The Role of Exhaled Breath Condensate in Chronic Inflammatory and Neoplastic Diseases of the Respiratory Tract

Asthma and chronic obstructive pulmonary disease (COPD) are among the most common chronic respiratory diseases. Chronic inflammation of the airways leads to an increased production of inflammatory markers by the effector cells of the respiratory tract and lung tissue. These biomarkers allow the assessment of physiological and pathological processes and responses to therapeutic interventions. Lung cancer, which is characterized by high mortality, is one of the most frequently diagnosed cancers worldwide. Current screening methods and tissue biopsies have limitations that highlight the need for rapid diagnosis, patient differentiation, and effective management and monitoring. One promising non-invasive diagnostic method for respiratory diseases is the assessment of exhaled breath condensate (EBC). EBC contains a mixture of volatile and non-volatile biomarkers such as cytokines, leukotrienes, oxidative stress markers, and molecular biomarkers, providing significant information about inflammatory and neoplastic states in the lungs. This article summarizes the research on the application and development of EBC assessment in diagnosing and monitoring respiratory diseases, focusing on asthma, COPD, and lung cancer. The process of collecting condensate, potential issues, and selected groups of markers for detailed disease assessment in the future are discussed. Further research may contribute to the development of more precise and personalized diagnostic and treatment methods.

Biomarkers in exhaled breath condensate as fingerprints of asthma, chronic obstructive pulmonary disease and asthma-chronic obstructive pulmonary disease overlap: a critical review

Asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap are the third leading cause of mortality around the world. They share some common features, which can lead to misdiagnosis. To properly manage these conditions, reliable markers for early and accurate diagnosis are needed. Over the past 20 years, many molecules have been investigated in the exhaled breath condensate to better understand inflammation pathways and mechanisms related to these disorders. Recently, more advanced techniques, such as sensitive metabolomic and proteomic profiling, have been used to obtain a more comprehensive understanding. This article reviews the use of targeted and untargeted metabolomic methodology to study asthma, COPD and asthma-COPD overlap.

Efficacy of statin therapy in chronic obstructive pulmonary disease: a systematic review and meta-analysis from 2008-2019

INTRODUCTION

Statins produce significant hypolipidemic effects and reduce C-reactive protein (CRP) in patients with chronic obstructive pulmonary disease (COPD). It has been reported that statins did not prevent the acute exacerbation of COPD or improve clinical outcomes. Therefore, we analyzed the actual therapeutic effects of statins on COPD therapy during long-term clinical trials.

EVIDENCE ACQUISITION

Relevant studies were retrieved from various databases from 2008 to 2019. For each study, Odds Ratios (ORs), mean difference (MD) and 95% confidence interval (95% CI) were assessed.

EVIDENCE SYNTHESIS

Thirty-two studies were retrieved with 3137 patients receiving statin therapy and 3140 controls. Satins significantly increased exercise capacity (47.21, 95% CI: 20.79-73.63), lung FEV1 (4.02, 95% CI: 2.28-5.75), forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) (3.56, 95% CI: 2.01-5.10) and high-density lipoproteins (HDL) (5.573, 95% CI: 1.74-9.41). In addition, statins downregulated CRP function (W=-1.60, 95% CI: -2.45-0.76), IL-6 (-3.35, 95% CI: -4.94 to -1.76), St George's breath questionnaire (SGRQ) scores (-9.96, 95% CI: -12.83 to -7.10), COPD assessment test (CAT) (-3.49, 95% CI: -4.70 to 2.29) and systolic blood pressure (-4.992, 95% CI: -5.17 to -4.818). Total cholesterol (TC) (-37.84, 95% CI: -46.10 to 29.58) low-density lipoproteins (LDL) (-26.601, 95% CI: -26.688 to 26.514) and triglycerides (TG) (-42.914, 95% CI: -61.809 to 24.02) were also decreased.

CONCLUSIONS

Clinical trials conducted over a 10-year period revealed beneficial advantages of statin therapy in COPD patients, permitting increased exercise capacity, FEV1/FVC and HDL. In addition, CRP, IL-6, systolic blood pressure, SGRQ scores and CAT were significantly decreased as well as lipid levels.

Inhaled Medications in Chronic Respiratory Diseases: Analysis of Real-Life Use in Puglia (Apulia), Italy

BACKGROUND

Chronic respiratory diseases (CRDs) are common diseases with a heterogeneous distribution worldwide. Due to their impact on disability, weight assistance and pharmaceutical spending, they represent an important global burden for national health systems. However, few studies have investigated the use and consumption of inhaled drugs in real life in patients with CRDs.

OBJECTIVE

This study aimed to investigate the real-life consumption of health care resources of main CRDs through an analysis of the administrative databases of the local health authority (ASL) in the Puglia region (Italy).

METHODS

The present study is an observational study that longitudinally reviewed the administrative and health databases associated with patients' consumption of health resources between 2017 and 2018.

RESULTS

The first important finding is a marked underestimation of the true incidence of CRDs despite the search for disease-specific exemption codes. Another important result is that the real-life consumption of inhaled drugs among these patients is well below the minimum acceptable values for adherence. The most commonly used inhaled drugs, for which at least one pack was withdrawn, were inhaled steroids (61.6%), followed by the ICS/LABA combination (43.7%) and LABAs (32.4%). However, less than one-third of patients (31%) withdrew at least three packages of ICS or ICS/LABA during the year, while the percentage was reduced to less than 15% for other combinations. Another alarming finding is that only 8.4% of patients taking CRDs drugs reported at least one spirometry during the study period.

CONCLUSIONS

The wide availability of computerized systems may be an important tool for increasing therapeutic adherence and optimizing the resources of health systems in the diagnosis, treatment and management of patients with CRDs.

Understanding the role of smoking and chronic excess alcohol consumption on reduced caloric intake and the development of sarcopenia

This narrative review provides mechanistic insight into the biological link between smoking and/or chronic excess alcohol consumption, and increased risk of developing sarcopenia. Although the combination of excessive alcohol consumption and smoking is often associated with ectopic adipose deposition, this review is focused on the context of a reduced caloric intake (leading to energy deficit) that also may ensue due to either lifestyle habit. Smoking is a primary cause of periodontitis and chronic obstructive pulmonary disease that both induce swallowing difficulties, inhibit taste and mastication, and are associated with increased risk of muscle atrophy and mitochondrial dysfunction. Smoking may contribute to physical inactivity, energy deficit via reduced caloric intake, and increased systemic inflammation, all of which are factors known to suppress muscle protein synthesis rates. Moreover, chronic excess alcohol consumption may result in gut microbiota dysbiosis and autophagy-induced hyperammonemia, initiating the up-regulation of muscle protein breakdown and down-regulation of muscle protein synthesis via activation of myostatin, AMPK and REDD1, and deactivation of IGF-1. Future research is warranted to explore the link between oral healthcare management and personalised nutrition counselling in light of potential detrimental consequences of chronic smoking on musculoskeletal health outcomes in older adults. Experimental studies should investigate the impact of smoking and chronic excess alcohol consumption on the gut-brain axis, and explore biomarkers of smoking-induced oral disease progression. The implementation of behavioural change interventions and health policies regarding smoking and alcohol intake habits may mitigate the clinical and financial burden of sarcopenia on the healthcare system.

Effect of modified Total Body Recumbent Stepper training on exercise capacity and thioredoxin in COPD: a randomized clinical trial

Exercise intolerance is one of the major symptoms of chronic obstructive pulmonary disease (COPD). Exercise training can benefit COPD patients, but the underlying mechanism remains unclear. The modified Total Body Recumbent Stepper (TBRS, Nustep-T4) can benefit patients with stroke, spinal cord injury and amyotrophic lateral sclerosis. Nevertheless, the effect of TBRS training alone on pulmonary rehabilitation (PR) in COPD patients remains largely unknown. We aimed to explore the effect of TBRS training on exercise capacity and the thioredoxin system (TRXS) in COPD patients to provide a novel rehabilitation modality and new theoretical basis for PR of COPD patients. Ninety stable COPD patients were randomly divided into a control group (NC group) and a TBRS training group (TBRS group), with 45 cases in each group. Subjects in the TBRS training group were scheduled to undergo TBRS endurance training triweekly for 12 weeks under the guidance of a rehabilitation therapist. We assessed the primary outcome: exercise capacity (6-min walking distance, 6MWD); and secondary outcomes: perception of dyspnoea (mMRC, Borg), the COPD assessment test (CAT), the BODE index, pulmonary function, the number of acute exacerbations of COPD and oxidative stress (TRXS) at one-year follow-up. Compared with before the intervention and the control group, after the intervention, the TBRS training group, exhibited an increase in the 6MWD (from 366.92 ± 85.81 to 484.10 ± 71.90, 484.10 ± 71.90 vs 370.63 ± 79.87, P < 0.01), while the scores on the BORG, mMRC, BODE index, CAT, and the number of acute exacerbations of COPD were reduced, and the protein and mRNA expression levels of TRXS was significantly increased (P < 0.01). However, no differences were found in PF parameters in the comparison with before the intervention or between groups. TBRS training can effectively increase exercise capacity, while there are indications that it can alleviate COPD-related dyspnoea and reduce the number of acute exacerbations of COPD. Interestingly, long-term regular TBRS training may reduce oxidative stress associated with COPD to increase exercise capacity.

Serum interleukin-6 in chronic obstructive pulmonary disease patients and its relation to severity and acute exacerbation

Background and objectives

The role of interleukins in the severity and clinical profile of chronic obstructive pulmonary disease (COPD) is not known, but evidence supports the contribution of systemic inflammation to disease pathophysiology. This study evaluated the relationship of serum interleukin-6 (IL-6) to the severity and clinical parameters of COPD.

Aim of work

The aim of the work is to estimate the level of IL-6 in COPD patients and its relation to COPD severity and acute exacerbation.

Patients and method

We analyzed 45 COPD patients and 45 normal population as control. We estimate the IL-6 level by ELISA and correlate it with the severity and frequency of COPD exacerbation.

Results

In the current study, we noticed that IL-6 level was high in COPD patients and in those who experience frequent exacerbation. Also, IL-6 show a relation with the parameter of pulmonary function test; there is a statistically significant negative correlation with p-value < 0.05 between the level of IL-6 and the forced expired volume in 1 s/forced vital capacity (EFV1/FVC) among cases with COPD, which indicated that decrease in EFV/FVC will associate with the increase in IL-6 level.

Conclusions

The study revealed that serum IL-6 level elevated with increasing severity of airflow limitation in COPD patients, particularly in acute exacerbation phase. This increase was associated with a reduced quality of life and increased severity of hypoxemia.

Evaluation of selected IL6/STAT3 pathway molecules and miRNA expression in chronic obstructive pulmonary disease

COPD has been regarded as a global epidemic due to an increase in pollution and tobacco exposure. Therefore, the study of molecular mechanism as the basis for modern therapy is important. The aim of the study was the assessment of gene expression levels, IL-6, IL-6ST, PIAS3, STAT3, and miRNAs, miRNA-1, miRNA-106b, miRNA-155, in patients with COPD. Induced sputum as well as PBMC were collected from 40 patients clinically verified according to the GOLD 2021 (A-D) classification and from the control group (n = 20). The levels of gene and miRNA expression were analysed by qPCR. In induced sputum IL6 was significantly down-regulated in COPD group compared with control (p = 0.0008), while IL6ST were up-regulated (p = 0.05). The results were also statistically significant for STAT3 (p = 0.04) and miRNA-155 (p = 0.03) with higher expression in the current smokers compared to ex-smokers. Higher expression levels for IL6ST (p = 0.03) in COPD patients with the exacerbation history compared to COPD patients without the exacerbation history were noted. Compared induced sputum and PB lymphocytes we observed higher expression of IL6 (p = 0.0003), STAT3 (p = 0.000001) miRNA-106b (p = 0.000069 and miRNA-155 (p = 0.000016) in induced sputum with lower expression of PIAS3 (p = 0.006), IL6ST (p = 0.002) and miRNA-1 (p = 0.001). Differences in gene expression levels of the IL-6/IL6ST/STAT3 pathway and miRNA depending on the smoking status and classification of patients according to GOLD suggest the importance of these genes in the pathogenesis of COPD and may indicate their potential utility in monitoring the course of the disease.

Accelerated immunosenescence, oxidation and inflammation lead to a higher biological age in COPD patients

Chronic obstructive pulmonary disease (COPD) is characterised by inflammatory and oxidative alterations in the lung and extrapulmonary compartments, through involvement of the immune system. Several leukocyte functions are health markers and good predictors of longevity, and high pro-inflammatory and oxidative states are related to more aged profiles. Here, we aimed to investigate the aging rate in terms of immunosenescence in COPD men with respect to healthy age-matched controls. Several neutrophil (adherence, chemotaxis, phagocytosis, superoxide anion stimulated production) and lymphocyte (adherence, chemotaxis, lymphoproliferation, natural killer activity) functions, cytokine concentrations released in response to lipopolysaccharide (tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, IL-10) and redox parameters (intracellular glutathione content, basal superoxide anion level) were assessed in circulating leukocytes of men with moderate and severe stages of COPD, and compared to healthy age-matched volunteers. The biological age or aging rate in each participant was determined using the values of leukocyte functions. The results indicated impairment of immune functions in COPD patients, both in innate and adaptive immunity, and higher pro-inflammatory and oxidative states in peripheral leukocytes than controls. In general, these changes were more remarkable at the severe stage of airway obstruction. Importantly, COPD patients were found to be aging at a faster rate than age-matched healthy counterparts.

Novel pharmacological strategies to treat cognitive dysfunction in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major incurable global health burden and currently the 3rd largest cause of death in the world, with approximately 3.23 million deaths per year. Globally, the financial burden of COPD is approximately €82 billion per year and causes substantial morbidity and mortality. Importantly, much of the disease burden and health care utilisation in COPD is associated with the management of its comorbidities and viral and bacterial-induced acute exacerbations (AECOPD). Recent clinical studies have shown that cognitive dysfunction is present in up to 60% of people with COPD, with impairments in executive function, memory, and attention, impacting on important outcomes such as quality of life, hospitalisation and survival. The high prevalence of cognitive dysfunction in COPD may also help explain the insufficient adherence to therapeutic plans and strategies, thus worsening disease progression in people with COPD. However, the mechanisms underlying the impaired neuropathology and cognition in COPD remain largely unknown. In this review, we propose that the observed pulmonary oxidative burden and inflammatory response of people with COPD 'spills over' into the systemic circulation, resulting in damage to the brain and leading to cognitive dysfunction. As such, drugs targeting the lungs and comorbidities concurrently represent an exciting and unique therapeutic opportunity to treat COPD and cognitive impairments, which may lead to the production of novel targets to prevent and reverse the debilitating and life-threatening effects of cognitive dysfunction in COPD.

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.

Macromolecular biomarkers of chronic obstructive pulmonary disease in exhaled breath condensate

Biomarkers provide important diagnostic and prognostic information on heterogeneous diseases such as chronic obstructive pulmonary disease (COPD). However, finding a suitable specimen for clinical analysis of biomarkers for COPD is challenging. Exhaled breath condensate (EBC) sampling is noninvasive, rapid, cost-effective and easily repeatable. EBC sampling has also provided recent progress in the identification of biological macromolecules, such as lipids, proteins and DNA in EBC samples, which has increased its utility for clinical scientists. In this article, we review applications involving EBC sampling for the analysis of COPD biomarkers and discuss its future potential.

Reliability and Usefulness of Different Biomarkers of Oxidative Stress in Chronic Obstructive Pulmonary Disease

Introduction

Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by airflow limitation that is not fully reversible after inhaled bronchodilator use associated with an abnormal inflammatory condition. The biggest risk factor for COPD is cigarette smoking. The exposure to noxious chemicals contained within tobacco smoke is known to cause airway epithelial injury through oxidative stress, which in turn has the ability to elicit an inflammatory response. In fact, the disruption of the delicate balance between oxidant and antioxidant defenses leads to an oxidative burden that has long been held responsible to play a pivotal role in the pathogenesis of COPD. There are currently several biomarkers of oxidative stress in COPD that have been evaluated in a variety of biological samples. The aim of this review is to identify the best studied molecules by summarizing the key literature findings, thus shedding some light on the subject.

Methods

We searched for relevant case-control studies examining oxidative stress biomarkers in stable COPD, taking into account the analytical method of detection as an influence factor.

Results

Many oxidative stress biomarkers have been evaluated in several biological matrices, mostly in the blood. Some of them consistently differ between the cases and controls even when allowing different analytical methods of detection.

Conclusions

The present review provides an overview of the oxidative stress biomarkers that have been evaluated in patients with COPD, bringing focus on those molecules whose reliability has been confirmed by the use of different analytical methods.

Association between tumor necrosis factor-α and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background:

Patients diagnosed with chronic obstructive pulmonary disease (COPD) have increased risks for a series of physical and mental illnesses. Tumor necrosis factor-α (TNF-α) has been reported to participate in the development of COPD and its complications. However, the values of blood TNF-α level used in the diagnosis of COPD remains controversial. In view of this, we performed a systematic review and meta-analysis to evaluate the correlation between TNF-α level and COPD.

Methods:

We searched PubMed, Web of Science, Embase and CNKI up to May 2018. The selection criteria were set according to the PICOS framework. A random-effects model was then applied to evaluate the overall effect sizes by calculating standard mean difference (SMD) and its 95% confidence intervals (CIs).

Results:

A total of 40 articles containing 4189 COPD patients and 1676 healthy controls were included in this meta-analysis. The results indicated a significant increase in TNF-α level in the COPD group compared with the control group (SMD: 1.24, 95% CI: 0.78–1.71, p < 0.00001). According to the subgroup analyses, we noted that TNF-α level was associated with predicted first second of forced expiration (FEV₁) (%) and study region. However, no association between TNF-α level and COPD was found when the participants were nonsmokers, and the mean age was less than 60 years.

Conclusions:

Our results indicated that TNF-α level was increased in COPD patients when compared with healthy controls. Illness progression and a diagnosis of COPD might contribute to higher TNF-α levels. However, the underlying mechanism still remains unknown and needs further investigation.

The reviews of this paper are available via the supplemental material section.

Correlations Between Serum Decoy Receptor 3 and Airflow Limitation and Quality of Life in Male Patients with Stable Stage and Acute Exacerbation of COPD

PURPOSE

Serum decoy receptor 3 (DcR3) level increases in chronic inflammatory diseases. The present study aimed to examine serum DcR3 and IL-6 levels in male patients with stable chronic obstructive pulmonary disease (COPD) and acute exacerbation of the disease and correlations between these markers and airflow limitation.

METHODS

We measured serum DcR3 and IL-6 levels in 60 COPD patients [30 stable COPD (SCOPD), and 30 acute exacerbation of COPD (AECOPD)], and 30 control subjects and assessed their correlations with airflow limitation according to the COPD stage indicated by the global initiative for chronic obstructive pulmonary disease (GOLD) criteria, peripheral O₂ saturation (SpO₂), and COPD assessment test (CAT) score. We also tested associations between serum DcR3 levels and COPD patients' clinical parameters.

RESULTS

Both serum DcR3 and IL-6 levels increased with increasing severity of airflow limitation in SCOPD and AECOPD groups (P < 0.01 to 0.001). These markers also increased in patients with AECOPD compared with subjects in SCOPD group in GOLD stages III-IV (P < 0.05 to 0.001). In addition, there was a significant positive correlation between serum DcR3 level and IL-6, CAT score and smoking history (per year).

CONCLUSION

The study revealed that serum DcR3 level elevated with increasing severity of airflow limitation in male COPD patients, particularly in acute exacerbation phase. This increase was associated with a reduced quality of life and increased severity of hypoxia. These results suggest that DcR3 may be associated with the underlying pathophysiology of COPD in male patients.

Effects of dexmedetomidine on oxidative stress and inflammatory response in lungs during mechanical ventilation in COPD rats

Effects of dexmedetomidine (Dex) on oxidative stress and inflammatory response in lungs during mechanical ventilation in chronic obstructive pulmonary disease (COPD) rats were investigated. Eleven out of 38 SD rats were randomly selected as the blank control group, and the other 27 rats were subjected to modeling. After the modeling, 11 rats in the blank control group and 11 rats randomly selected from the model group received non-invasive test for lung function. Three rats from the blank control group and 3 rats from the model group were selected for hematoxylin and eosin (HE) staining to confirm successful modeling, and the other 24 rats were randomly divided into 3 groups, 8 rats in each group, including model control, Dex low-dose and Dex high-dose group. A COPD rat model was established by passive cigarette smoking and intratracheal instillation of lipopolysaccharide. Each group underwent mechanical ventilation for 2 h. The Dex low-dose group and Dex high-dose group were intravenously administered at 1.0 µg/kg/h and 5.0 µg/kg/h of Dex, and the other two groups received intravenous drip of the same amount of normal saline. Blood gas analysis was performed to calculate carbon dioxide partial pressure (PaCO₂), oxygen partial pressure (PaO₂) and blood pH. HE staining was performed to analyze pulmonary pathological features of COPD rat model. Serum inflammatory factors interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were detected by ELISA, and the levels of antioxidant enzymes superoxide dismutase 2 (SOD2) and catalase were analyzed by western blot analysis. After 28 days of modeling, TV, PEF, FEV0.3 and FEV0.3/FVC decreased significantly in the COPD model group. HE staining showed that in the model group, the alveolar cells became larger, the alveolar wall became thinner, and some alveolar walls were even broken. The lung lobule showed obvious cell degeneration, necrosis and shedding, and the interstitial inflammatory cell infiltration, suggesting that the COPD rat model was successfully established. After 2 h of mechanical ventilation and Dex intravenous infusion, PaCO₂ decreased, PaO₂ increased, and blood pH value increased (p<0.05). Inflammatory factors IL-8 and TNF-α decreased (p<0.05). Oxidative stress index MDA also decreased (p<0.05), antioxidant enzymes SOD2 and catalase increased (p<0.05). Dexmedetomidine can improve the oxidative stress response during mechanical ventilation in rats with COPD, and can reduce the inflammation of lung tissue, thus protecting the lung tissue of COPD rats.

Serum oxidative stress in patients with pulmonary Mycobacterium avium complex disease

Background

The mechanism of progressive airway destruction in incurable chronic infection of the lung – termed pulmonary Mycobacterium avium complex (pMAC) disease – is currently unknown. The involvement of oxidative stress in a variety of progressive chronic respiratory diseases has been previously reported. It has been hypothesized that oxidative stress may be involved in the progression of airway destruction in pMAC disease.

Patients and methods

The study included 28 untreated patients with pMAC disease. The level of serum oxidative stress was quantitatively evaluated through the diacron reactive oxygen metabolites (d-ROMs) test, which indirectly measures the level of hydroperoxide in the serum. In addition, patients were divided into three groups based on the severity shown in the computed tomographic image.

Results

The level of serum oxidative stress exceeded the normal range (250–300 U.Carr [Carratelli Units]) in all patients with pMAC disease (mean: 495.5 ± 102.6 U.Carr; minimum–maximum: 340–734 U.Carr). The level of serum oxidative stress in patients with severe disease was significantly higher compared with that observed in patients with mild disease (434.6 ± 30.2 vs. 583.4 ± 95.1, respectively, p = 0.009).

Conclusions

In patients with pMAC disease, an elevation was observed in the level of serum oxidative stress. This increase in oxidative stress was more pronounced in patients with severe disease.

Investigating Fractional Exhaled Nitric Oxide in Chronic Obstructive Pulmonary Disease (COPD) and Asthma-COPD Overlap (ACO): A Scoping Review

Chronic obstructive pulmonary disease (COPD) is the most common fixed airflow limitation. Individuals may present with the features of both asthma and COPD called asthma-COPD overlap (ACO) with more severity and worse health-related quality of life than COPD or asthma. One of the promising biomarkers that could be used in clinical practice to differentiate ACO from COPD is fractional exhaled nitric oxide (F_ENO). The role of Fractional exhaled nitric oxide (F_ENO) in COPD/ACO remains unknown. This scoping review aims to investigate the role of F_ENO measurement to differentiate COPD from ACO, to anticipate disease severity/progression and treatment response. A structured comprehensive literature search was performed in major databases including Medline, EMBASE, CINAHL, Cochrane Library, Web of Science, and BIOSIS from 2005 onwards. Thirty-eight studies were retrieved. Based on the synthesis of the reviewed literature, six themes emerged. Thirty-four articles covered more than one theme. From which, 24 articles were on modifying factors in F_ENO measurement, 18 on F_ENO in COPD compared with healthy subjects, and seven on F_ENO in ACO compared with COPD, 22 on F_ENO and disease severity/progression,12 on F_ENO and biomarkers, and eight on F_ENO and treatment response. F_ENO measurement cannot be used alone in the clinical settings of COPD patients. Although F_ENO level is higher in ACO patients than COPD-only, it is still unclear if there is a F_ENO cut-off that can be used to make the diagnosis of ACO and/or to guide therapy with inhaled corticosteroids/glucocorticoids in COPD patients.

Clinical significance of nuclear factor erythroid 2-related factor 2 in patients with chronic obstructive pulmonary disease

BACKGROUND/AIMS

Several studies have identified a role for nuclear factor erythroid 2-related factor 2 (Nrf2) in the development of chronic obstructive pulmonary disease (COPD). However, the relationship between the plasma Nrf2 level and the extent of systemic inflammation associated with COPD status remains unclear.

METHODS

Patients diagnosed with COPD were recruited from St. Paul's Hospital, The Catholic University of Korea, between July 2009 and May 2012. Patients were classified into two groups according to the severity of their symptoms on initial presentation, a COPD-stable group (n = 25) and a COPD-exacerbation group (n = 30). Seventeen patients were enrolled as a control group (n = 17). The plasma levels of Nrf2 and other systemic inf lammatory biomarkers, including interleukin 6 (IL-6), surfactant protein D (SP-D), and C-reactive protein (CRP), were measured. We collected clinical data including pulmonary function test results, and analyzed the relationships between the biomarker levels and the clinical parameters.

RESULTS

Plasma Nrf2 and CRP levels significantly increased in a stepwise manner with an increase in inflammatory status (control vs. COPD-stable vs. COPD-exacerbation) (p = 0.002, p &lt; 0.001). Other biomarkers of systemic inflammation (IL-6, SP-D) exhibited similar tendencies, but significant differences were not apparent. Furthermore, we observed negative correlations between the plasma level of Nrf2 and both the forced expiratory volume in 1 second (FEV1) (r = -0.339, p = 0.015) and the forced expiratory ratio (FEV1/forced vital capacity [FVC]) (r = -0.342, p = 0.014). However, CRP level was not correlated with any measured parameter.

CONCLUSIONS

Plasma Nrf2 levels gradually increased in line with disease severity and the extent of systemic inflammation in patients with COPD.

Immune-regulating effects of exercise on cigarette smoke-induced inflammation

Long-term cigarette smoking (LTCS) represents an important risk factor for cardiac infarction and stroke and the central risk factor for the development of a bronchial carcinoma, smoking-associated interstitial lung fibrosis, and chronic obstructive pulmonary disease. The pathophysiologic development of these diseases is suggested to be promoted by chronic and progressive inflammation. Cigarette smoking induces repetitive inflammatory insults followed by a chronic and progressive activation of the immune system. In the pulmonary system of cigarette smokers, oxidative stress, cellular damage, and a chronic activation of pattern recognition receptors are described which are followed by the translocation of the NF-kB, the release of pro-inflammatory cytokines, chemokines, matrix metalloproteases, and damage-associated molecular patterns. In parallel, smoke pollutants cross directly through the alveolus-capillary interface and spread through the systemic bloodstream targeting different organs. Consequently, LTCS induces a systemic low-grade inflammation and increased oxidative stress in the vascular system. In blood, these processes promote an increased coagulation and endothelial dysfunction. In muscle tissue, inflammatory processes activate catabolic signaling pathways followed by muscle wasting and sarcopenia. In brain, several characteristics of neuroinflammation were described. Regular exercise training has been shown to be an effective nonpharmacological treatment strategy in smoke-induced pulmonary diseases. It is well established that exercise training exerts immune-regulating effects by activating anti-inflammatory signaling pathways. In this regard, the release of myokines from contracting skeletal muscle, the elevations of cortisol and adrenalin, the reduced expression of Toll-like receptors, and the increased mobilization of immune-regulating leukocyte subtypes might be of vital importance. Exercise training also increases the local and systemic antioxidative capacity and several compensatory mechanisms in tissues such as an increased anabolic signaling in muscle or an increased compliance of the vascular system. Accordingly, regular exercise training seems to protect long-term smokers against some important negative local and systemic consequences of smoking. Data suggest that it seems to be important to start exercise training as early as possible.

Exercise training reverses inflammation and muscle wasting after tobacco smoke exposure

Long-term cigarette smoking induces inflammatory processes in the pulmonary system that are suggested to "spill over" into systemic inflammation. Regular exercise has been shown to have anti-inflammatory properties. The aim of the study was to investigate the effects of therapeutic exercise on inflammation and muscle wasting in smoke-exposed mice. C57BL/6J mice ( n = 30) were separated into three groups to receive either 1) no specific treatment (control group), 2) 8-mo exposure to cigarette smoke [smoke-exposed (SE) group], or 3) 8 mo of cigarette smoke combined with exercise training during the last 2 mo (SEex group). The inflammatory status was analyzed by quantifying levels of various plasma proteins using multiplex ELISA and detection of lymphocyte surface markers by flow cytometry. Muscle tissue was analyzed by histological techniques and measurements of RNA/protein expression. SE led to decreased maximal O₂ uptake (V̇o_2max) and maximal running speed ( V_max), which was reversed by exercise ( P < 0.05). Expression of ICAM-1, VCAM-1, and CD62L on T cells increased and was reversed by exercise ( P < 0.05). Similarly, SE induced an increase of various inflammatory cytokines, which were downregulated by exercise. In muscle, exercise improved the structure, oxidative capacity, and metabolism by reducing ubiquitin proteasome system activation, stimulating insulin-like growth factor 1 expression, and the SE-induced inhibition of mammalian target of rapamycin signaling pathway ( P < 0.05). Exercise training reverses smoke-induced decline in exercise capacity, systemic inflammation, and muscle wasting by addressing immune-regulating, anabolic, and metabolic pathways.

Circulating biomarkers of oxidative stress in chronic obstructive pulmonary disease: a systematic review

Chronic obstructive pulmonary disease (COPD) is a progressive condition characterized by airflow limitation associated with an abnormal inflammatory response of the lungs to noxious particles and gases, caused primarily by cigarette smoking. Increased oxidative burden plays an important role in the pathogenesis of COPD. There is a delicate balance between the toxicity of oxidants and the protective function of the intracellular and extracellular antioxidant defense systems, which is critically important for the maintenance of normal pulmonary functions. Several biomarkers of oxidative stress are available and have been evaluated in COPD. In this review, we summarize the main literature findings about circulating oxidative stress biomarkers, grouped according to their method of detection, measured in COPD subjects.

Serum Reactive Oxygen Metabolite Levels Predict Severe Exacerbations of Asthma

Background and Purpose

Bronchial asthma (BA) is a chronic airway disease characterized by airway hyperresponsiveness and remodeling, which are intimately linked to chronic airway inflammation. Reactive oxygen species (ROS) such as hydrogen peroxide are generated by inflammatory cells that are involved in the pathogenesis of BA. However, the role of ROS in the management of BA patients is not yet clear. We attempted to determine the role of ROS as a biomarker in the clinical setting of BA.

Subjects and Methods

We enrolled patients with BA from 2013 through 2015 and studied the degrees of asthma control, anti-asthma treatment, pulmonary function test results, fractional exhaled nitric oxide (FeNO), serum reactive oxygen metabolite (ROM) levels, and serum levels of interleukin (IL)-6 and IL-8.

Results

We recruited 110 patients with BA. Serum ROM levels correlated with white blood cell (WBC) count (rs = 0.273, p = 0.004), neutrophil count (rs = 0.235, p = 0.014), CRP (rs = 0.403, p < 0.001), and IL-6 (rs = 0.339, p < 0.001). Serum ROM levels and IL-8 and CRP levels negatively correlated with %FEV₁ (rs = -0.240, p = 0.012, rs = -0.362, p < 0.001, rs = -0.197, p = 0.039, respectively). Serum ROM levels were significantly higher in patients who experienced severe exacerbation within 3 months than in patients who did not (339 [302–381] vs. 376 [352–414] CARR U, p < 0.025). Receiver-operating characteristics analysis showed that ROM levels correlated significantly with the occurrence of severe exacerbation (area under the curve: 0.699, 95% CI: 0.597–0.801, p = 0.025).

Conclusions

Serum levels of ROM were significantly associated with the degrees of airway obstruction, WBC counts, neutrophil counts, IL-6, and severe exacerbations. This biomarker may be useful in predicting severe exacerbations of BA.

Smoking and Early COPD as Independent Predictors of Body Composition, Exercise Capacity, and Health Status

The effects of tobacco smoke, mild/moderate COPD disease and their combined effect on health status (HS), body composition (BC), and exercise capacity (EC) impairment are still unclear. We hypothesized that smoking and early COPD have a joint negative influence on these outcomes. We evaluated 32 smokers (smoking history >10 pack/years), 32 mild/moderate COPD (current smokers or former smokers), and 32 never smokers. All individuals underwent medical and smoking status evaluations, pre and post-bronchodilator spirometry, BC [fat-free mass (FFM) and FFM index (FFMI)], EC [six-minute walk distance (6MWD)] and HS [Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36)]. FFM (p = 0.02) and FFMI (p = 0.008) were lower in COPD than never smokers. 6MWT, as a percentage of reference values for the Brazilian population, was lower in COPD and smokers than never smokers (p = 0.01). Smokers showed worse SF-36 score for functional capacity than never smokers (p<0.001). SF-36 score for physical functioning (p<0.001) and role-emotional (p<0.001) were impaired in COPD patients than smokers. SF-36 scores for physical functioning (p<0.001), role-physical (p = 0.01), bodily pain (p = 0.01), vitality (p = 0.04) and role-emotional (p<0.001) were lower in COPD than never smokers. Multiple linear regression analysis showed that both COPD diagnosis and smoking were inversely associated with FFMI, 6MWD and HS. Smoking and early COPD have a joint negative influence on body composition, exercise capacity and health status.

Inflammatory Markers and the Risk of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Systemic inflammatory factors are inconsistently associated with the pathogenesis of chronic obstructive pulmonary disease (COPD). We conducted a systematic review and meta-analysis to summarize the evidence supporting the association between systemic inflammation and the risk of COPD. Pertinent studies were retrieved from PubMed, EmBase, and the Cochrane Library until April 2015. A random-effects model was used to process the data, and the analysis was further stratified by factors affecting these associations. Sensitivity analyses for publication bias were performed. We included 24 observational studies reporting data on 10,677 COPD patients and 28,660 controls. Overall, we noted that COPD was associated with elevated serum CRP (SMD: 1.21; 95%CI: 0.92–1.50; P < 0.001), leukocytes (SMD: 1.07; 95%: 0.25–1.88; P = 0.010), IL-6 (SMD: 0.90; 95%CI: 0.48–1.31; P < 0.001), IL-8 (SMD: 2.34; 95%CI: 0.69–4.00; P = 0.006), and fibrinogen levels (SMD: 0.87; 95%CI: 0.44–1.31; P < 0.001) when compared with control. However, COPD was not significantly associated with TNF-α levels when compared with control (SMD: 0.60; 95%CI: -0.46 to 1.67; P = 0.266). Our findings suggested that COPD was associated with elevated serum CRP, leukocytes, IL-6, IL-8, and fibrinogen, without any significant relationship with TNF-α.

Antioxidant activity of pomegranate juice reduces emphysematous changes and injury secondary to cigarette smoke in an animal model and human alveolar cells

BACKGROUND

Cigarette smoke (CS) increases oxidative stress (OS) in the lungs. Pomegranate juice (PJ) possesses potent antioxidant activities, attributed to its polyphenols. This study investigates the effects of PJ on the damaging effects of CS in an animal model and on cultured human alveolar cells (A549).

METHODS

Male C57BL/6J mice were divided into the following groups: Control, CS, CS + PJ, and PJ. Acute CS exposure was for 3 days, while chronic exposure was for 1 and 3 months (5 days of exposure/week). PJ groups received daily 80 μmol/kg via bottle, while other groups received distilled water. At the end of the experiments, different parameters were studied: 1) expression levels of inflammatory markers, 2) apoptosis, 3) OS, and 4) histopathological changes. In vitro, A549 cells were pretreated for 48 hours with either PJ (0.5 μM) or vehicle. Cells were then exposed to increasing concentrations of CS extracted from collected filters. Cell viability was assessed by counting of live and dead cells with trypan blue staining.

RESULTS

Acutely, a significant increase in interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α expression, apoptosis, and OS was noted in CS when compared to Control. PJ significantly attenuated the expression of inflammatory mediators, apoptosis, and OS. Chronically (at 1 and 3 months), increased expression of TNF-α was observed, and lung sections demonstrated emphysematous changes when compared to Control. PJ supplementation to CS animals attenuated the increased expression of TNF-α and normalized lung cytoarchitecture. At the cellular level, CS extract reduced cellular proliferation and triggered cellular death. Pretreatment with PJ attenuated the damaging effects of CS extract on cultured human alveolar cells.

CONCLUSION

The expression of inflammatory mediators associated with CS exposure and the emphysematous changes noted with chronic CS exposure were reduced with PJ supplementation. In vitro, PJ attenuated the damaging effects of CS extract on cultured human alveolar cells.

Association between serum interleukin-6 concentrations and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background. Interleukin-6 (IL-6) is an important pro-inflammatory cytokine and has been implicated to play a role in the systemic inflammation of patients with chronic obstructive pulmonary disease (COPD). We conducted this meta-analysis to assess the association between serum IL-6 concentrations and COPD.

Methods. PubMed and Embase were searched for eligible studies. Data were extracted by two investigators (Wei J, Xiong XF) independently and analyzed using Review Manager 5.3 and STATA 12.0 software. Standard mean differences (SMDs) and 95% confidence intervals (CI) were calculated.

Results. Thirty-three studies were included in this meta-analysis. The serum IL-6 concentrations were higher in patients with stable COPD than healthy controls (SMD = 0.65, 95% CI [0.51–0.79]). COPD patients without major comorbidities also showed higher IL-6 levels than healthy controls (SMD = 0.74, 95% CI [0.56–0.91]). COPD patients with an forced expiratory volume in one second (FEV₁) of either <50% predicted or >50% predicted had increased IL-6 concentrations compared to healthy controls (SMD = 0.77, 95% CI [0.48–1.05], SMD = 1.01, 95% CI [0.43–1.59], respectively). The serum IL-6 concentrations between mild-moderate and severe-very severe COPD patient groups were not found to be significant (SMD = −0.1, 95% CI [−0.65–0.44]).

Conclusions. This meta-analysis indicated that patients with stable COPD had higher serum IL-6 concentrations than healthy controls. No evidence showing positive or negative association between IL-6 concentrations and the severity of pulmonary function impairment was found. The correlation between IL-6 levels and pulmonary function was weak in different severities of stable COPD patients.

Targeting oxidant-dependent mechanisms for the treatment of COPD and its comorbidities

Chronic obstructive pulmonary disease (COPD) is an incurable global health burden and is characterised by progressive airflow limitation and loss of lung function. In addition to the pulmonary impact of the disease, COPD patients often develop comorbid diseases such as cardiovascular disease, skeletal muscle wasting, lung cancer and osteoporosis. One key feature of COPD, yet often underappreciated, is the contribution of oxidative stress in the onset and development of the disease. Patients experience an increased burden of oxidative stress due to the combined effects of excess reactive oxygen species (ROS) and nitrogen species (RNS) generation, antioxidant depletion and reduced antioxidant enzyme activity. Currently, there is a lack of effective treatments for COPD, and an even greater lack of research regarding interventions that treat both COPD and its comorbidities. Due to the involvement of oxidative stress in the pathogenesis of COPD and many of its comorbidities, a unique therapeutic opportunity arises where the treatment of a multitude of diseases may be possible with only one therapeutic target. In this review, oxidative stress and the roles of ROS/RNS in the context of COPD and comorbid cardiovascular disease, skeletal muscle wasting, lung cancer, and osteoporosis are discussed and the potential for therapeutic benefit of anti-oxidative treatment in these conditions is outlined. Because of the unique interplay between oxidative stress and these diseases, oxidative stress represents a novel target for the treatment of COPD and its comorbidities.

Time course of cigarette smoke-induced changes of systemic inflammation and muscle structure

It has become more evident that long-term cigarette smoking (LTCS) has an important extrapulmonary toxicity. The aim of the study was to investigate the time-dependent effects of cigarette smoke exposure on exercise capacity, markers of systemic inflammation, and skeletal muscle structure. c57bl/6j-mice were either exposed to mainstream cigarette smoke for 6 h/day, 5 days/wk [smoke-exposed (SE) group] or assigned to the control, unexposed group (Con group). SE group mice were exposed for 8, 16, 24, and 32 wk to smoke and unexposed Con mice were used as age-matched controls. Exercise capacity was investigated by spiroergometry. Systemic inflammatory status was analyzed by flow cytometry and multiplexed fluorescent immunoassay. For analysis of muscle tissue, histological techniques and microarray analysis were used. Mice of the SE group exhibited a lower increase of body mass and a decrease of V̇o2 max (P < 0.05). An increase of lymphocyte CD62, ICAM, and VCAM expression was found in SE mice (P < 0.05). A biphasic trend of protein up- and downregulation was observed in markers of systemic inflammation, tissue deterioration, and allergic reactions such as C-reactive protein (CRP), eotaxin, haptoglobin, macrophage colony-stimulating factor-1 (M-CSF-1), and macrophage inflammatory protein-1γ (MIP-1γ). Thereby, the expression of several chemotactic proteins in plasma correlated with their expression in muscle. A time-dependent decrease of muscle mass, oxidative type-I fibers, and muscle cross-sectional area was found (P < 0.05). Microarray analysis revealed a SE-induced upregulation of several pathways of metabolic processes and tissue degradation. Taken together it was found that the loss of exercise capacity and systemic inflammation are early events of SE, which might induce muscular atrophy and loss of oxidative muscle capacity.

Sarcopenia and critical illness: a deadly combination in the elderly

Sarcopenia is the age-associated loss of lean skeletal muscle mass. It is the result of multiple physiologic derangements, ultimately resulting in an insidious functional decline. Frailty, the clinical manifestation of sarcopenia and physical infirmity, is associated with significant morbidity and mortality in the elderly population. The underlying pathology results in a disruption of the individual's ability to tolerate internal and external stressors such as injury or illness. This infirmity results in a markedly increased risk of falls and subsequent morbidity and mortality from the resulting traumatic injury, as well as an inability to recover from medical insults, resulting in critical illness. The increasing prevalence of sarcopenia and critical illness in the elderly has resulted in a deadly intersection of disease processes. The lethality of this combination appears to be the result of altered muscle metabolism, decreased mitochondrial energetics needed to survive critical illness, and a chronically activated catabolic state likely mediated by tumor necrosis factor-α. Furthermore, these underlying derangements are independently associated with an increased incidence of critical illness, resulting in a progressive downward spiral. Considerable evidence has been gathered supporting the role of aggressive nutrition support and physical therapy in improving outcomes. Critical care practitioners must consider sarcopenia and the resulting frailty phenotype a comorbid condition so that the targeted interventions can be instituted and research efforts focused.

Lung injury and lung cancer caused by cigarette smoke-induced oxidative stress: Molecular mechanisms and therapeutic opportunities involving the ceramide-generating machinery and epidermal growth factor receptor

Chronic obstructive pulmonary disease (COPD) and lung cancer are frequently caused by tobacco smoking. However, these diseases present opposite phenotypes involving redox signaling at the cellular level. While COPD is characterized by excessive airway epithelial cell death and lung injury, lung cancer is caused by uncontrolled epithelial cell proliferation. Notably, epidemiological studies have demonstrated that lung cancer incidence is significantly higher in patients who have preexisting emphysema/lung injury. However, the molecular link and common cell signaling events underlying lung injury diseases and lung cancer are poorly understood. This review focuses on studies of molecular mechanism(s) underlying smoking-related lung injury (COPD) and lung cancer. Specifically, the role of the ceramide-generating machinery during cigarette smoke-induced oxidative stress leading to both apoptosis and proliferation of lung epithelial cells is emphasized. Over recent years, it has been established that ceramide is a sphingolipid playing a major role in lung epithelia structure/function leading to lung injury in chronic pulmonary diseases. However, new and unexpected findings draw attention to its potential role in lung development, cell proliferation, and tumorigenesis. To address this dichotomy in detail, evidence is presented regarding several protein targets, including Src, p38 mitogen-activated protein kinase, and neutral sphingomyelinase 2, the major sphingomyelinase that controls ceramide generation during oxidative stress. Furthermore, their roles are presented not only in apoptosis and lung injury but also in enhancing cell proliferation, lung cancer development, and resistance to epidermal growth factor receptor-targeted therapy for treating lung cancer.

Inflammatory cytokines and VEGF measured in exhaled breath condensate are correlated with tumor mass in non-small cell lung cancer

Inflammation mediated by the immune system is known to be important in carcinogenesis and, specifically, T helper 17 cells have been reported to play a role in tumor progression by promoting neo-angiogenesis. The aim of this study was to investigate whether inflammatory cytokines and vascular endothelial growth factor (VEGF) levels in exhaled breath condensate (EBC) and in serum were related to tumor size in patients with non-small cell lung cancer (NSCLC). Il-6, IL-17, TNF-α and VEGF levels were measured in EBC and serum of 15 patients with stage I-IIA NSCLC and in 30 healthy controls by immunoassay. The tumor size was measured by a CT scan. The concentrations of IL-6, IL-17 and VEGF were significantly higher in EBC of patients with lung cancer, compared with controls, while only serum IL-6 concentration was higher in patients compared to controls. A significant correlation (r = 0.78, p = 0.001) was observed between EBC levels of IL-6 and IL-17; IL-17 was also correlated to EBC levels of the VEGF (r = 0.83, p < 0.001) and TNF-α (r = 0.62, p = 0.014). The tumor diameter was significantly correlated with EBC concentrations of VEGF (r = 0.58, p = 0.039), IL-6 (r = 0.67, p = 0.013) and IL-17 (r = 0.66, p = 0.017). Our results show a significant relationship between inflammatory and angiogenic markers, measured in EBC by a non-invasive method, and tumor mass.

Peripheral blood mononuclear cell gene expression in chronic obstructive pulmonary disease

Although most cases of chronic obstructive pulmonary disease (COPD) occur in smokers, only a fraction of smokers develop the disease. We hypothesized distinct molecular signatures for COPD and emphysema in the peripheral blood mononuclear cells (PBMCs) of current and former smokers. To test this hypothesis, we identified and validated PBMC gene expression profiles in smokers with and without COPD. We generated expression data on 136 subjects from the COPDGene study, using Affymetrix U133 2.0 microarrays (Affymetrix, Santa Clara, CA). Multiple linear regression with adjustment for covariates (gender, age, body mass index, family history, smoking status, and pack-years) was used to identify candidate genes, and ingenuity pathway analysis was used to identify candidate pathways. Candidate genes were validated in 149 subjects according to multiplex quantitative real-time polymerase chain reaction, which included 75 subjects not previously profiled. Pathways that were differentially expressed in subjects with COPD and emphysema included those that play a role in the immune system, inflammatory responses, and sphingolipid (ceramide) metabolism. Twenty-six of the 46 candidate genes (e.g., FOXP1, TCF7, and ASAH1) were validated in the independent cohort. Plasma metabolomics was used to identify a novel glycoceramide (galabiosylceramide) as a biomarker of emphysema, supporting the genomic association between acid ceramidase (ASAH1) and emphysema. COPD is a systemic disease whose gene expression signatures in PBMCs could serve as novel diagnostic or therapeutic targets.

Basis for sensitive and selective time-delayed luminescence detection of hydroxyl radical by lanthanide complexes

Molecular probes for the detection of hydroxyl radical (HO•) by time-delayed luminescence spectroscopy directly in water at neutral pH with high sensitivity and selectivity are presented. The bimolecular probes consist of a lanthanide complex with open coordination sites and a reactive pre-antenna composed of an aromatic acid or amide; the latter binds to and sensitizes terbium emission upon hydroxylation by HO•. These probes exhibit long luminescence lifetimes compatible with time-delayed measurements that remove interfering background fluorescence from the sample. Six different reactive pre-antenna (benzoate, benzamide, isophthalate, isophthalamide, trimesate, and trimesamide) and two different terbium complexes [Tb-(1,4,7,10-tetraazacyclododecane-1,4,7-tris(acetic acid)) (Tb-DO3A) and Tb-(1,4,7,10-tetraazacyclododecane-1,7-bis(acetic acid)) (Tb-DO2A)] were evaluated. Of these the trimesamide/Tb-DO3A system enables the most sensitive detection of HO• with an about 1000-fold increase in metal-centered time-delayed emission upon hydroxylation of the pre-antenna to 2-hydroxytrimesamide. Excellent selectivity for both the trimesamide/Tb-DO3A and trimesate/Tb-DO3A systems over other reactive oxygen and nitrogen species are observed. Notably, the increase in metal-centered luminescence intensity is not associated with a decrease in the hydration number (q) of Tb-DO3A, suggesting that the antenna is interacting with the lanthanide via a second sphere coordination environment or that coordination by the antenna occurs by displacement of one or more of the carboxylate arms of DO3A. Formation of a weak ternary complex Tb-DO3A•hydroxytrimesamide was confirmed by temperature-dependent titration and a decrease in K(app) with increasing temperature.

Association between C-reactive Protein Concentration and Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-analysis

Objective:

This meta-analysis was conducted to summarize the association between the serum concentration of C-reactive protein (CRP) and chronic obstructive pulmonary disease (COPD).

Methods:

MEDLINE®, Cochrane Central Register of Controlled Trials, and EMBASE databases were searched for relevant studies. Data were extracted; pooled weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated.

Results:

Twenty studies were selected for final inclusion in this analysis. Patients with COPD had higher serum CRP concentrations than healthy controls (WMD 4.72 mg/l, 95% CI 2.98, 6.47). In addition, patients with severe COPD had higher serum CRP concentrations than those with moderate COPD (WMD 1.26 mg/l, 95% CI 0.78, 1.73). There was no significant difference in serum CRP concentration between patients with mild and moderate COPD (WMD 0.67 mg/l, 95% CI -0.08, 1.42).

Conclusions:

This meta-analysis suggested that patients with stable COPD had higher serum CRP concentrations than healthy controls. CRP might be an indicator of disease severity in patients with COPD, thus highlighting the importance of measuring serum CRP concentrations in patients with stable COPD.

TNF-α is associated with loss of lean body mass only in already cachectic COPD patients

Background

Systemic inflammation may contribute to cachexia in patients with chronic obstructive pulmonary disease (COPD). In this longitudinal study we assessed the association between circulating C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 levels and subsequent loss of fat free mass and fat mass in more than 400 COPD patients over three years.

Methods

The patients, aged 40–76, GOLD stage II-IV, were enrolled in 2006/07, and followed annually. Fat free mass and fat mass indexes (FFMI & FMI) were calculated using bioelectrical impedance, and CRP, TNF-α, IL-1ß, and IL-6 were measured using enzyme immunoassays. Associations with mean change in FFMI and FMI of the four inflammatory plasma markers, sex, age, smoking, FEV₁, inhaled steroids, arterial hypoxemia, and Charlson comorbidity score were analyzed with linear mixed models.

Results

At baseline, only CRP was significantly (but weakly) associated with FFMI (r = 0.18, p < 0.01) and FMI (r = 0.27, p < 0.01). Univariately, higher age, lower FEV₁, and use of beta2-agonists were the only significant predictors of decline in FFMI, whereas smoking, hypoxemia, Charlson score, and use of inhaled steroids predicted increased loss in FMI. Multivariately, high levels of TNF-α (but not CRP, IL-1ß or IL-6) significantly predicted loss of FFMI, however only in patients with established cachexia at entry.

Conclusion

This study does not support the hypothesis that systemic inflammation is the cause of accelerated loss of fat free mass in COPD patients, but suggests a role for TNF-α in already cachectic COPD patients.

Role of vasoactive intestinal peptide in hyperoxia-induced injury of primary type II alveolar epithelial cells

OBJECTIVE

We investigated the effect of VIP on primary type II alveolar epithelial cells (AECIIs) upon the exposure of hyperoxia.

METHODS

AECIIs were isolated and purified from premature rats and exposed to air (21% oxygen), hyperoxia(95% oxygen), VIP+air and VIP+hyperoxia, respectively. The proliferation and apoptosis of AECIIs were detected by MTT cell proliferation assay, flow cytometry and western blot. The production of intracellular reactive oxygen species (ROS) was determined by 2 ', 7'-dichloro-dihydrotestosterone fluorescein diacetate (DCFH-DA) molecular probe and the total antioxidant capacity (TAOC) by ultraviolate spectro-photometer.

RESULTS

Cell proliferation significantly increased and apoptosis decreased upon the treatment with VIP. In addition, the level of ROS in the hyperoxia+VIP group was significantly lower than in the hyperoxia group, in contrast, TAOC was higher in the hyperoxia+VIP group than that in the hyperoxia group.

CONCLUSIONS

VIP exerts a protective role in the hyperoxia-induced oxidative stress damage in AECIIs, which probably attributed to its anti-oxidant and anti-apoptosis property.

Advanced glycation end products and its receptor (RAGE) are increased in patients with COPD

Advanced Glycation End products (AGEs) are the products of nonenzymatic glycation and oxidation of proteins and lipids. Formation of AGEs is increased in response to hyperglycaemia, reactive oxygen species and ageing. AGEs are proinflammatory and can modify the extracellular matrix. RAGE (Receptor for Advanced Glycation End Products) mediates some of the effects of AGEs.

METHODS

Formalin-fixed lung tissue from patients who had lobectomy for bronchial carcinoma was used to investigate the presence of AGEs and RAGE. Subjects were divided into those with COPD and controls. Immunostaining for AGEs and RAGE was performed and the intensity of staining measured.

RESULTS

Subjects with COPD and controls were similar in age and smoking history but FEV(1)% predicted was lower for COPD than controls. Intensity of staining for AGEs was greater in the airways (p = 0.025) and alveolar walls (p = 0.004) in COPD. Intensity of staining for RAGE was also significantly increased in alveolar walls (p = 0.03) but not the airways. FEV(1)% predicted was correlated with the intensity of staining for AGEs in the airways and alveoli.

CONCLUSIONS

The increased staining for both AGEs and RAGE in COPD lung raises the possibility that the RAGE-AGEs interaction may have a role in the pathogenesis of COPD.

Hypertension, systemic inflammation and body weight in relation to lung function impairment-an epidemiological study

Recent reports on the simultaneous occurrence of systemic inflammation and airflow obstruction are usually based on a highly selective patient population, but their importance warrants further evaluation in the general population. The objectives were to study the interrelationship between airflow obstruction, smoking, hypertension, obesity and CRP as a marker of systemic inflammation in a randomly selected sample of the general Icelandic population (n = 939). This study comprised 758 randomly selected men and women 40 years and older living in Reykjavik, Iceland, and who were participating in the Burden of Obstructive Lung Disease (BOLD) study (81% response rate). In addition to the BOLD protocol, which included post-bronchodilator spirometry, they answered questions about general health and medication. Serum samples were taken for measurement of C-reactive protein (CRP). In the sample-245 individuals (33%) reported having hypertension. Subjects with hypertension were older, had a higher BMI and higher CRP levels. Subjects with hypertension had lower values of FEV(1) than predicted (89.9 +/- 18.5 vs. 94.5 +/- 14.4%) (p < 0.001) and FVC (92.2 +/- 15.1 vs. 95.3 +/- 12.3%) (p = 0.002). These differences remained significant after adjusting for age, BMI, CRP and smoking. Hypertension and CRP levels above the median were both independently and additively associated with lower FEV(1) and FVC. In addition a lower FVC% was also associated with a higher BMI (> 30 mg/m2). Use of betablocking antihypertensives was not related to lung function. Hypertension, BMI and systemic inflammation affect lung function independently of each other. All three variables have a negative effect on FVC, while hypertension and high CRP were independently associated with impaired FEV(1).

Neuropeptide substance P attenuates hyperoxia-induced oxidative stress injury in type II alveolar epithelial cells via suppressing the activation of JNK pathway

Hyperoxia-induced oxidative stress plays a key role in many pulmonary diseases. In an earlier study we found the protective effect of the neuropeptide substance P (SP) on type II alveolar epithelial cells (AECIIs) after hyperoxia exposure. Then, we investigated c-Jun N-terminal kinase (C-JNK) signal transduction pathways in AECIIs before and after hyperoxia exposure. Primary AECIIs were isolated and purified from premature rats. Subsequently, the cells were treated with air (21% oxygen), hyperoxia (95% oxygen), SP+ air, and SP+ hyperoxia. SP was added in advance to reach a final concentration 1 x 10(-6) mol/l. The cells were then exposed to air and hyperoxia for 12, 24, and 48 h. XTT cell proliferation assay and fluorescence-activated cell sorting (FACS) were employed to detect cell growth and apoptosis. Phosphorylated JNK (p-JNK) levels were measured using Western blot assay. The morphological alteration of AECIIs was observed using a transmission electron microscope (TEM). Compared with the simple hyperoxia treatment, the cell growth and apoptosis percentage was significantly increased and decreased after adding additional SP. Meanwhile, the reduced levels of p-JNKs could be found after adding SP. Furthermore, the morphological damage of AECIIs was greatly improved. These data suggest that SP can promote AECII proliferation and inhibit apoptosis by suppressing JNK signal pathways after hyperoxia exposure, which attenuates hyperoxia-induced oxidative stress damage in AECIIs. It might be a potential therapy for acute pulmonary injury under hyperoxia-induced oxidative stress.

Discovery of (S)-N-[2-[1-(3-ethoxy-4-methoxyphenyl)-2-methanesulfonylethyl]-1,3-dioxo-2,3-dihydro-1H-isoindol-4-yl] acetamide (apremilast), a potent and orally active phosphodiesterase 4 and tumor necrosis factor-alpha inhibitor

In this communication, we report the discovery of 1S (apremilast), a novel potent and orally active phosphodiesterase 4 (PDE4) and tumor necrosis factor-alpha inhibitor. The optimization of previously reported 3-(1,3-dioxo-1,3-dihydroisoindol-2-yl)-3-(3,4-dimethoxyphenyl)propionic acid PDE4 inhibitors led to this series of sulfone analogues. Evaluation of the structure-activity relationship of substitutions on the phthalimide group led to the discovery of an acetylamino analogue 1S, which is currently in clinical trials.

Amelioration of pulmonary dysfunction and neutrophilic inflammation by PPAR gamma agonist in LPS-exposed guinea pigs

Airway dysfunction and pulmonary neutrophilic inflammation are the major characteristics of inflammatory conditions of lungs like chronic obstructive pulmonary disease (COPD). Lipopolysaccharide (LPS), a constituent of cigarette smoke, has been identified as the most important risk factor for COPD development. Inhalation exposure to LPS or cigarette smoke elicits an inflammatory response accompanied by airway hyperresponsiveness, elevated proinflammatory mediators and inflammatory cells similar to COPD. In the present study, we have evaluated the effects of pioglitazone, a peroxisome proliferator-activated receptor gamma (PPAR gamma) agonist, in LPS-induced pulmonary dysfunction, inflammatory changes and oxidative stress in guinea pigs. Inhalation exposure to nebulised LPS (30 microg ml(-1)) resulted in significant increase in the breathing frequency and bronchoconstriction accompanied with a significant decrease in tidal volume. Our results demonstrated that the LPS-induced pulmonary dysfunction was temporally associated with neutrophil infiltration as evident from heavy neutrophilia, increased TNFalpha in bronchoalveolar lavage fluid (BAL), elevated myeloperoxidase (MPO) level and histology of the lung tissue. Exposure to LPS also produced significant increase in tissue malondialdehyde (MDA) level indicating underlying oxidative stress. The results also reveal that pioglitazone (3, 10 and 30 mg kg(-1), p.o.) is effective in abrogating the pulmonary dysfunction by attenuating neutrophilia, TNFalpha release and oxidative stress in LPS-induced model of acute lung inflammation. Results from the present study have added to the emergent body of evidence that PPAR gamma agonists are effective in the therapy of inflammatory disease of the lungs.