Markers of inflammation and oxidative stress in exacerbated chronic obstructive pulmonary disease patients

Inflammation as the nexus: exploring the link between acute myocardial infarction and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), particularly following acute exacerbations (AE-COPD), significantly heightens the risks and mortality associated with acute myocardial infarction (AMI). The intersection of COPD and AMI is characterised by a considerable overlap in inflammatory mechanisms, which play a crucial role in the development of both conditions. Although extensive research has been conducted on individual inflammatory pathways in AMI and COPD, the understanding of thrombo-inflammatory crosstalk in comorbid settings remains limited. The effectiveness of various inflammatory components in reducing AMI infarct size or slowing COPD progression has shown promise, yet their efficacy in the context of comorbidity with COPD and AMI is not established. This review focuses on the critical importance of both local and systemic inflammation, highlighting it as a key pathophysiological connection between AMI and COPD/AE-COPD.

Potential of hydroethanolic leaf extract of Ocimum sanctum in ameliorating redox status and lung injury in COPD: an in vivo and in silico study

Oxidative stress and inflammation are hypothesised as the main contributor for Chronic Obstructive Pulmonary Disease (COPD). Cigarette smoke (CS), a major cause of COPD leads to inflammation resulting in recruitment of neutrophils and macrophages which are rich sources of oxidants. Activation of these cells produces excess oxidants and depletes antioxidants resulting in stress. Presently, effective drug for COPD is limited; therefore, novel compounds from natural sources, including plants are under exploration. The present study aims to investigate the protective effect of Ocimum sanctum leaf extract (OLE) in CS - induced model of COPD. Exposure to CS was performed thrice a week for 8 weeks and OLE (200 mg/kg and 400 mg/kg) was administered an hour before CS exposure. Control group (negative control) were exposed to ambient air while COPD group was exposed to CS (positive control). Administration of OLE doses reduced inflammation, decreased oxidant concentration and increased antioxidant concentration (p < 0.01). Molecular docking studies between the major phytocompounds of OLE (Eugenol, Cyclohexane and Caryophyllene) and antioxidant enzymes Superoxide dismutase (SOD), Catalase, Glutathione peroxidase (GPx), Glutathione reductase (GR) and Glutathione S Transferase (GST) showed strong binding interaction in terms of binding energy. In vivo and in silico findings for the first time indicates that OLE extract significantly alleviates oxidative stress by its potent free radical scavenging property and strong interaction with antioxidant enzymes. OLE extract may prove to be a therapeutic option for COPD prevention and treatment.

Tanimilast, A Novel Inhaled Pde4 Inhibitor for the Treatment of Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases are the third leading cause of death, behind cardiovascular diseases and cancer, affecting approximately 550 million of people all over the world. Most of the chronic respiratory diseases are attributable to asthma and chronic obstructive pulmonary disease (COPD) with this latter being the major cause of deaths. Despite differences in etiology and symptoms, a common feature of asthma and COPD is an underlying degree of airways inflammation. The nature and severity of this inflammation might differ between and within different respiratory conditions and pharmacological anti-inflammatory treatments are unlikely to be effective in all patients. A precision medicine approach is needed to selectively target patients to increase the chance of therapeutic success. Inhibitors of the phosphodiesterase 4 (PDE4) enzyme like the oral PDE4 inhibitor roflumilast have shown a potential to reduce inflammatory-mediated processes and the frequency of exacerbations in certain groups of COPD patients with a chronic bronchitis phenotype. However, roflumilast use is dampened by class related side effects as nausea, diarrhea, weight loss and abdominal pain, resulting in both substantial treatment discontinuation in clinical practice and withdrawal from clinical trials. This has prompted the search for PDE4 inhibitors to be given by inhalation to reduce the systemic exposure (and thus optimize the systemic safety) and maximize the therapeutic effect in the lung. Tanimilast (international non-proprietary name of CHF6001) is a novel highly potent and selective inhaled PDE4 inhibitor with proven anti-inflammatory properties in various inflammatory cells, including leukocytes derived from asthma and COPD patients, as well as in experimental rodent models of pulmonary inflammation. Inhaled tanimilast has reached phase III clinical development by showing promising pharmacodynamic results associated with a good tolerability and safety profile, with no evidence of PDE4 inhibitors class-related side effects. In this review we will discuss the main outcomes of preclinical and clinical studies conducted during tanimilast development, with particular emphasis on the characterization of the pharmacodynamic profile that led to the identification of target populations with increased therapeutic potential in inflammatory respiratory diseases.

Reactive Oxygen Species and Antioxidative Defense in Chronic Obstructive Pulmonary Disease

The respiratory system is continuously exposed to endogenous and exogenous oxidants. Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways, leading to the destruction of lung parenchyma (emphysema) and declining pulmonary function. It is increasingly obvious that reactive oxygen species (ROS) and reactive nitrogen species (RNS) contribute to the progression and amplification of the inflammatory responses related to this disease. First, we described the association between cigarette smoking, the most representative exogenous oxidant, and COPD and then presented the multiple pathophysiological aspects of ROS and antioxidative defense systems in the development and progression of COPD. Second, the relationship between nitric oxide system (endothelial) dysfunction and oxidative stress has been discussed. Third, we have provided data on the use of these biomarkers in the pathogenetic mechanisms involved in COPD and its progression and presented an overview of oxidative stress biomarkers having clinical applications in respiratory medicine, including those in exhaled breath, as per recent observations. Finally, we explained the findings of recent clinical and experimental studies evaluating the efficacy of antioxidative interventions for COPD. Future breakthroughs in antioxidative therapy may provide a promising therapeutic strategy for the prevention and treatment of COPD.

Chemiluminescent Measurement of Hydrogen Peroxide in the Exhaled Breath Condensate of Healthy and Asthmatic Adults

Reactive oxygen species are centrally involved in the pathophysiology of airway diseases such as asthma and chronic obstructive pulmonary disease. This study reports the development of a chemiluminescence assay and a device for measuring hydrogen peroxide in the exhaled breath condensate of asthma patients and healthy participants. A stand-alone photon detection device was constructed for use with an optimized chemiluminescence assay. Calibrations using a catalase control to scavenge residual hydrogen peroxide in calibrant solutions provided analytically sensitive and specific measurements. We evaluated exhaled breath condensate hydrogen peroxide in 60 patients (ages 20-83; 30 healthy patients and 30 asthma patients) recruited from the John Peter Smith Hospital Network. The exhaled breath condensate hydrogen peroxide concentrations trended toward higher values in asthma patients compared to healthy participants (mean 142.5 vs 115.5 nM; p = 0.32). Asthma patients who had not used an albuterol rescue inhaler in the past week were compared to those who had and showed a trend toward higher hydrogen peroxide levels (mean 172.8 vs 115.9 nM; p = 0.25), and these patients also trended toward higher hydrogen peroxide than healthy participants (mean 172.8 vs 115.5 nM; p = 0.14). This pilot study demonstrates the ability of the newly developed assay and device to measure exhaled breath condensate hydrogen peroxide in asthma patients and healthy participants. The trends observed in this study are in agreement with previous literature and warrant further investigation of using this system to measure exhaled breath condensate hydrogen peroxide for monitoring oxidative stress in asthma.

Oxidative damage mediates the association between polycyclic aromatic hydrocarbon exposure and lung function

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) is related to decreased lung function. However, whether oxidative damage is involved in this relationship remains unclear. This study was aimed to explore the potential mediating role of oxidative DNA or lipid damage in the association between PAH exposure and lung function.

METHODS

The urinary levels of monohydroxy polycyclic aromatic hydrocarbon metabolites (OH-PAHs) and lung function parameters were measured among 3367 participants from the baseline of the Wuhan-Zhuhai cohort. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane (8-iso-PGF2α) were determined to evaluate the individuals' oxidative DNA and lipid damage degrees, respectively. Linear mixed models were used to investigate the associations of urinary OH-PAHs, 8-OHdG and 8-iso-PGF2α with lung function parameters. Mediation analysis was further conducted to assess the potential role of oxidative damage in the association between urinary OH-PAHs and lung function.

RESULTS

Each one-percentage increase in the sum of urinary OH-PAHs, high-molecular-weight or low-molecular-weight OH-PAHs (ƩOH-PAHs, ƩHMW OH-PAH or ƩLMW OH-PAHs, respectively) was associated with a 0.2152-, 0.2076- or 0.1985- ml decrease in FEV₁, and a 0.1891-, 0.2195- or 0.1634- ml decrease in FVC, respectively. Additionally, significantly positive dose-response relationships of ƩOH-PAHs, ƩHMW OH-PAH and ƩLMW OH-PAHs with urinary 8-OHdG or 8-iso-PGF2α, as well as an inverse dose-response relationship between urinary 8-OHdG and FVC, were observed (all P for trend < 0.05). Mediation analysis indicated that urinary 8-OHdG mediated 14.22% of the association between ƩHMW OH-PAH and FVC.

CONCLUSION

Higher levels of oxidative DNA damage might be involved in the decreased levels of FVC caused by high-molecular-weight PAH exposure.

Sputum and blood transcriptomics characterisation of the inhaled PDE4 inhibitor CHF6001 on top of triple therapy in patients with chronic bronchitis

Background

Although phosphodiesterase-4 (PDE4) inhibitors have been shown to reduce COPD exacerbation rate, their biological mechanism of action is not completely elucidated at the molecular level. We aimed to characterise the whole genome gene expression profile of the inhaled PDE4-inhibitor CHF6001 on top of triple therapy in sputum cells and whole blood of patients with COPD and chronic bronchitis.

Methods

Whole genome gene expression analysis was carried out by microarray in 54 patients before and after 32 days treatment with CHF6001 800 and 1600 μg and placebo twice daily (BID) in a randomised crossover study.

Results

CHF6001 had a strong effect in sputum, with 1471 and 2598 significantly differentially-expressed probe-sets relative to placebo (p-adjusted for False Discovery Rate < 0.05) with 800 and 1600 μg BID, respectively. Functional enrichment analysis showed significant modulation of key inflammatory pathways involved in cytokine activity, pathogen-associated-pattern-recognition activity, oxidative stress and vitamin D with associated inhibition of downstream inflammatory effectors. A large number of pro-inflammatory genes coding for cytokines and matrix-metalloproteinases were significantly differentially expressed for both doses; the majority (> 87%) were downregulated, including macrophage inflammatory protein-1-alpha and 1-beta, interleukin-27-beta, interleukin-12-beta, interleukin-32, tumour necrosis factor-alpha-induced-protein-8, ligand-superfamily-member-15, and matrix-metalloproteinases-7,12 and 14. The effect in blood was not significant.

Conclusions

Inhaled PDE4 inhibition by CHF6001 on top of triple therapy in patients with COPD and chronic bronchitis significantly modulated key inflammatory targets and pathways in the lung but not in blood. Mechanistically these findings support a targeted effect in the lung while minimising unwanted systemic class-effects.

Trial registration

ClinicalTrial.gov, EudraCT, 2015–005550-35. Registered 15 July 2016.

Toward Continuous Monitoring of Breath Biochemistry: A Paper-Based Wearable Sensor for Real-Time Hydrogen Peroxide Measurement in Simulated Breath

Exhaled breath contains a large amount of biochemical and physiological information concerning one's health and provides an alternative route to noninvasive medical diagnosis of diseases. In the case of lung diseases, hydrogen peroxide (H2O2) is an important biomarker associated with asthma, chronic obstructive pulmonary disease, and lung cancer and can be detected in exhaled breath. The current method of breath analysis involves condensation of exhaled breath, is not continuous or real time, and requires two separate and bulky devices, complicating the periodic or long-term monitoring of a patient. We report the first disposable paper-based electrochemical wearable sensor that can monitor exhaled H2O2 in artificial breath calibration-free and continuously, in real time, and can be integrated into a commercial respiratory mask for on-site testing of exhaled breath. To improve precision for sensing H2O2, we perform differential electrochemical measurement by amperometry in which screen-printed Prussian Blue-mediated and nonmediated carbon electrodes are used for differential analysis. We were able to measure H2O2 in simulated breath in a concentration-dependent manner in real time, confirming its functionality. This proposed system is versatile, and by modifying the chemistry of the sensing electrodes, our method of differential sensing can be extended to continuous monitoring of other analytes in exhaled breath.

Is oxidative stress associated with disease severity, pulmonary function and metabolic syndrome in chronic obstructive pulmonary disease?

OBJECTIVE

To investigate associations between oxidant/antioxidant biomarkers with the disease severity, pulmonary function and diagnosis of metabolic syndrome (MetS) in patients with COPD.

METHODS

Seventy-four subjects were included, 39 with COPD (age 69±7 years; female 41%) and 35 for control group (age 69±7 years; female 43%). They were diagnosed with MetS and allocated in one of 4 subgroups: COPD and control, with and without MetS, respectively. Advanced oxidation protein products (AOPP), paraoxonase-1, catalase activity, sulfhydryl group and total lipid hydroperoxide were assayed. Pulmonary function was performed with a plethysmograph.

RESULTS

COPD severity (GOLD≥3) and pulmonary function were associated with sulfhydryl group and AOPP (P≤.03 for all). The prevalence of MetS was associated with AOPP in COPD (P=.04). Individuals with COPD and MetS showed higher AOPP compared to COPD without MetS (P<.0001).

CONCLUSION

COPD severity, worse pulmonary function and presence of metabolic syndrome are associated with oxidative stress in individuals with COPD.

Inference of Cellular Immune Environments in Sputum and Peripheral Blood Associated with Acute Exacerbations of COPD

Introduction

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States, with high associated costs. Most of the cost burden results from acute exacerbations of COPD (AE-COPD), events associated with heightened symptoms and mortality. Cellular mechanisms underlying AE-COPD are poorly understood, likely because they arise from dysregulation of complex immune networks across multiple tissue compartments.

Methods

To gain systems-level insight into cellular environments relevant to exacerbation, we applied data-driven modeling approaches to measurements of immune factors (cytokines and flow cytometry) measured previously in two different human tissue environments (sputum and peripheral blood) during the stable and exacerbated state.

Results

Using partial least squares discriminant analysis, we identified a unique signature of cytokines in serum that differentiated stable and AE-COPD better than individual measurements. Furthermore, we found that models integrating data across tissue compartments (serum and sputum) trended towards being more accurate. The resulting paracrine signature defining AE-COPD events combined elevations of proteins associated with cell adhesion (sVCAM-1, sICAM-1) and increased levels of neutrophils and dendritic cells in blood with elevated chemoattractants (IP-10 and MCP-2) in sputum.

Conclusions

Our results supported a new hypothesis that AE-COPD is driven by immune cell trafficking into the lung, which requires expression of cell adhesion molecules and raised levels of innate immune cells in blood, with parallel upregulated expression of specific chemokines in pulmonary tissue. Overall, this work serves as a proof-of-concept for using data-driven modeling approaches to generate new insights into cellular processes involved in complex pulmonary diseases.

Oxidative stress and macrophages: driving forces behind exacerbations of asthma and chronic obstructive pulmonary disease?

Oxidative stress is a common feature of obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Lung macrophages are key innate immune cells that can generate oxidants and are known to display aberrant polarization patterns and defective phagocytic responses in these diseases. Whether these characteristics are linked in one way or another and whether they contribute to the onset and severity of exacerbations in asthma and COPD remain poorly understood. Insight into oxidative stress, macrophages, and their interactions may be important in fully understanding acute worsening of lung disease. This review therefore highlights the current state of the art regarding the role of oxidative stress and macrophages in exacerbations of asthma and COPD. It shows that oxidative stress can attenuate macrophage function, which may result in impaired responses toward exacerbating triggers and may contribute to exaggerated inflammation in the airways.

Associations of urinary polycyclic aromatic hydrocarbon metabolites with fractional exhaled nitric oxide and exhaled carbon monoxide: A cross-sectional study

Exposure to Polycyclic aromatic hydrocarbons (PAHs) has been associated with inflammatory responses. Fractional exhaled nitric oxide (FeNO) and exhaled carbon monoxide (eCO) are both important inflammatory mediators especially in airways. However, few studies have investigated associations of PAH exposures with FeNO or eCO. Therefore, we aimed to quantify the associations of urinary PAH metabolites with FeNO and eCO levels, and investigate their potential effect modifiers by linear mixed models among 4133 participants from the Wuhan-Zhuhai cohort in China. We further performed stratified analyses to estimate effect modification. We found significant associations of increased urinary PAH metabolites with elevated eCO and FeNO. Among all participants, each 1% increase of 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxyphenanthrene, and total PAH metabolites was significantly associated with a 12.6% (95% confidence interval: 9.3%, 15.9%), 9.7% (6.5%, 12.9%), 7.5% (4.1%, 10.9%), 3.2% (0.2%, 6.2%), 2.7% (0.1%, 5.3%), and 6.5% (2.7%, 10.4%) increased eCO level, respectively; while each 1% increase of urinary 1-hydroxynaphthalene, 9-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 2-hydroxyphenanthrene was associated with a -3.0% (-5.8%, -0.2%), 2.9% (0.3%, 5.6%), 3.2% (1.0%, 5.4%), and 4.5% (2.2%, 6.9%) change of FeNO level, respectively. Positive associations between certain urinary PAH metabolites and eCO were observed among both ever-smokers and non-smokers, and the associations were stronger among ever-smokers than that among non-smokers. Increased urinary PAH metabolites were associated with decreased FeNO among ever-smokers and elevated FeNO levels among non-smokers. Our findings suggest that PAH exposures may impair airway through inducing inflammatory response, especially among ever-smokers.

Biomarkers related to respiratory symptoms and lung function in adults with asthma

BACKGROUND

There is a need for easily measurable biomarkers that are able to identify different levels of asthma severity.

AIM

To assess the association between peripheral blood cell counts, fractional nitric oxide in exhaled air (FeNO), urinary biomarkers of oxidative stress (8-hydroxy-2'-deoxyguanosine and 8-isoprostane), and asthma severity in adult patients from the general population.

METHODS

In the Gene Environment Interactions in Respiratory Diseases study, 287 subjects with asthma (aged 20-64) were identified from the general population in Verona (Italy) (2008-2010). Self-reported asthma attacks, asthma-like symptoms and the use of hospital services in the past year were synthesized in a score of respiratory symptoms (SRS). The association of biomarkers with SRS and lung function measures (pre-bronchodilator FEV₁% predicted and FEV₁/FVC) was assessed using quasi-Poisson and Gaussian regression models, respectively.

RESULTS

Eosinophils (ratio of expected scores: RES[95%CI] = 1.19[1.09,1.30]), basophils (RES[95%CI] = 1.24[1.10,1.40]), lymphocytes (RES[95%CI] = 1.27[1.12,1.45]) and FeNO (RES[95%CI] = 1.18[1.02,1.37]) were positively associated with SRS. However, only eosinophils (RES[95%CI] = 1.15[1.02,1.30]) and lymphocytes (RES[95%CI] = 1.25[1.06,1.47]) showed an independent association. Furthermore, eosinophils (change in the expected outcome for 1-SD increase: CEO[95%CI] = -1.18[-2.09, -0.27]%), basophils (CEO[95%CI] = -1.24[-2.16, -0.33]%) and lymphocytes (CEO[95%CI] = -1.07[-1.99, -0.14]%) were individually, but not independently, associated with FEV₁/FVC. Finally, neutrophils were negatively associated with FEV₁% predicted (CEO[95%CI] = -2.22[-4.00, -0.44]%).

CONCLUSIONS

We identified a pattern of association between a set of biomarkers and asthma endotypes in adult patients from the general population, which could improve understanding of the heterogeneity and severity of the disease and could be useful in defining targeted therapeutic approaches.

Urinary polycyclic aromatic hydrocarbon metabolites, Club cell secretory protein and lung function

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with lung function decline. However, the underlying mechanisms for the association remain unclear.

OBJECTIVES

To explore potential role of a lung epithelial biomarker, Club cell secretory protein (CC16), in associations between PAH exposures and lung function decline.

METHODS

We investigated 3384 adults from the Wuhan-Zhuhai cohort, and followed up at three years after first examination. Linear mixed models was used to quantify dose-response relationships between urinary monohydroxylated PAH metabolites (OH-PAHs) and lung function, as well as OH-PAHs and plasma CC16. Mediation analysis was conducted to investigate role of CC16 in the association between OH-PAHs and lung function. We also estimated the relationships between OH-PAHs and lung function change in three years among participants with different levels of CC16.

RESULTS

Each 1-unit increase of log-transformed total urinary high and low molecular weight OH-PAHs (∑HMW OH-PAH and ∑LMW OH-PAHs) were associated with a 22.59 and 25.25ml reduction of FEV₁ respectively, while∑HMW OH-PAH was associated with a 30.38ml reduction of FVC. Moreover, these negative associations between OH-PAHs and lung function levels were significant only among low CC16 group (<15.83ng/ml). CC16 concentration decreased monotonically with increased high molecular weight OH-PAHs (∑HMW OH-PAHs) when ∑HMW OH-PAH concentration was over 0.67μg/mmol Cr. CC16 mediated 22.13% of the association between ∑HMW OH-PAH and FVC among individuals with higher ∑HMW OH-PAH. After three years of follow-up, subjects with low level of plasma CC16 had a significant decline of FVC when exposed to high level of ∑HMW OH-PAH.

CONCLUSIONS

CC16 play an important role in the association between high molecular weight PAHs and FVC. Individuals with low plasma CC16 level might suffer a decline in lung function when exposed to high level of high molecular weight PAHs.

Increased Exhaled H2O2 and Impaired Lung Function in Patients Undergoing Bioincompatible Hemodialysis

Background

Chronic renal failure (CRF) and hemodialysis (HD) accumulate an inflammatory milieu, contributing to increased systemic and airway oxidative stress that may lead to lung damage.

Objectives

This study was designed to assess exhaled hydrogen peroxide (H2O2), lung function and whole blood chemiluminescence in HD and CRF patients and healthy controls.

Methods

The study included 59 patients (Polyamide S™ or Hemophan® membranes-19, cuprophane-16, hemodiafiltration-14, continuous ambulatory peritoneal dialysis-10), 16 CRF and 16 healthy controls. The assessment of lung function included FVC (forced vital capacity), FEV1 (forced expiratory volume in the first second) and DLCOc (single breath CO diffusing capacity). Exhaled H2O2 was determined fluorometrically and resting and n-formyl-methionyl-leucyl-phenylalanine (fMLP) luminol-dependent whole blood chemiluminescence (LBCL) were measured simultaneously.

Results

Only cuprophane HD patients presented decreased lung function (FVC 63.8±17.4%, FEV1 55.9±20.3 and DLCOc 72.1± 9.3 % of predicted; p<0.05 vs. controls). These patients exhaled the highest H2O2 levels in comparison to CRF (p<0.01): median 0.36 μM (range R: 0.09–0.56 μM) and controls (p<0.05): 0.17 μM (0.2–17.8 μM). These levels were not decreased during the HD session: preHD 1.25 μM (0.2–16.5μM) and postHD 1.3 μM (0.2–17.8 μM). As a marker of systemic oxidative stress, fMLP-induced LBCL (total light emission) was increased in these patients (1570.6 aUxs /10phagocytes; R: 274.2–8598.9) and in the CRF group (2389.4 aUxs /10phagocytes; R: 491.5–6184; p<0.05 vs. controls). Other patient groups did not express elevated LBCL and revealed decreased exhaled H2O2 after a session.

Conclusions

An increased oxidative burden in the lungs may contribute to functional lung impairment in patients dialyzed with a cellulose membrane. Biocompatible dialysis with other modalities might reduce airway-borne oxidative stress and is not related with lung damage.

Relationship of serum levels of interleukin 6, interleukin 8, and C-reactive protein with forced expiratory volume in first second in patients with mustard lung and chronic obstructive pulmonary diseases: systematic review and meta-analysis

INTRODUCTION

The chronic systemic inflammation is a result of releasing inflammatory cytokines from the cells relating to the body immunity system and chronic activation of the innate immunity system.

AIM

To evaluate the relationship among serum levels of interleukin 6 (IL-6), interleukin 8 (IL-8), C-reactive protein (CRP) with forced expiratory volume in 1st s (FEV1) in patients with mustard lung (ML) and chronic obstructive pulmonary diseases (COPD).

MATERIAL AND METHODS

A published literature search was performed through SID, web of science, ISI, Science Direct, Scopus, Medline, and PubMed databases for articles published in English. The correlation coefficient (r) and 95% confidence intervals (95% CIs) were calculated using random or fixed effects models. Heterogeneity was assessed using χ2 and I2 statistics.

RESULTS

In total, 4 published studies were included in the final analysis. Using the random-effect model, meta-analysis showed that the r was -0.052 (95% CI: -0.14-0.049, p = 0.28) at serum level of IL-8, serum levels of CRP and FEV1 in these results were r = -0.13, p = 0.012, serum levels of tumor necrosis factor (TNF) and FEV1 levels were r = -0.39, p = 0.03 in the conducted studies on mustard lung patients. The IL-6 serum level was explored in COPD patients. The results of the given studies in these patients are r = -0.006, 95% CI: -0.37-0.15, and p = 0.44.

CONCLUSIONS

In this meta-analysis, there was evidence that serum levels of CRP and TNF have been significantly increased in chronic obstructive pulmonary diseases compared to the healthy control group, which signifies the presence of systemic inflammation in ML and COPD patients.

Asiatic acid inhibits pulmonary inflammation induced by cigarette smoke

Asiatic acid (AA) is one of the major components of Titrated extract of Centella asiatica (TECA), which has been reported to possess antioxidant and anti-inflammatory activities. The purpose of this study was to investigate the protective effect of AA on pulmonary inflammation induced by cigarette smoke (CS). AA significantly attenuated the infiltration of inflammatory cells in bronchoalveolar lavage fluid (BALF) of CS exposure mice. AA also decreased ROS production and NE activity, and inhibited the release of proinflammatory cytokines in BALF. AA reduced the recruitment of inflammatory cells and MCP-1 expression in lung tissue of CS exposure mice. AA also attenuated mucus overproduction, and decreased the activation of MAPKs and NF-kB in lung tissue. Furthermore, AA increased HO-1 expression and inhibited the reduced expression of SOD3 in lung tissue. These findings indicate that AA effectively inhibits pulmonary inflammatory response, which is an important process in the development of chronic obstructive pulmonary disease (COPD) via suppression of inflammatory mediators and induction of HO-1. Therefore, we suggest that AA has the potential to treat inflammatory disease such as COPD.

Review on Exhaled Hydrogen Peroxide as a Potential Biomarker for Diagnosis of Inflammatory Lung Diseases

Exhaled breath (EB) contains thousands of volatile and nonvolatile biomolecules. EB analysis is non-invasive and convenient to patients than blood or urine tests. The exhaled biomolecules have long been studied and recognized to have some potential biomarkers for diagnosis of diseases, evaluation of metabolic disorders and monitoring drug efficiency. For instance, Biomarkers such as exhaled hydrogen peroxide (H2O2) and exhaled nitric oxide are associated with inflammatory lung diseases, ammonia is used as a biomarker for kidney diseases and exhaled acetone is related to glucose concentration in blood and so it is used for diabetes diagnosis. H2O2 concentration in EB increases with the severity of lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and adult respiratory distress syndrome (ARDS). Different methods are used to measure H2O2 in exhaled breath condensate (EBC). In EBC the EB is collected in a condensate unit and then H2O2 concentration in the collected sample is detected using titrimetric, spectrophotometry, fluorescence, chemiluminescence and electrochemical sensors. Recently, some works have been done to measure the concentration of H2O2 in its vapor phase without a need for condensation units. The aim of this paper is to review and summarize the current methods being used to measure the concentration of H2O2 in EB to identify inflammatory lung diseases, and to discuss the advantages and disadvantages of these methods

Proteomic differences with and without ozone-exposure in a smoking-induced emphysema lung model

BACKGROUND/AIMS

Acute exacerbations in chronic obstructive pulmonary disease may be related to air pollution, of which ozone is an important constituent. In this study, we investigated the protein profiles associated with ozone-induced exacerbations in a smoking-induced emphysema model.

METHODS

Mice were divided into the following groups: group I, no smoking and no ozone (NS + NO); group II, no smoking and ozone (NS + O); group III, smoking and no ozone (S + NO); and group IV, smoking and ozone (S + O). Bronchoalveolar lavage, the mean linear intercept (MLI) on hematoxylin and eosin staining, nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS), and Western blotting analyses were performed.

RESULTS

The MLIs of groups III (S + NO) and IV (S + O) (45 ± 2 and 44 ± 3 µm, respectively) were significantly higher than those of groups I (NS + NO) and II (NS + O) (26 ± 2 and 23 ± 2 µm, respectively; p < 0.05). Fourteen spots that showed significantly different intensities on image analyses of two-dimensional (2D) protein electrophoresis in group I (NS + NO) were identified by LC-MS/MS. The levels of six proteins were higher in group IV (S + O). The levels of vimentin, lactate dehydrogenase A, and triose phosphate isomerase were decreased by both smoking and ozone treatment in Western blotting and proteomic analyses. In contrast, TBC1 domain family 5 (TBC1D5) and lamin A were increased by both smoking and ozone treatment.

CONCLUSIONS

TBC1D5 could be a biomarker of ozone-induced lung injury in emphysema.

Oxidative stress and free radicals in COPD--implications and relevance for treatment

Oxidative stress occurs when free radicals and other reactive species overwhelm the availability of antioxidants. Reactive oxygen species (ROS), reactive nitrogen species, and their counterpart antioxidant agents are essential for physiological signaling and host defense, as well as for the evolution and persistence of inflammation. When their normal steady state is disturbed, imbalances between oxidants and antioxidants may provoke pathological reactions causing a range of nonrespiratory and respiratory diseases, particularly chronic obstructive pulmonary disease (COPD). In the respiratory system, ROS may be either exogenous from more or less inhalative gaseous or particulate agents such as air pollutants, cigarette smoke, ambient high-altitude hypoxia, and some occupational dusts, or endogenously generated in the context of defense mechanisms against such infectious pathogens as bacteria, viruses, or fungi. ROS may also damage body tissues depending on the amount and duration of exposure and may further act as triggers for enzymatically generated ROS released from respiratory, immune, and inflammatory cells. This paper focuses on the general relevance of free radicals for the development and progression of both COPD and pulmonary emphysema as well as novel perspectives on therapeutic options. Unfortunately, current treatment options do not suffice to prevent chronic airway inflammation and are not yet able to substantially alter the course of COPD. Effective therapeutic antioxidant measures are urgently needed to control and mitigate local as well as systemic oxygen bursts in COPD and other respiratory diseases. In addition to current therapeutic prospects and aspects of genomic medicine, trending research topics in COPD are presented.

Increased of exhaled breath condensate neutrophil chemotaxis in acute exacerbation of COPD

Background

Neutrophils have been involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Underlying mechanisms of neutrophil accumulation in the airways of stable and exacerbated COPD patients are poorly understood. The aim of this study was to assess exhaled breath condensate (EBC) neutrophil chemotactic activity, the level of two chemoattractants for neutrophils (GRO-α and LTB4) during the course of an acute exacerbation of COPD (AECOPD).

Methods

50 ex smoking COPD patients (33 with acute exacerbation and 17 in stable disease) and 20 matched ex smoking healthy controls were compared. EBC was collected by using a commercially available condenser (EcoScreen®). EBC neutrophil chemotactic activity (NCA) was assessed by using Boyden microchambers. Chemotactic index (CI) was used to evaluate cell migration. LTB₄ and GROα levels were measured by a specific enzyme immunoassay in EBC.

Results

Stable COPD and outpatients with AECOPD, but not hospitalized with AECOPD, had raised EBC NCA compared to healthy subjects (p < 0.05 and p < 0.01 respectively). In outpatients with AECOPD EBC NCA significantly decreased 6 weeks after the exacerbation. Overall EBC NCA was weakly correlated with sputum neutrophil counts (r = 0.26, p < 0.05).

EBC LTB4 levels were increased in all groups of COPD compared to healthy subjects while GRO-α was only raised in patients with AECOPD. Furthermore, EBC LTB₄ and GRO-α significantly decreased after recovery of the acute exacerbation. Increasing concentrations (0.1 to 10 μg/mL) of anti- human GRO-α monoclonal antibody had no effect on EBC neutrophil chemotactic activity of 10 exacerbated COPD patients.

Conclusions

EBC NCA rose during acute exacerbation of COPD in ambulatory patients and decreased at recovery. While LTB4 seems to play a role both in stable and in exacerbated phase of the disease, the role of GRO-α as a chemotactic factor during AECOPD is not clearly established and needs further investigation.

The Gillings Sampler--an electrostatic air sampler as an alternative method for aerosol in vitro exposure studies

There is growing interest in studying the toxicity and health risk of exposure to multi-pollutant mixtures found in ambient air, and the U.S. Environmental Protection Agency (EPA) is moving towards setting standards for these types of mixtures. Additionally, the Health Effects Institute's strategic plan aims to develop and apply next-generation multi-pollutant approaches to understanding the health effects of air pollutants. There's increasing concern that conventional in vitro exposure methods are not adequate to meet EPA's strategic plan to demonstrate a direct link between air pollution and health effects. To meet the demand for new in vitro technology that better represents direct air-to-cell inhalation exposures, a new system that exposes cells at the air-liquid interface was developed. This new system, named the Gillings Sampler, is a modified two-stage electrostatic precipitator that provides a viable environment for cultured cells. Polystyrene latex spheres were used to determine deposition efficiencies (38-45%), while microscopy and imaging techniques were used to confirm uniform particle deposition. Negative control A549 cell exposures indicated the sampler can be operated for up to 4h without inducing any significant toxic effects on cells, as measured by lactate dehydrogenase (LDH) and interleukin-8 (IL-8). A novel positive aerosol control exposure method, consisting of a p-tolualdehyde (TOLALD) impregnated mineral oil aerosol (MOA), was developed to test this system. Exposures to the toxic MOA at a 1 ng/cm(2) dose of TOLALD yielded a reproducible 1.4 and 2-fold increase in LDH and IL-8 mRNA levels over controls. This new system is intended to be used as an alternative research tool for aerosol in vitro exposure studies. While further testing and optimization is still required to produce a "commercially ready" system, it serves as a stepping-stone in the development of cost-effective in vitro technology that can be made accessible to researchers in the near future.

Pulmonary biomarkers in COPD exacerbations: a systematic review

Exacerbations of COPD (ECOPD) represent a major burden for patients and health care systems. Innovative sampling techniques have led to the identification of several pulmonary biomarkers. Although some molecules are promising, their usefulness in clinical practice is not yet established. Medline and Highwire databases were used to identify studies evaluating pulmonary sampled biomarkers in ECOPD. We combined 3 terms for ECOPD, 3 for biomarkers and 6 for the sampling method. Seventy-nine studies were considered eligible for inclusion in the review and were analyzed further. Pulmonary biomarkers sampled with non-invasive, semi-invasive and invasive methods were evaluated for their potential to illustrate the disease's clinical course, to correlate to clinical variables and to predict clinical outcomes, ECOPD etiology and response to treatment. According to published data several pulmonary biomarkers assessed in ECOPD have the potential to illustrate the natural history of disease through the modification of their levels. Among the clinically relevant molecules, those that have been studied the most and appear to be promising are spontaneous and induced sputum biomarkers for reflecting clinical severity and symptomatic recovery, as well as for directing towards an etiological diagnosis. Current evidence on the clinical usefulness of exhaled breath condensate and bronchoalveolar lavage biomarkers in ECOPD is limited. In conclusion, pulmonary biomarkers have the potential to provide information on the mechanisms underlying ECOPD, and several correlate with clinical variables and outcomes. However, on the basis of published evidence, no single molecule is adequately validated for wide clinical use. Clinical trials that incorporate biomarkers in decisional algorithms are required.

Gene expression profiling following NRF2 and KEAP1 siRNA knockdown in human lung fibroblasts identifies CCL11/Eotaxin-1 as a novel NRF2 regulated gene

Background

Oxidative Stress contributes to the pathogenesis of many diseases. The NRF2/KEAP1 axis is a key transcriptional regulator of the anti-oxidant response in cells. Nrf2 knockout mice have implicated this pathway in regulating inflammatory airway diseases such as asthma and COPD. To better understand the role the NRF2 pathway has on respiratory disease we have taken a novel approach to define NRF2 dependent gene expression in a relevant lung system.

Methods

Normal human lung fibroblasts were transfected with siRNA specific for NRF2 or KEAP1. Gene expression changes were measured at 30 and 48 hours using a custom Affymetrix Gene array. Changes in Eotaxin-1 gene expression and protein secretion were further measured under various inflammatory conditions with siRNAs and pharmacological tools.

Results

An anti-correlated gene set (inversely regulated by NRF2 and KEAP1 RNAi) that reflects specific NRF2 regulated genes was identified. Gene annotations show that NRF2-mediated oxidative stress response is the most significantly regulated pathway, followed by heme metabolism, metabolism of xenobiotics by Cytochrome P450 and O-glycan biosynthesis. Unexpectedly the key eosinophil chemokine Eotaxin-1/CCL11 was found to be up-regulated when NRF2 was inhibited and down-regulated when KEAP1 was inhibited. This transcriptional regulation leads to modulation of Eotaxin-1 secretion from human lung fibroblasts under basal and inflammatory conditions, and is specific to Eotaxin-1 as NRF2 or KEAP1 knockdown had no effect on the secretion of a set of other chemokines and cytokines. Furthermore, the known NRF2 small molecule activators CDDO and Sulphoraphane can also dose dependently inhibit Eotaxin-1 release from human lung fibroblasts.

Conclusions

These data uncover a previously unknown role for NRF2 in regulating Eotaxin-1 expression and further the mechanistic understanding of this pathway in modulating inflammatory lung disease.

Diagnostic value of exhaled carbon monoxide as an early marker of exacerbation in children with chronic lung diseases

Chronic airways infection and inflammation are leading causes of morbidity and mortality in chronic lung diseases (CLD). Pulmonary exacerbations are major causes of morbidity in CLD. Exhaled carbon monoxide (eCO) is a product of endogenous metabolic processes whose presence in exhaled breath is considered an index of inflammatory processes. Objective. To evaluate carbon monoxide (eCO) as inflammatory marker for early detection of acute exacerbation in CLD. Methods. Case control study included 40 children with CLD (twenty in exacerbation, group I and twenty in quiescent period, group II) recruited from the Chest Clinic, Children's Hospital, Ain Shams University. Twenty apparently healthy children were included as controls (group III). Results. Patients' mean age was 9.98 ± 3.29 years: 24 (60%) males and 16 (40%) females. The mean eCO level among patients during exacerbation was 5.35 ± 1.35 (ppm) compared to 2.65 ± 0.49 (ppm) in quiescent stage and 1.30 ± 0.47 (ppm) in controls. eCO cutoff value discriminating cases and control was 1.5 (ppm) (sensitivity; 100% and specificity 70%) and cutoff value discriminating group I from group II was 3 (ppm) (sensitivity: 100% and specificity: 100%). Conclusion. Exhaled CO can be considered a noninvasive early marker of acute exacerbation of CLD.

Breath biomarkers in diagnosis of pulmonary diseases

Breath analysis provides a convenient and simple alternative to traditional specimen testing in clinical laboratory diagnosis. As such, substantial research has been devoted to the analysis and identification of breath biomarkers. Development of new analytes enhances the desirability of breath analysis especially for patients who monitor daily biochemical parameters. Elucidating the physiologic significance of volatile substances in breath is essential for clinical use. This review describes the use of breath biomarkers in diagnosis of asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), lung cancer, as well as other pulmonary diseases. A number of breath biomarkers in lung pathophysiology will be described including nitric oxide (NO), carbon monoxide (CO), hydrogen peroxide (H₂O₂) and other hydrocarbons.

Assessment of airway inflammation in chronic obstructive pulmonary disease: Biomarkers in exhaled breath condensate

Airway inflammation plays a central role in the pathophysiology of chronic obstructive pulmonary disease. Exposure to cigarette smoke induces the recruitment of inflammatory cells in the airways, which in turn produces various cytokines, chemokines, proteases and pro-inflammatory mediators leading ultimately to increased oxidative stress, a protease/anti-protease imbalance and progressive lung tissue injury. Biomarkers may be useful in monitoring airway inflammation and oxidative stress, defining different phenotypes of the disease and evaluating the response of therapies. Exhaled breath condensate collection is a simple and completely non-invasive method of sampling the lower respiratory tract in humans. Exhaled breath condensate may be a rich source of pulmonary biomarkers including hydrogen peroxide, cytokines, metabolites of the arachidonic acid, nitric oxides and the pH. However, the concentration of these biomarkers is often very low, which may cause several problems in their detection. The clinical applicability of exhaled breath condensate biomarkers cannot be assessed until methods of sample collection and analysis have been standardized. Orv. Hetil., 2012, 153, 843–851.

Inflammation, chronic obstructive pulmonary disease and aging

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is characterized by an abnormal persistent inflammatory response to noxious environmental stimuli, particularly cigarette smoke. The determinants of the dysregulated immune responses, which play a role both in the onset and continuation of COPD, are largely unknown. We examined several molecular mechanisms regulating the inflammatory pathway, such as cytokine polymorphisms, miRNA expression, and DNA methylation in COPD and aging, with the aim to provide evidence supporting the view that aging of the immune system may predispose to COPD.

RECENT FINDINGS

The incidence of COPD increases with age. The pathogenesis of the disease is linked to a chronic inflammation and involves the recruitment and regulation of innate and adaptive immune cells. A chronic systemic inflammation characterizes aging and has been correlated with many diseases, most of them age-related.

SUMMARY

COPD and aging are associated with significant dysregulation of the immune system that leads to a chronic inflammatory response. The similar molecular mechanisms and the common genetic signature shared by COPD and aging suggest that immunosenescence may contribute to the development of COPD.

Alpha-1 antitrypsin is elevated in exhaled breath condensate and serum in exacerbated COPD patients

BACKGROUND

Exacerbations of chronic obstructive pulmonary disease (COPD) significantly contribute to COPD-related morbidity. Diagnosis of COPD exacerbations may be improved by analyzing biomarkers such as alpha-1 antitrypsin (AAT). AAT is an acute-phase protein and inhibitor of neutrophil elastase. Deficiency of AAT may result in early-onset respiratory symptoms. Measurement of exhaled breath condensate (EBC) is a noninvasive method to investigate biomarkers present in the epithelial lining fluid, such as AAT.

OBJECTIVE

To investigate whether AAT can be detected and quantified in EBC and to compare AAT levels in the EBC of healthy controls, patients with COPD, and during exacerbations of COPD.

METHODS

EBC from 10 healthy controls, 17 subjects with COPD, and 18 subjects with exacerbations of COPD was collected with the RTube™ device. AAT from EBC and serum were quantified by ELISA.

RESULTS

AAT in EBC was detectable in every individual. Patients with exacerbations of COPD had significantly increased AAT values (mean, 514.33 pg/mL, [SD 279.41 ]) compared with healthy controls (mean, 251.32 pg/mL, [SD 44.71]) and stable COPD patients (mean, 242.01 pg/mL [SD 65.74]) (P=0.0003; P=0.00003). EBC AAT showed only a correlation trend with serum AAT (r=0.3, P=0.054).

CONCLUSIONS

AAT in EBC was detectable and quantifiable. AAT measured in EBC was significantly increased during exacerbations of COPD and can potentially be used as a biomarker in exacerbations.

Expression of urease by Haemophilus influenzae during human respiratory tract infection and role in survival in an acid environment

Background

Nontypeable Haemophilus influenzae is a common cause of otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Prior studies have shown that H. influenzae expresses abundant urease during growth in the middle ear of the chinchilla and in pooled human sputum, suggesting that expression of urease is important for colonization and infection in the hostile environments of the middle ear and in the airways in adults. Virtually nothing else is known about the urease of H. influenzae, which was characterized in the present study.

Results

Analysis by reverse transcriptase PCR revealed that the ure gene cluster is expressed as a single transcript. Knockout mutants of a urease structural gene (ureC) and of the entire ure operon demonstrated no detectable urease activity indicating that this operon is the only one encoding an active urease. The ure operon is present in all strains tested, including clinical isolates from otitis media and COPD. Urease activity decreased as nitrogen availability increased. To test the hypothesis that urease is expressed during human infection, purified recombinant urease C was used in ELISA with pre acquisition and post infection serum from adults with COPD who experienced infections caused by H. influenzae. A total of 28% of patients developed new antibodies following infection indicating that H. influenzae expresses urease during airway infection. Bacterial viability assays performed at varying pH indicate that urease mediates survival of H. influenzae in an acid environment.

Conclusions

The H. influenzae genome contains a single urease operon that mediates urease expression and that is present in all clinical isolates tested. Nitrogen availability is a determinant of urease expression. H. influenzae expresses urease during human respiratory tract infection and urease is a target of the human antibody response. Expression of urease enhances viability in an acid environment. Taken together, these observations suggest that urease is important for survival and replication of H. influenzae in the human respiratory tract.

The role of TLRs in neutrophil activation

Neutrophils are key innate immune effector cells that are rapidly recruited to sites of infection and inflammation to provide early defence against invading microorganisms. This function is facilitated by the expression of Toll-like receptor (TLR) family members by neutrophils, allowing the recognition of an extensive repertoire of pathogen-associated molecular patterns (PAMPs) and thus triggering the response to invading pathogens. TLR activation leads to important cellular processes including reactive oxygen species (ROS) generation, cytokine production and increased survival, all of which can contribute to the pathogenesis of chronic inflammation when signalling becomes dysregulated. In turn, inflammation and tissue injury results in the release of endogenous TLR ligands, known as damage-associated molecular patterns (DAMPs), which are a rapidly growing class of potent inflammatory stimuli. DAMPs act in an autocrine manner, alerting the host of damage, but can also amplify inflammation leading to further tissue damage. This review highlights recent literature on neutrophil TLR function and regulation during disease, and provides an overview of the recently emerging area of neutrophil responses to DAMPs.

Breath analysis of hydrogen peroxide as a diagnostic tool

The potential diagnostic significance of exhaled hydrogen peroxide (H(2)O(2)) in pulmonary and systemic disorders has received considerable interest over the last few decades. Despite large physiologic variability and low specificity, airway H(2)O(2) generation has been found to be consistently increased by inflammatory conditions. Furthermore, the level of exhaled H(2)O(2) has been associated with efficacy of treatment in various pulmonary diseases. To evaluate this potential biomarker, detection methods including standardization protocols have been developed. Despite these advances, more comprehensive and controlled studies are required. In this manuscript we review progress to date in the analytical measurement of exhaled H(2)O(2) and speculate on its potential clinical significance as a diagnostic tool.

Changes in six-minute walking distance during pulmonary rehabilitation in patients with COPD and in healthy subjects

Background:

The six-minute walking distance (6MWD) test has demonstrated validity and reliability to assess changes in functional capacity following pulmonary rehabilitation in patients with chronic obstructive lung disease. However, no attempt has been made to establish an iterative measurement of 6MWD during the overall period of pulmonary rehabilitation. Therefore, the aim of this study was to evaluate the impact of a twelve-week rehabilitation program on the iterative weekly measurement of 6MWD in chronic obstructive pulmonary disease (COPD) patients and healthy subjects.

Methods:

Twenty-six patients with COPD and nine age-matched healthy subjects were studied. Measurements were taken at baseline and after twelve weeks except for the 6MWD. The exercise measurements included a six-minute walking test (6MWT) and an incremental exercise test. Oxygen saturation, heart rate, and dyspnea will be monitored during all these tests.

Results:

At baseline there were significant differences between groups, except in age, body mass index, and oxygen saturation. After 12 weeks, there was no significant change in lung function in patients with COPD and healthy subjects. The 6MWD, peak oxygen uptake V̇O_2peak and anaerobic threshold increased significantly after training in both groups (P < 0.01). The averaged trace of the 6MWD of patients with COPD and healthy subjects was followed-up respectively by a logarithmic and linear fitting. 6MWD showed a plateau after eight weeks in patients with COPD, however, it increased continually overall in healthy subjects.

Conclusion:

Both patients with COPD and healthy subjects demonstrated functional responses to training but with somewhat different patterns in quality of the improvement of the 6MWD.

Documentation of impaired coronary blood flow in chronic obstructive pulmonary disease patients

BACKGROUND

In the current study, the effects of moderate to severe chronic obstructive pulmonary disease (COPD) on coronary blood flow in patients with angiographically proven normal coronary arteries was evaluated.

METHODS AND RESULTS

A total of 85 patients with moderate to severe COPD and 39 age- and sex-matched control partcipants, who underwent diagnostic coronary angiography and found to have normal epicardial coronary angiogram constituted the COPD and control groups, respectively. The 2 groups were compared for Thrombolysis In Myocardial Infarction (TIMI) frame counts in each major coronary artery. The TIMI frame count of the COPD group was significantly higher than that of control group for all 3 major individual coronary arteries: left anterior descending (corrected), 37+/-13 vs 20+/-4; right coronary artery, 32+/-14 vs 21+/-4; and left circumflex artery, 34+/-12 vs 20+/-5, (P<0.001 for all). In addition, TIMI frame counts in individual coronary arteries were found to be positively correlated with forced expiratory volume 1 s percent, serum high sensitive C-reactive protein and fibrinogen concentrations, in the COPD group.

CONCLUSIONS

Our findings suggest that an increased slow coronary flow might be a manifestation of harmful effects of COPD on the coronary circulation, regardless of the underlying mechanism.

Increased H2O2 level in exhaled breath condensate in primary breast cancer patients

PURPOSE

This study was designed to assess exhaled hydrogen peroxide (H(2)O(2)), blood serum antioxidant capacity, and tumor necrosis factor-alpha (TNFalpha) in primary breast cancer (PBC).

METHODS

The study included 34 consecutive, non-smoking PBC patients (aged 62.5 +/- 13.5 at surgery) prior to the treatments, qualified for modified radical mastectomy and not undergoing any adjuvant systemic therapy, and 33 healthy controls. The post surgery pathological assessment included tissue expression of estrogen (ER) and progesterone (PR) receptors, and epidermal growth factor receptor type 2 (HER-2/neu). Exhaled H(2)O(2) was determined fluorometrically in the exhaled breath condensate (EBC). Blood serum antioxidant capacity and TNFalpha levels were assessed with ferric reducing ability of plasma (FRAP) and ELISA immunoassay, respectively.

RESULTS

In PBC patients, 10 ER, 11 PR, and 9 HER-2/neu positive tumors were identified and HER-2/neu score was 2+ in 20% of all tumors. Median (Me) H(2)O(2) was increased up to 0.44 microM (interquartile range IR: 0.20-1.25 microM) compared with healthy control of 0.36 microM (IR: 0.12-0.48 microM; p < 0.05). The H(2)O(2) concentration in EBC was significantly correlated (tau = 0.27; p = 0.03) and increased in cases with nodal metastases (n = 12; p = 0.04). Serum TNFalpha was increased up to 51.7 +/- 21.0 pg/ml compared with controls 17.2 +/- 3.65 pg/ml (p < 0.05). FRAP was increased to 1.41 +/- 0.37 mM Fe(2+) compared with control 1.19 +/- 0.17 mM Fe(2+); (p = 0.006).

CONCLUSIONS

This is the first study to demonstrate increased H(2)O(2) in exhaled breath condensate in patients with localized breast malignancy and its relation with clinical severity.

O papel do estresse oxidativo na DPOC: conceitos atuais e perspectivas

A DPOC é uma causa importante de morbidade e mortalidade em escala global. As manifestações clínicas e funcionais da DPOC resultam de danos pulmonares provocados por um conjunto de mecanismos, incluindo o estresse oxidativo, a inflamação, o desequilíbrio do sistema protease-antiprotease e a apoptose. O estresse oxidativo é central na gênese da DPOC, pois além de provocar dano direto às estruturas pulmonares, amplifica os demais mecanismos. Os eventos celulares e moleculares responsáveis pelo dano pulmonar antecedem em muito a expressão clínica e funcional da DPOC. Os broncodilatadores, principais drogas empregadas atualmente no tratamento da DPOC, não são eficazes em reduzir a progressão da doença. Avanços na compreensão da patogênese da DPOC aliados a esforços renovados na pesquisa básica e clínica deverão permitir sua detecção na fase pré-clínica e possibilitar um monitoramento mais adequado de sua atividade, além de permitir a introdução de novas modalidades de agentes terapêuticos capazes de impedir eficazmente sua progressão.

Metallic elements in exhaled breath condensate and serum of patients with exacerbation of chronic obstructive pulmonary disease

Biomarkers in exacerbated chronic obstructive pulmonary disease may be useful in aiding diagnosis, defining specific phenotypes of disease, monitoring the disease and evaluating the effects of drugs. The aim of this study was the characterization of metallic elements in exhaled breath condensate and serum as novel biomarkers of exposure and susceptibility in exacerbated chronic obstructive pulmonary disease using reference analytical techniques. C-Reactive protein and procalcitonin were assessed as previously validated diagnostic and prognostic biomarkers which have been associated with disease exacerbation, thus useful as a basis of comparison with metal levels. Exhaled breath condensate and serum were obtained in 28 patients at the beginning of an episode of disease exacerbation and when they recovered. Trace elements and toxic metals were measured by inductively coupled plasma-mass spectrometry. Serum biomarkers were measured by immunoassay. Exhaled manganese and magnesium levels were influenced by exacerbation of chronic obstructive pulmonary disease, an increase in their concentrations--respectively by 20 and 50%--being observed at exacerbation in comparison with values obtained at recovery; serum elemental composition was not modified by exacerbation; serum levels of C-reactive protein and procalcitonin at exacerbation were higher than values at recovery. In outpatients who experienced a mild-moderate chronic obstructive pulmonary disease exacerbation, manganese and magnesium levels in exhaled breath condensate are elevated at admission in comparison with values at recovery, whereas no other changes were observed in metallic elements at both the pulmonary and systemic level.

Oxidants and the pathogenesis of lung diseases

The increasing number of population-based and epidemiologic associations between oxidant pollutant exposures and cardiopulmonary disease exacerbation, decrements in pulmonary function, and mortality underscores the important detrimental effects of oxidants on public health. Because inhaled oxidants initiate a number of pathologic processes, including inflammation of the airways, which may contribute to the pathogenesis and/or exacerbation of airways disease, it is critical to understand the mechanisms through which exogenous and endogenous oxidants interact with molecules in the cells, tissues, and epithelial lining fluid of the lung. Furthermore, it is clear that interindividual variation in response to a given exposure also exists across an individual lifetime. Because of the potential impact that oxidant exposures may have on reproductive outcomes and infant, child, and adult health, identification of the intrinsic and extrinsic factors that may influence susceptibility to oxidants remains an important issue. In this review, we discuss mechanisms of oxidant stress in the lung, the role of oxidants in lung disease pathogenesis and exacerbation (eg, asthma, chronic obstructive pulmonary disease, and acute respiratory distress syndrome), and the potential risk factors (eg, age, genetics) for enhanced susceptibility to oxidant-induced disease.

Airways inflammation and treatment during acute exacerbations of COPD

INTRODUCTION

Inflammation is a core feature of acute chronic obstructive pulmonary disease (COPD) exacerbations. It is important to focus on inflammation since it gives insight into the pathological changes causing an exacerbation, thereby possibly providing directions for future therapies which modify inflammation.

OBJECTIVES

To provide a cell-by-cell overview of the inflammatory processes during COPD exacerbations. To evaluate cell activation, and cytokine production, cellular interactions, damaging effects of inflammatory mediators to tissue, and the relation to symptoms at the onset of COPD exacerbations. To speculate on future therapeutic options to modify inflammation during COPD exacerbations.

RESULTS

During COPD exacerbations, there is increased airway wall inflammation, with pathophysiological influx of eosinophils, neutrophils, and lymphocytes. Although links have been suggested between the increase in eosinophils and lymphocytes and a viral etiology of the exacerbation, and between the increase in neutrophils and a bacterial aetiology, these increases in both inflammatory cell types are not limited to the respective aetiologies and the underlying mechanisms remain elusive.

CONCLUSION

Further research is required to fully understand the inflammatory mechanisms in the onset and development of COPD exacerbations. This might make inflammatory pathway-specific intervention possible, resulting in a more effective treatment of COPD exacerbations with fewer side effects.

A sensitive chemiluminescence method for the determination of H2O2 in exhaled breath condensate

In this paper, a novel flow injection chemiluminescence (FI-CL) method is proposed for the determination of picomolar L(-1) levels of hydrogen peroxide (H(2)O(2)) in exhaled breath condensate (EBC). This method is based on the oxidation of a low concentration of luminol (10(-7) M) by H(2)O(2) at a low concentration level (< 10(-8) M) in an alkaline medium catalyzed by a complex, K(5)[Cu(HIO(6))(2)] (DPC), which is not interfered by other metal ions or horseradish peroxidase (HRP). Under the optimum conditions, H(2)O(2) was determined over the range of 1.0 x 10(-10) to 1.0 x 10(-8) mol L(-1) with a detection limit of (3sigma) of 4.1 x 10(-11) mol L(-1). The relative standard deviation (RSD) was 3.2% for 5 nmol L(-1) H(2)O(2) (n = 7). The proposed method offers the advantages of ultra-sensitivity, selectivity, simplicity and rapidity for H(2)O(2) determination. It was successfully applied to directly determine trace amounts of H(2)O(2) (nmol L(-1)) in human's EBC of both rheum and healthy volunteers. A statistically significant difference was found between patients with rheum (n = 11) and control subjects without rheum (n = 11).

Oxidative stress in chronic obstructive pulmonary disease patients submitted to a rehabilitation program

Pulmonary rehabilitation (PR) improves physical capacity and health quality in patients with chronic obstructive pulmonary disease (COPD). However, the effect of exercise on oxidative stress markers in COPD patients is only partially known. This study was designed to evaluate the oxidative stress response to long-term exercise in patients with COPD enrolled in a PR program. Fifteen COPD patients (FEV1 < 60%), age between 50 and 60 years, ex-smokers, were separated in two groups: exercise-trained (n=8) and sedentary group (n=7). Exercise consisted of an 8-week conditioning program using a cycle ergometer (three times a week, 1h session). An endurance test (60% of maximal load in an incremental cycle test) was performed before and after PR. Blood samples were obtained at baseline and immediately after each endurance test. We measured the index of lipid peroxidation, thiobarbituric acid reactive species (TBARS), total radical-trapping antioxidant parameter (TRAP) and xanthine oxidase (XO) activity. TRAP was significantly different between the exercise-trained group and sedentary group of COPD patients. Baseline TBARS values were increased after the exercise training program but decreased after the endurance test. XO decrease after effort in the trained and untrained groups. The results suggest that patients with COPD are characterized by increased systemic and pulmonary oxidative stress markers both at rest as well as induced by cardiopulmonary exercise test and that PR program was associated with decreased systemic exercise-induced oxidative damage.

[Hydrogen peroxide in the troposphere]

The past few decades saw a rising interest in the role of hydrogen peroxide (H2O2) in atmospheric chemistry and its contribution to the formation of free radicals. Free radicals (oxidants) are formed by photochemical reactions between ozone and H2O2. Free radicals formed within cells can oxidise biomolecules, and this may lead to cell death and tissue injury. For this reason, free radicals are believed to cause more than 100 diseases. H2O2 has been suggested as a better indicator of atmospheric oxidation capacity than ozone. Atmospheric H2O2 can appear in the gas phase or in the aqueous phase. It shows typical diurnal and seasonal variations. However, measurements of H2O2 with expensive and sophisticated equipment are rare and limited to but a few sites in the world. Measurements in Greenland ice cores showed that H2O2 concentrations increased over the last 200 years and most of the increase has occurred over the last 20 years. Evaluations show that concentrations will still rise as a result of decreasing SO2 emission. H2O2 measurements have not been carried out in Croatia until now, and, accompanied by the existing longterm measurements of ozone and nitrogen oxides, they will provide an idea of the oxidative capacity of the atmosphere and its influence on oxidative stress.

Systemic inflammation and systemic oxidative stress in patients with acute exacerbations of COPD

BACKGROUND

In patients with chronic obstructive pulmonary disease (COPD), the inflammatory processes and oxidative stress are closely linked in the lung compartment. However, the relationships between systemic inflammation and parameters of oxidative stress in the systemic circulation during acute exacerbations of COPD remain to be explored.

OBJECTIVE

To analyze relationships between erythrocytic glutathione peroxidase (GPx), a marker of systemic oxidative stress, and parameters reflecting systemic inflammation, such as circulating neutrophils, C-reactive protein (CRP), and interleukin (IL)-6, in patients with acute exacerbations of COPD.

PATIENTS AND METHODS

We measured erythrocytic GPx activity, circulating neutrophil count, and serum high-sensitivity (hs) CRP and IL-6 in 177 patients admitted to the hospital due to an acute exacerbation of COPD (91 males, mean age 66.8+/-0.9 years, mean FEV1 45.3+/-1.3% predicted).

RESULTS

From GOLD Stage II to Stage III and IV, erythrocytic GPx activity significantly decreased [mean+/-SEM: from 44.3+/-1.7 U/g Hb to 40.8+/-1.1 U/g Hb and to 38.4+/-1.5 U/g Hb, p = 0.037], while serum hsCRP increased [median (25th, 75th percentile): from 9.6 (3.0, 23.0) mg/l to 23.3 (6.4, 46.8) mg/l, and to 26.7 (6.5, 117.2) mg/l, p = 0.004]. Erythrocytic GPx activity was significantly inversely related to both, log neutrophil count (r = -0.219, p = 0.003) and log hsCRP (r = -0.199, p = 0.008).

CONCLUSIONS

Our study suggests an association between systemic inflammation and systemic oxidative stress reflected by erythrocytic GPx in patients with acute exacerbations of COPD.

Sleep apnea is associated with bronchial inflammation and continuous positive airway pressure-induced airway hyperresponsiveness

BACKGROUND

Obstructive sleep apnea syndrome (OSA) is associated with systemic and upper airway inflammation. Pharyngeal inflammation has a potential role in upper airway collapse, whereas systemic inflammation relates to cardiovascular morbidity. However, the presence of an inflammatory involvement of lower airway has been poorly investigated.

OBJECTIVE

The aim of the study was to demonstrate an inflammatory process at the bronchial level in patients with OSA and to analyze effects of continuous positive airway pressure (CPAP) application and humidification on bronchial mucosa.

METHODS

The study was conducted by using sequential induced sputum for cell analysis and IL-8 production, nitric oxide exhalation measurement, and methacholine challenge before and after CPAP.

RESULTS

Bronchial neutrophilia and a high IL-8 concentration were observed in untreated OSA compared with controls (75% +/- 20% vs 43% +/- 12%, P < .05; and 25.02 +/- 9.43 ng/mL vs 8.6 +/- 3.7 ng/mL, P < .001, respectively). IL-8 in sputum supernatant was correlated to apnea hypopnea index (P < .01; r = 0.81). After 1 month of CPAP, this inflammatory pattern remained unchanged, and an increase in airway hyperresponsiveness (AHR) was observed (P < .001).

CONCLUSION

Obstructive sleep apnea syndrome is associated with bronchial inflammation. Our data demonstrate CPAP effect on the development of AHR, possibly facilitated by the pre-existing inflammation. Both issues should be evaluated during long-term CPAP use.

CLINICAL IMPLICATIONS

Results showing a spontaneous bronchial inflammation in OSA and the development of a CPAP-related AHR require a long-term follow-up to evaluate consequences on chronic bronchial obstruction.

Systemic antioxidant defences during acute exacerbation of chronic obstructive pulmonary disease

OBJECTIVE AND BACKGROUND

Existence of an increased oxidative stress has been confirmed in patients with acute exacerbation of COPD. This study aims to examine the extent and time-course of antioxidant defence in patients with an acute exacerbation of COPD in comparison with stable patients.

METHODS

Twelve patients with acute exacerbation were studied at admission, and then 24 h and 48 h following admission and at discharge. The antioxidants assessed were the endogenous antioxidants: glutathione peroxidase, superoxide dismutase, oxidized and reduced glutathione, albumin and exogenous antioxidants: alpha-tocopherol and retinol. Trolox equivalent antioxidant capacity as a marker of antioxidant status was also measured.

RESULTS

There was an increase in glutathione peroxidase and superoxide dismutase 48 h after admission (P<0.05). Alpha-tocopherol was the lowest 24 h after admission and increased significantly at discharge (P<0.05).

CONCLUSIONS

There is an increase in antioxidant defence during acute exacerbation of COPD reaching a maximum at 48 h after admission. This rise in the antioxidant defence is not sufficient to prevent depletion of non-enzymatic antioxidants such as alpha-tocopherol.

Markers of airway inflammation in primary ciliary dyskinesia studied using exhaled breath condensate

Macroscopically, the airways in primary ciliary dyskinesia (PCD) are inflamed and infected, and the eventual result is bronchiectasis. The measurement of noninvasive markers of inflammation in PCD may allow determination of mechanisms of tissue damage, and even allow monitoring of therapy. The aim of this study was to measure in exhaled breath condensate (EBC) of children with PCD the concentrations of the neutrophil chemoattractants leukotriene (LT) B4 and interleukin (IL)-8 and the marker of oxidative stress 8-isoprostane (8-IP), and to try determining whether these markers can be used to assess mechanisms of airway inflammation in these patients. Concentrations of LTB4, IL-8, and 8-IP in the EBC of 23 PCD and 11 age-matched healthy children were measured using an enzyme immunoassay (EIA). The children also performed spirometry and underwent sputum induction, the latter for differential cell count. The concentrations of 8-IP in EBC of children with stable PCD were significantly increased compared to normal controls (median, 7.8 pg/ml vs. 3.1 pg/ml; P = 0.004). There was no difference in the median concentrations of EBC LTB4 between PCD subjects and healthy controls (28 pg/ml vs. 28 pg/ml; P = 0.5). IL-8 levels were below the detection limit of the assay, and were not analyzed further. There was no correlation between concentrations of either 8-IP or LTB(4) in EBC and forced expired volume in 1 sec in PCD children. Sputum induction was successful in 83% of the subjects; the median induced sputum neutrophil count was 69% (interquartile range, 59.3-73.6). No significant correlation was found between sputum neutrophils and either EBC 8-IP or LTB4 concentrations in PCD children. This study showed that oxidative stress, as reflected by increased exhaled 8-IP concentration, is increased in PCD children. The mechanism of airway neutrophilia is unclear, but is unlikely to be related to increased production of LTB4, at least in stable PCD patients.