammation.

METHODS

BODE index and FFMI were calculated in 222 stable COPD patients and 132 smokers or ex-smokers with normal lung function. Systemic inflammation was evaluated with the measurement of leptin, adiponectin, CRP, IL-6, and TNF-α in serum samples of COPD patients.

RESULTS

In patients with COPD, both BODE index and FFMI presented significant positive and negative associations respectively with leptin levels (R(2) 0.61 and 0.65, respectively), whereas FFMI presented an additional negative association with the levels of TNF-α (R(2) 0.38). No significant associations were observed in smokers or ex-smokers with normal lung function.

CONCLUSIONS

Both BODE index and FFMI, are related to the circulating levels of leptin in patients with COPD, suggesting a possible role for leptin in the systemic component of COPD. The additional association of FFMI with TNF-α may further support a role of systemic inflammation in muscle wasting in COPD.

Increased levels of angiopoietins 1 and 2 in sputum supernatant in severe refractory asthma

BACKGROUND

Airway and vascular remodeling may play a prominent role in the clinical severity of severe refractory asthma (SRA). Angiopoietin-1 (Ang-1) is an essential mediator of angiogenesis by establishing vascular integrity, whereas angiopoietin-2 (Ang-2) acts as its natural inhibitor.

OBJECTIVE

We aimed to determine the levels of angiopoietins in sputum supernatants of patients with SRA and to investigate the possible associations with mediators and cells involved in both the inflammatory and the vascular remodeling processes.

METHODS

Thirty-eight patients with SRA, 35 patients with moderate asthma, and 20 healthy subjects were studied. All participants underwent lung function tests, bronchial hyperresponsiveness assessment and sputum induction for cell count identification and Ang-1, Ang-2, VEGF, TGF-β1, Cys-LTs, MMP-2, IL-13, ECP, and IL-8 measurement in supernatants. Airway vascular permeability (AVP) index was also assessed.

RESULTS

Ang-1 (ng/ml) and Ang-2 (pg/ml) levels were significantly elevated in patients with SRA compared with patients with moderate asthma and control subjects [median, interquartile ranges: 30 (17-39) vs 7.5 (5-11) vs 4.7 (3.8-5.9) respectively, P < 0.001; and 506 (400-700) vs 190 (146-236) vs 96 (89-120) respectively, P < 0.001]. Regression analysis showed a significant positive association between Ang-2 and AVP index, MMP-2, Ang-1, and VEGF in SRA. A weak association was also observed between Ang-1 and sputum eosinophils% in SRA.

CONCLUSION

Our results indicate that both angiopoietins levels are higher in SRA compared with moderate asthma and healthy subjects. In SRA, Ang-2 is associated with mediators involved in both the inflammatory and the vascular remodeling processes.

Exhaled nitric oxide and exhaled breath condensate pH as predictors of sputum cell counts in optimally treated asthmatic smokers

BACKGROUND AND OBJECTIVE

Smoking is thought to modify the pattern of airway inflammation. Induced sputum provides useful information on cellular phenotype in inflammatory airways disorders; however, it is time-consuming and difficult to implement in everyday clinical practice. The aim of this study was to determine whether exhaled NO (FeNO) and exhaled breath condensate (EBC) pH differed in asthmatic smokers compared with asthmatic non-smokers and healthy subjects, and to evaluate the performance of FeNO and EBC pH for predicting the cellular phenotype of induced sputum.

METHODS

Asthmatic smokers (n = 40) and non-smoking asthmatic patients (n = 43) were recruited for the study. Healthy smoking (n = 30) or non-smoking (n = 30) subjects served as controls. FeNO and EBC pH were measured and all subjects underwent sputum induction for assessment of cell counts.

RESULTS

EBC pH was significantly lower in asthmatic smokers compared with non-smokers (P < 0.01). FeNO levels were also significantly lower in asthmatic smokers compared with non-smokers (P < 0.001). EBC pH was inversely associated with sputum eosinophils in both asthmatic smokers and non-smokers (P < 0.001), whereas it was inversely associated with sputum neutrophils only in asthmatic smokers (P < 0.001). FeNO was positively associated with sputum eosinophils both in asthmatic smokers and non-smokers (P < 0.001) but was not associated with sputum neutrophils. In asthmatic smokers, FeNO was a better predictor of sputum eosinophilia, whereas EBC pH was a better predictor of sputum neutrophilia. A combination of FeNO ≤ 14 ppb together with EBC pH > 7.20 predicted the paucigranulocytic induced sputum phenotype.

CONCLUSIONS

EBC pH and FeNO levels were significantly lower in asthmatic smokers compared with non-smokers. Combined specific cut-off levels for FeNO and EBC pH may predict the paucigranulocytic phenotype in asthmatic smokers.

Induced sputum in asthma: from bench to bedside

During recent years there has been a growing interest in using non-invasive biomarkers to understand and monitor the airway inflammation in subjects with respiratory tract disorders and mainly asthma and chronic obstructive pulmonary disease (COPD). Sputum induction is generally a well-tolerated and safe procedure and a European Respiratory Society Task Force has published a comprehensive review on sputum methodology. Induced sputum cell count and, to a lesser extent, mediator measurements have been particularly well validated. In asthma, the sputum and the cell culture supernatant can be used for the measurement of a variety of soluble mediators, including eosinophil-derived proteins, nitric oxide (NO) derivatives, cytokines and remodelling-associated proteins. Sputum eosinophilia (> 3%) is a classic feature of asthma although half of the patients seems to be non eosinophilic. Measuring the percentage of sputum eosinophils has proved to be useful in the clinical arena in helping to predict short term response to inhaled corticosteroids (ICS) and tailor the dose of ICS in the severe patients but there is scope for the application of other induced sputum markers potentially useful in clinical practice. The widespread application of induced sputum in asthma across the spectrum of disease severity has given insight into the relationship between airway function and airway inflammation, proposed new disease phenotypes and defined which of these phenotypes respond to current therapy, and perhaps most importantly provided an additional tool to guide the clinical management of asthmatic patients. To date sputum induction is the only non-invasive measure of airway inflammation that has a clearly proven role in asthma management.

Oxidative stress in patients with COPD

The lung is the organ with the highest exposure to ambient air in the entire human architecture. Due to its large surface area and blood supply, the lung is susceptible to oxidative injury in the form of myriads of reactive oxygen species (ROS) and free radicals. In order to provide defense against the oxidative burden, the lungs produce various endogenous agents called antioxidants. The antioxidant species help the lungs ward off the deleterious consequences of a wide variety of oxidants/ROS, either of endogenous or environmental origin. Several mechanisms are related to the potential connection between COPD and oxidative stress. One of the most important actions of the oxidative stress is the influence of the molecular mechanisms involved in the expression proinflammatory genes. There is plenty of evidence supporting an imbalance between oxidants and antioxidants in the lung and systemic circulation of smokers and COPD patients. Detection of the oxidative burden and evaluation of their progression and phenotypes by oxidative stress biomarkers have proven challenging and difficult. Both invasive and non-invasive techniques have provided different biomarkers which contribute to the oxidative burden of the airways. An effective wide-spectrum antioxidant therapy with bioavailability is urgently needed to control the local and systemic oxidative burst in COPD. In that direction, several antioxidant agents have been evaluated as potential candidates for the management of COPD. However, despite some encouraging results, clinical trials so far have failed to elaborately define the type of antioxidant, the regimen and the time period of treatment that may improve clinically meaningful outcomes in patients with COPD.

Exhaled breath condensate pH as a biomarker of COPD severity in ex-smokers

Endogenous airway acidification, as assessed by exhaled breath condensate (EBC) pH, is present in patients with stable COPD. The aim of this study was to measure EBC pH levels in a large cohort of COPD patients and to evaluate associations with functional parameters according to their smoking status.EBC was collected from 161 patients with stable COPD and 112 controls (current and ex-smokers). EBC pH was measured after Argon deaeration and all subjects underwent pulmonary function testing.EBC pH was lower in COPD patients compared to controls [7.21 (7.02, 7.44) vs. 7.50 (7.40, 7.66); p < 0.001] and ex-smokers with COPD had lower EBC pH compared to current smokers [7.16 (6.89, 7.36) vs 7.24 (7.09, 7.54), p = 0.03]. In ex-smokers with COPD, EBC pH was lower in patients with GOLD stage III and IV compared to patients with stage I disease (p = 0.026 and 0.004 respectively). No differences were observed among current smokers with different disease severity. EBC pH levels in ex-smokers were associated with static hyperinflation (as expressed by IC/TLC ratio), air trapping (as expressed by RV/TLC ratio) and diffusing capacity for carbon monoxide, whereas no associations were observed in current smokers.Endogenous airway acidification is related to disease severity and to parameters expressing hyperinflation and air trapping in ex-smokers with COPD. The possible role of EBC pH in COPD needs to be further evaluated in longitudinal studies.

Hemoglobin, erythropoietin and systemic inflammation in exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Systemic inflammation may represent a possible cause of anemia. Previous data support that anemic patients with COPD present high erythropoietin (EPO) levels, suggestive of EPO resistance, possibly mediated through inflammatory mechanisms.

OBJECTIVES

We aimed to determine whether systemic inflammation, which is usually up-regulated during exacerbations of COPD (ECOPD) is associated with low hemoglobin levels expressing erythropoietin resistance.

METHODS

Hemoglobin (Hb), EPO and serum biomarkers of systemic inflammation [CRP, TNF-α, fibrinogen and IL-6] were assessed at three time points (admission, resolution and stable phases) in a selected cohort of 93 COPD patients.

RESULTS

Hemoglobin levels were significantly lower on admission compared to resolution and stable phases (median 12.1 g/dl [interquartile ranges 11.2-12.7], vs 13.5 [12.4-14.3] vs 13.4 [12.7-14.08], respectively p=0.002), whereas EPO was significantly higher on admission compared to resolution and stable phases. A negative association between Hb and IL-6 and a positive association between EPO and IL-6 were observed only during the acute phase of exacerbation. EPO and Hb were negatively associated during the acute phase, whereas they were positively associated during discharge and stable phase.

CONCLUSIONS

In this observational study we have shown that during admission for ECOPD Hb levels are decreased and EPO levels are increased. We have also identified a negative association between Hb and EPO. The above association is mainly related to increased IL-6 levels, indicating a possible EPO resistance through the mechanism of increased systemic inflammatory process.

The disparity of health facilities in an urban area discourages proposed treatment application in inoperable lung cancer patients

Objectives:

Patients with a newly diagnosed non-small cell lung cancer (NSCLC) stage IIIB are offered chemoradiotherapy, as proposed by the current guidelines. This combination treatment is facilitated by the coexistence of corresponding departments in the same establishment. The geographical disparity of these health facilities influences patients’ willingness to be treated and may influence their survival. This is an observational study that compares the survival of two groups of patients with NSCLC stage IIIB: those treated with chemoradiotherapy versus those treated only with chemotherapy. These two comparable groups were formed exclusively by patients’ and/or their families’ decisions.

Methods:

One hundred fifteen consecutive NSCLC stage IIIB patients were included in the study. All were hospitalized in the biggest Chest Disease Hospital in Athens and were offered sequential chemoradiotherapy. Only 54 patients opted for the proposed treatment, while 61 decided to be treated with chemotherapy only, denying continuing their treatment in another health care unit (radiotherapy). Their survival and related factors were analyzed.

Results:

Mean overall survival was estimated 10 months (95% confidence interval [CI]: 7.96–12.04). Patients treated with chemoradiotherapy had almost double overall survival compared to those under chemotherapy (P = 0.001): 13.6 months (95% CI: 12.3–14.9) versus 7.5 (95% CI: 6.1–8.9). Patients aged ≤ 65 years (P < 0.001), smokers (P < 0.001), and those without a cancer history (P < 0.001) survived longer.

Conclusions:

The lack of a radiotherapy department in a hospital providing chemotherapy impedes the application of current guidelines advocating combined radiochemotherapy. When recommended radiotherapy after six chemo cycles, half of the patients are unwilling to be displaced and do not follow the recommendations. This has an impact on patient survival.

Increased levels of osteopontin in sputum supernatant in severe refractory asthma

BACKGROUND

Osteopontin (OPN) is a glycoprotein that has been associated with inflammation and fibrosis. Severe refractory asthma (SRA) is characterised by an intense inflammatory and remodelling process. The aim of this study was to investigate the levels of OPN in sputum supernatants of patients with SRA, to compare them with milder forms of the disease and to investigate their possible association with mediators and cells involved in the inflammatory and remodelling process.

METHODS

33 patients with SRA, 29 with moderate asthma, 21 with steroid-naïve asthma and 20 healthy subjects were studied. All subjects underwent lung function tests, bronchial hyper-responsiveness assessment and sputum induction for cell count identification and measurement of OPN, vascular endothelial growth factor, transforming growth factor beta1 (TGF-beta1), cysteinyl leukotrienes, interleukin 13 (IL-13), eosinophilic cationic protein (ECP) and IL-8 in sputum supernatants.

RESULTS

Median (IQR) OPN levels (pg/ml) were significantly higher in patients with SRA than in those with moderate asthma, steroid-naive asthma and healthy control subjects (1840 (1125-11000) vs 130 (100-210) vs 100 (67-130) vs 50 (42-70), respectively, p<0.001). Regression analysis showed a significant association between log OPN and sputum eosinophils, cysteinyl leukotrienes, IL-13, TGF-beta1 and ECP. TGF-beta1 represented the strongest association with OPN. The above associations were not observed in milder forms of the disease or in healthy subjects.

CONCLUSIONS

The results indicate that OPN levels are higher in SRA than in less severe forms of the disease. Moreover, OPN is associated with mediators involved in both the inflammatory and remodelling process such as TGF-beta1, IL-13 and cysteinyl leukotrienes only in SRA.

Exhaled nitric oxide and exhaled breath condensate pH in severe refractory asthma

BACKGROUND

Distinct inflammatory cellular phenotypes of severe refractory asthma (SRA) have been reported. Fractional exhaled nitric oxide (FeNO) primarily is related to eosinophilic inflammation. Exhaled breath condensate (EBC) pH has been suggested as a noninvasive tool in the assessment of patients with asthma. We sought to determine whether FeNO and EBC pH could identify the presence and type of the underlying cellular inflammation in patients with SRA.

METHODS

Twenty-nine patients with SRA, 27 patients with moderate asthma, and 17 healthy subjects underwent FeNO measurement, EBC collection for pH measurement, and sputum induction for cell count identification.

RESULTS

FeNO was significantly higher and pH significantly lower in patients with SRA than in the other groups. In SRA, FeNO levels of > 19 parts per billion were associated with a sensitivity of 0.78 and a specificity of 0.73 for sputum eosinophilia, whereas FeNO levels of < 19 parts per billion were associated with a sensitivity of 0.63 and a specificity of 0.9 for sputum neutrophilia irrespective of the presence of eosinophils. The pH failed to predict the cellular profile in SRA, but a cutoff value of < 7.37 could predict sputum eosinophilia in moderate asthma.

CONCLUSIONS

In patients with SRA, different FeNO threshold values can identify those with predominant eosinophilia as well as those with neutrophilia. FeNO levels were reduced in patients with predominant neutrophilia regardless of the concomitant presence of eosinophilia. Although pH could not identify the cellular profile in SRA, it seemed to be a better index for predicting eosinophilia in moderate asthma.

Biomarkers obtained by non-invasive methods in patients with COPD: where do we stand, what do we expect?

Recently, there has been widespread interest in the use of non-invasive methods for the assessment of airway inflammation in a variety of lung diseases including chronic obstructive pulmonary disease (COPD). Sputum induction is a semi-invasive technique the value of which is not restricted to sputum cell counts, as inflammatory mediators can also be measured in the supernatants. However, none of the measurable biomarkers in induced sputum is considered applicable in clinical practice. Despite the predominating sputum neutrophilia, there is increasing evidence that the presence of sputum eosinophilia predicts an objective response to steroid treatment in patients with COPD. The commonly used Exhaled Breath Condensate (EBC) methodologies in COPD patients have considerable variability due to technical issues concerning both sample collection and analysis. Despite the above limitations, biomarkers mainly related to neutrophil derived products and oxidative stress, have been assessed for disease monitoring and response to pharmacological treatment. Endogenous airway acidification, as assessed by EBC pH, represents a measurable marker associated with oxidative stress and sputum neutrophilia. The fraction of exhaled nitric oxide (FeNO) is the most extensively studied exhaled biomarker and increased levels of FeNO have been widely documented in patients with asthma. FeNO measurement in COPD is of limited value due to smoking effect. However, increased values of FeNO have been found in COPD patients with sputum eosinophila. Moreover, measuring FeNO in different exhalation rates may reestablish its value in COPD. Despite the limited use of non-invasive methods, the future direction is a challenge towards new biomarkers or a combination of them that will assist us to move from the research laboratory to daily clinical practice.