Upregulation of Notch Signaling and Cell-Differentiation Inhibitory Transcription Factors in Stable Chronic Obstructive Pulmonary Disease Patients.

Notch signaling is involved in the prevention of cell differentiation and cell fate in various organs, including the lungs. We aimed to determine the transcriptomic and protein expression of Notch receptors, their ligands, and related transcription factors in stable COPD. The expression and localization of Notch receptors, their ligands, and related transcription factors were measured in bronchial biopsies of individuals with stable mild/moderate (MCOPD) (n = 18) or severe/very severe (SCOPD) (n = 16) COPD, control smokers (CSs) (n = 13), and control nonsmokers (CNSs) (n = 11), and in the lung parenchyma of those with MCOPD (n = 13), CSs (n = 10), and CNSs (n = 10) using immunohistochemistry, ELISA tests, and transcriptome analyses. In the bronchial biopsies, Notch4 and HES7 significantly increased in the lamina propria of those with SCOPD compared to those with MCOPD, CSs, and CNSs. In the peripheral lung bronchiolar epithelium, Notch1 significantly increased in those with MCOPD and CSs compared to CNSs. ELISA tests of lung parenchyma homogenates showed significantly increased Notch2 in those with MCOPD compared to CSs and CNSs. Transcriptomic data in lung parenchyma showed increased DLL4 and HES1 mRNA levels in those with MCOPD and CSs compared to CNSs. These data show the increased expression of the Notch pathway in the lungs of those with stable COPD. These alterations may play a role in impairing the regenerative-reparative responses of diseased bronchioles and lung parenchyma.

Comparison among populations with severe and intermediate alpha1-antitrypsin deficiency and chronic obstructive pulmonary disease.

BACKGROUND: Severe alpha1-antitrypsin (AAT) deficiency (AATD) is associated with a high risk of airflow obstruction and emphysema. The risk of lung disease in those with intermediate AAT deficiency is unclear. Our aims were to compare pulmonary function, time of onset of symptoms, and indicators of quality of life among patients with severe AATD (PI*ZZ), patients with intermediate AATD (PI*MZ) from the Italian Registry of AATD with a chronic obstructive pulmonary disease (COPD) cohort of patients without AATD (PI*MM). METHODS: We considered a total of 613 patients: 330 with the PI*ZZ genotype, 183 with the PI*MZ genotype and 100 with the PI*MM genotype. Radiological exams, pulmonary function test, and measurement of quality of life have been performed on all cohorts of patients. RESULTS: The three populations differ significantly in terms of age at COPD/AATD diagnosis (P=0.00001), respiratory function (FEV1, FVC, DLCO P<0.001), quality of life (P=0.0001) and smoking history (P<0.0001). PI*ZZ genotype had 24.9 times a higher likelihood of developing airflow obstruction. The MZ genotype is not associated with a significant early risk of airflow obstruction. CONCLUSIONS: The comparison of populations with PI*ZZ, MZ and MM genotypes allows to delineate the role of alpha1-antitrypsin deficiency on respiratory function and on the impact on quality of life, in relation to other risk factors. These results highlight the crucial role of primary and secondary prevention on smoking habits in PI*MZ subjects and the importance of an early diagnosis.

Impaired autophagy in the lower airways and lung parenchyma in stable COPD.

Background: There is increasing evidence of autophagy activation in COPD, but its role is complex and probably regulated through cell type-specific mechanisms. This study aims to investigate the autophagic process at multiple levels within the respiratory system, using different methods to clarify conflicting results reported so far. Methods: This cross-sectional study was performed on bronchial biopsies and peripheral lung samples obtained from COPD patients (30 and 12 per sample type, respectively) and healthy controls (25 and 22 per sample type, respectively), divided by smoking history. Subjects were matched for age and smoking history. We analysed some of the most important proteins involved in autophagosome formation, such as LC3 and p62, as well as some molecules essential for lysosome function, such as lysosome-associated membrane protein 1 (LAMP1). Immunohistochemistry was used to assess the autophagic process in both sample types. ELISA and transcriptomic analysis were performed on lung samples. Results: We found increased autophagic stimulus in smoking subjects, regardless of respiratory function. This was revealed by immunohistochemistry through a significant increase in LC3 (p<0.01) and LAMP1 (p<0.01) in small airway bronchiolar epithelium, alveolar septa and alveolar macrophages. Similar results were obtained in bronchial biopsy epithelium by evaluating LC3B (p<0.05), also increased in homogenate lung tissue using ELISA (p<0.05). Patients with COPD, unlike the others, showed an increase in p62 by ELISA (p<0.05). No differences were found in transcriptomics analysis. Conclusions: Different techniques, applied at post-transcriptional level, confirm that cigarette smoke stimulates autophagy at multiple levels inside the respiratory system, and that autophagy failure may characterise COPD.

Bacterial load and related innate immune response in the bronchi of rapid decliners with chronic obstructive pulmonary disease.

BACKGROUND: Characterization of COPD patients with rapid lung functional decline is of interest for prognostic and therapeutic reasons. We recently reported an impaired humoral immune response in rapid decliners. OBJECTIVE: To determine the microbiota associated to markers of innate immune host response in COPD patients with rapid lung functional decline. METHODS: In COPD patients monitored for at least 3 years (mean ± SD: 5.8 ± 3 years) for lung functional decline, the microbiota and related markers of immune response was measured in bronchial biopsies of patients with different lung functional decline (rate of FEV1% lung functional decline: no decline FEV1%, ≤20 ml/year n = 21, slow decline FEV1%, >20 ≤ 70 ml/year, n = 14 and rapid decline FEV1%, >70 ml/year, n = 15) using qPCR for microbiota and immunohistochemistry for cell-receptors and inflammatory markers. MAIN RESULTS: Pseudomonas aeruginosa and Streptococcus pneumoniae were increased in rapid decliners vs slow decliners, S. pneumoniae was also increased compared to non decliners. In all patients, S. pneumoniae (copies/ml) positively correlated with pack-years consumption, lung function decline, TLR4, NOD1, NOD2 scored in bronchial epithelium and NOD1/mm2 in lamina propria. CONCLUSION: These data show an imbalance of microbiota components in rapid decliners which is associated to the expression of the related cell-receptors in all COPD patients. These findings may help in the prognostic stratification and treatment of patients.

Airflow grades, outcome measures and response to pulmonary rehabilitation in individuals after an exacerbation of severe chronic obstructive pulmonary disease.

BACKGROUND: Individuals with COPD may be staged according to symptoms and exacerbation history (GOLD groups: A-D) and on airflow obstruction (GOLD grades: 1-4). Guidelines recommend pulmonary rehabilitation (PR) for these individuals, including those recovering from an exacerbation (ECOPD) OBJECTIVE: To evaluate whether in individuals with clinically severe COPD, recovering from an ECOPD, the effect size of an in-hospital PR program would be affected by airflow severity grades and assessed outcome measures. METHODS: Retrospective, multicentre study. Participants were compared according to different GOLD airflow grades. In addition to the MRC dyspnoea scale, six-minute walking distance test and COPD assessment test (CAT), Barthel dyspnoea index (Bid), and Short Physical Performance Battery (SPPB) were assessed, evaluating the proportion of individuals reaching the minimum clinically important difference (MCID) (responders). RESULTS: Data of 479 individuals, completing the program were evaluated. Most of the participants were allocated in GOLD grades 4, (57.6%) and 3 (22.1%). All outcome measures significantly improved after PR (p < 0.05), without any significant difference in the proportion of responders in any measure. CONCLUSIONS: in individuals with severe COPD, recovering from ECOPD the success rate of PR does not depend on airflow severity, or outcome measure assessed. In addition to the most used outcome measures, also Bid and SPPB are sensitive to PR.

Effectiveness of pulmonary rehabilitation in individuals with Chronic Obstructive Pulmonary Disease according to inhaled therapy: The Maugeri study.

BACKGROUND AND AIM: Real-life studies report discordant prescribing of inhaled triple therapy (TT) among individuals with COPD. Guidelines recommend pulmonary rehabilitation (PR) for persistent breathlessness and/or exercise limitation. This real-life study aimed to assess the effects of in-patient PR in individuals under TT as compared to other inhaled therapies (no TT). METHODS: Multicentric, retrospective analysis of data from individuals admitted to in-hospital PR. Baseline characteristics were recorded and lung function was assessed. Outcome measures were: 6-min walking test (6MWT: primary outcome), Medical Research Council (MRC) scale for dyspnoea, and COPD assessment test (CAT). RESULTS: Data of pre and post program 6MWT of 1139 individuals were available. Pulmonary rehabilitation resulted in significant improvement in 6MWT in both groups, however, the effect size (by 54.3 ± 69.7 vs 42.5 ± 64.2 m, p = 0.004) and proportion of individuals reaching the minimal clinically important difference (MCID) of 6MWT (64.2%, vs 54.3%, p = 0.001) were higher in TT group. Both groups significantly improved also the other outcome measures. The significant independent predictors of reaching the MCID of 6MWT were hospital provenience, TT use, and high eosinophils count. CONCLUSION: Pulmonary rehabilitation results in significant benefits in individuals with COPD irrespective of the use of TT. However, individuals under TT report larger benefits in exercise tolerance than those under no TT.

Decreased humoral immune response in the bronchi of rapid decliners with chronic obstructive pulmonary disease.

BACKGROUND: Identification of COPD patients with a rapid decline in FEV1 is of particular interest for prognostic and therapeutic reasons. OBJECTIVE: To determine the expression of markers of inflammation in COPD patients with rapid functional decline in comparison to slow or no decliners. METHODS: In COPD patients monitored for at least 3 years (mean ± SD: 5.8 ± 3 years) for lung functional decline, the expression and localization of inflammatory markers was measured in bronchial biopsies of patients with no lung functional decline (FEV1% + 30 ± 43 ml/year, n = 21), slow (FEV1% ml/year, - 40 ± 19, n = 14) and rapid decline (FEV1% ml/year, - 112 ± 53, n = 15) using immunohistochemistry. ELISA test was used for polymeric immunoglobulin receptor (pIgR) quantitation "in vitro". RESULTS: The expression of secretory IgA was significantly reduced in bronchial epithelium (p = 0.011) and plasma cell numbers was significantly reduced in the bronchial lamina propria (p = 0.017) of rapid decliners compared to no decliners. Bronchial inflammatory cell infiltration, CD4, CD8, CD68, CD20, NK, neutrophils, eosinophils, mast cells, pIgR, was not changed in epithelium and lamina propria of rapid decliners compared to other groups. Plasma cells/mm2 correlated positively with scored total IgA in lamina propria of all patients. "In vitro" stimulation of 16HBE cells with LPS (10 µg/ml) and IL-8 (10 ng/ml) induced a significant increase while H2O2 (100 µM) significantly decreased pIgR epithelial expression. CONCLUSION: These data show an impaired humoral immune response in rapid decliners with COPD, marked by reduced epithelial secretory IgA and plasma cell numbers in the bronchial lamina propria. These findings may help in the prognostic stratification and treatment of COPD.

An Italian expert consensus on the management of alpha1-antitrypsin deficiency: a comprehensive set of algorithms.

BACKGROUND: Alpha1-antitrypsin deficiency (AATD) is a genetic-based risk condition, mainly affecting the lungs and liver. Despite its wide distribution, it is largely underdiagnosed, thus being considered a rare disease, and is consequently managed in ad-hoc reference centers. Unfortunately, an easy-to-use algorithm for managing such a complex disease is still lacking. METHODS: An expert consensus meeting was conducted among experts in the management of AATD to build a comprehensive algorithm, including diagnosis, monitoring, AAT therapy, rehabilitation and lung transplantation, and liver disease, that could serve as a guide for physicians and treating centers. A panel of AATD specialists evaluated the results of their work. RESULTS: Diagnosis is the most delicate phase, and awareness about this condition should be raised among GPs. A set of recommendations has been written about the most suitable follow-up visits. Augmentation therapy with AAT may be useful to reduce the progression of emphysema and lung function decline in selected patients. Exercise capacity may be improved by pulmonary rehabilitation and, in selected cases, by lung volume reduction or lung transplantation. Support therapies are needed for those who develop liver disease, and, in selected cases, liver transplantation may be considered. Patients should be carefully educated about their lifestyle, including smoking cessation, body weight control, and reduced alcohol intake. CONCLUSIONS: The proposed algorithm obtained the endorsement of the Italian Society of Pneumology (SIP). However, further studies and additional clinical data are required to confirm the validity of these recommendations.

Pathogenesis of COPD at the cellular and molecular level.

Chronic inflammatory responses in the lung of patients with stable mild-to-severe forms of chronic obstructive pulmonary disease (COPD) play a central role in the definition, comprehension and monitoring of the disease state. A better understanding of the COPD pathogenesis cannot avoid a detailed knowledge of these inflammatory changes, altering the functional health of the lung during the disease progression. We summarize and discuss the role and principal functions of the inflammatory cells populating the large, small airways and lung parenchyma of patients with COPD of increasing severity in comparison with healthy control subjects: T and B lymphocytes, NK and innate lymphoid cells, macrophages, and neutrophils. The differential inflammatory distribution in large and small airways of patients is also discussed. Furthermore, relevant cellular mechanisms controlling the homeostasis and the "normal" balance of these inflammatory cells and of structural cells in the lung, such as autophagy, apoptosis, necroptosis and pyroptosis are as well presented and discussed in the context of the COPD severity.

The respiratory rehabilitation Maugeri network service reconfiguration after 1 year of COVID-19.

As part of the Italian Health Service the respiratory ICS Maugeri network were reconfigured and several in-hospital programs were suspended to be substituted by workforce and facilities reorganization for acute and post-acute COVID-19 care need. The present review shows the time course variation of respiratory ICS network in terms of admissions diagnosis and outcomes. A comparative review of the admissions and outcome measures data (anthropometric, admission diagnosis, provenience, comorbidities, disability, symptoms, effort tolerance, disease impact, length of stay and discharge destinations) over 1 year period (March 2020-March 2021) was undertaken and compared to retrospective data from a corresponding 1 year (March 2019-March 2020) period to determine the impact of the network relocation on the delivery of pulmonary specialist rehabilitation to patients with complex needs during the pandemic episode. One of the changes implemented at the respiratory Maugeri network was the relocation of the Pulmonary Rehabilitation units from its 351 beds base to a repurposed 247 beds and a reduction in total number of admitted patients (n=3912 in pre-COVID time; n=2089 in post COVID time). All respiratory diagnosis, except COVID sequelae, decreased (chronic respiratory failure-CRF, COPD, obstructive sleep apnoea syndrome-OSAS, interstitial lung disease-ILD, tracheostomized patients and other mixed diseases decreased of 734, 705, 157, 87, 79 and 326 units respectively). During the pandemic time, 265 post COVID sequelae with CRF were admitted for rehabilitation (12.62%), % of patients coming from acute hospital increased, LOS and NIV use remained stable while CPAP indication decreased. Disease impact, dyspnea and effort tolerance as their improvements after rehabilitation, were similar in the two periods.  Only baseline disability, expressed by Barthel index, seems higher in the 2° observation time as its improvement. Hospital deaths and transfers to acute hospitals were higher during pandemic crisis while home destination decreased. This review demonstrated impact of coronavirus pandemic situation, specifically the relocation of the respiratory inpatient rehabilitation wards in a huge Italian network.

Prevalence and clinical features of most frequent phenotypes in the Italian COPD population: the CLIMA Study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a complex, progressive respiratory condition characterized by heterogeneous clinical presentations (phenotypes). The aim of this study was to assess the prevalence of the main COPD phenotypes and match of each phenotype to the most fitting clinical and lung function profile. METHODS: the CLIMA (Clinical Phenotypes in Actual Clinical Practice) study was an observational, cross-sectional investigation involving twenty-four sites evenly distributed throughout Italy. Patients were tentatively grouped based on their history and claimed prevailing symptoms at recruitment: chronic cough (CB, suggesting chronic bronchitis); dyspnoea (possible emphysema components, E); recurrent wheezing (presuming asthma components, A). Variables collected were: anagraphics; smoking habit; history of asthma; claim of >1 exacerbations in the previous year; blood eosinophil count; total blood IgE and alpha1 anti-trypsin (α1-AT) levels; complete lung function, and the chest X-ray report. mMRC, CAT, BCS, EQ5d-5L were also used. The association between variables and phenotypes were checked by Chi-square test and multinomial logistic regression. RESULTS: The CB phenotype was prevalent (48.3%), followed by the E and the A phenotypes (38.8% and 12.8%, respectively). When dyspnoea was the prevailing symptom, the probability of belonging to the COPD-E phenotype was 3.40 times higher. Recurrent wheezing was mostly related to the COPD-A phenotype. Lung function proved more preserved in the COPD-CB phenotype. Smoke; n. exacerbations/year; VR, and BODE index were positively correlated with the COPD-E phenotype, while SpO2, FEV1/FVC, FEV1/VC, and FEV1 reversibility were negatively correlated. Lower DLco values were highly probative for the COPD-E phenotype (p<0.001). Conversely, smoke, wheezing, plasma eosinophils, FEV1 reversibility, and DLco were positively correlated with the COPD-A phenotype. The probability of belonging to the COPD-A phenotype raised by 2.71 times for any increase of one unit in % plasma eosinophils (p<0.001). Also multiparametrical scores contributed to discriminate the three phenotypes. CONCLUSION: The recognition of the main phenotypes of COPD can be effectively pursued by means of a few clinical and instrumental parameters, easy to obtain also in current daily practice. The phenotypical approach is crucial in the management of COPD as it allows to individualize the therapeutic strategy and to obtain more effective clinical outcomes.

Characteristics of COVID-19 Pneumonia Survivors With Resting Normoxemia and Exercise-Induced Desaturation.

BACKGROUND: Survivors of coronavirus disease 2019 (COVID-19) associated pneumonia may show exercise-induced desaturation. We wondered whether these individuals show physiologic and symptom characteristics similar to individuals with chronic respiratory diseases with exercise-induced desaturation, namely COPD or interstitial lung diseases (ILD). We evaluated lung function, exercise capacity, and symptoms in these individuals compared with individuals with COPD or ILD and exercise-induced desaturation. METHODS: Survivors of COVID-19 associated pneumonia (study individuals), normoxemic at rest with exercise-induced desaturation, underwent assessment of dyspnea, dynamic lung volumes, carbon monoxide diffusion capacity, and the 6-min walk test. Data of individuals with COPD or with ILD and exercise-induced desaturation were also retrospectively analyzed. RESULTS: FVC was lower in individuals with COVID-19 or ILD than in those with COPD. Individuals who had COVID-19 walked < 70% of predicted and, as a whole, had a 6-min walk test performance similar to individuals with ILD but walked significantly less, showed more severe leg fatigue and dyspnea during exercise, and more exercise-induced desaturation than individuals with COPD. CONCLUSIONS: Survivors of COVID-19 associated pneumonia, who were normoxemic at rest with exercise-induced desaturation, had alterations in lung function, exercise capacity, and symptoms similar to individuals with ILD but more severe than individuals with COPD and exercise-induced desaturation.

Airway Clearance Techniques: The Right Choice for the Right Patient.

The management of bronchial secretions is one of the main problems encountered in a wide spectrum of medical conditions ranging from respiratory disorders, neuromuscular disorders and patients undergoing either thoracic or abdominal surgery. The purpose of this review is illustrate to the reader the different ACTs currently available and the related evidence present in literature. Alongside methods with a strong background behind as postural drainage, manual techniques or PEP systems, the current orientation is increasingly aimed at devices that can mobilize and / or remove secretions. Cough Assist, Vacuum Techniques, systems that modulate airflow have more and more scientific evidence. Different principles combination is a new field of investigation that goes toward an increasing of clinical complexity that will facing us.

Bacterial and viral infections and related inflammatory responses in chronic obstructive pulmonary disease.

In chronic obstructive pulmonary disease (COPD) patients, bacterial and viral infections play a relevant role in worsening lung function and, therefore, favour disease progression. The inflammatory response to lung infections may become a specific indication of the bacterial and viral infections. We here review data on the bacterial-viral infections and related airways and lung parenchyma inflammation in stable and exacerbated COPD, focussing our attention on the prevalent molecular pathways in these different clinical conditions. The roles of macrophages, autophagy and NETosis are also briefly discussed in the context of lung infections in COPD. Controlling their combined response may restore a balanced lung homeostasis, reducing the risk of lung function decline. KEY MESSAGE Bacteria and viruses can influence the responses of the innate and adaptive immune system in the lung of chronic obstructive pulmonary disease (COPD) patients. The relationship between viruses and bacterial colonization, and the consequences of the imbalance of these components can modulate the inflammatory state of the COPD lung. The complex actions involving immune trigger cells, which activate innate and cell-mediated inflammatory responses, could be responsible for the clinical consequences of irreversible airflow limitation, lung remodelling and emphysema in COPD patients.

Minimal Clinically Important Difference in Barthel Index Dyspnea in Patients with COPD.

Background: The Barthel Index dyspnea (BId) is responsive to physiological changes and pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD). However, the minimum clinically important difference (MCID) has not been established yet. Aim: To identify the MCID of BId in patients with COPD stratified according to the presence of chronic respiratory failure (CRF) or not. Materials and Methods: Using the Medical Research Council (MRC) score as an anchor, receiver operating characteristic curves and quantile regression were retrospectively evaluated before and after pulmonary rehabilitation in 2327 patients with COPD (1151 of them with CRF). Results: The median post-rehabilitation changes in BId for all patients were -10 (interquartile range = -17 to -3, p<0.001), correlating significantly with changes in MRC (r = 0.57, 95% CI = 0.53 to 0.59, p<0.001). Comparing different methods of assessment, the MCID ranged from -6.5 to -9 points for patients without and -7.5 to -12 points for patients with CRF. Conclusion: The most conservative estimate of the MCID is -9 points in patients with COPD, without and -12 in those with CRF. This estimate may be useful in the clinical interpretation of data, particularly in response to intervention studies.

Extracorporeal Shock Waves Increase Markers of Cellular Proliferation in Bronchial Epithelium and in Primary Bronchial Fibroblasts of COPD Patients.

Chronic obstructive pulmonary disease (COPD) is due to structural changes and narrowing of small airways and parenchymal destruction (loss of the alveolar attachment as a result of pulmonary emphysema), which all lead to airflow limitation. Extracorporeal shock waves (ESW) increase cell proliferation and differentiation of connective tissue fibroblasts. To date no studies are available on ESW treatment of human bronchial fibroblasts and epithelial cells from COPD and control subjects. We obtained primary bronchial fibroblasts from bronchial biopsies of 3 patients with mild/moderate COPD and 3 control smokers with normal lung function. 16HBE cells were also studied. Cells were treated with a piezoelectric shock wave generator at low energy (0.3 mJ/mm2, 500 pulses). After treatment, viability was evaluated and cells were recultured and followed up for 4, 24, 48, and 72 h. Cell growth (WST-1 test) was assessed, and proliferation markers were analyzed by qRT-PCR in cell lysates and by ELISA tests in cell supernatants and cell lysates. After ESW treatment, we observed a significant increase of cell proliferation in all cell types. C-Kit (CD117) mRNA was significantly increased in 16HBE cells at 4 h. Protein levels were significantly increased for c-Kit (CD117) at 4 h in 16HBE (p < 0.0001) and at 24 h in COPD-fibroblasts (p = 0.037); for PCNA at 4 h in 16HBE (p = 0.046); for Thy1 (CD90) at 24 and 72 h in CS-fibroblasts (p = 0.031 and p = 0.041); for TGFß1 at 72 h in CS-fibroblasts (p = 0.038); for procollagen-1 at 4 h in COPD-fibroblasts (p = 0.020); and for NF-κB-p65 at 4 and 24 h in 16HBE (p = 0.015 and p = 0.0002). In the peripheral lung tissue of a representative COPD patient, alveolar type II epithelial cells (TTF-1+) coexpressing c-Kit (CD117) and PCNA were occasionally observed. These data show an increase of cell proliferation induced by a low dosage of extracorporeal shock waves in 16HBE cells and primary bronchial fibroblasts of COPD and control smoking subjects.

Evaluation of Innate Immune Mediators Related to Respiratory Viruses in the Lung of Stable COPD Patients.

Background: Little is known about the innate immune response to viral infections in stable Chronic Obstructive Pulmonary Disease (COPD). Objectives: To evaluate the innate immune mediators related to respiratory viruses in the bronchial biopsies and lung parenchyma of stable COPD patients. Methods: We evaluated the immunohistochemical (IHC) expression of Toll-like receptors 3-7-8-9 (TLR-3-7-8-9), TIR domain-containing adaptor inducing IFNß (TRIF), Interferon regulatory factor 3 (IRF3), Phospho interferon regulatory factor 3  ( pIRF3), Interferon regulatory factor 7 (IRF7), Phospho interferon regulatory factor 7 (pIRF7), retinoic acid-inducible gene I (RIG1), melanoma differentiation-associated protein 5 (MDA5), Probable ATP-dependent RNA helicase DHX58 ( LGP2), Mitochondrial antiviral-signaling protein (MAVS), Stimulator of interferon genes (STING), DNA-dependent activator of IFN regulatory factors (DAI), forkhead box protein A3(FOXA3), Interferon alfa (IFNα), and Interferon beta (IFNß) in the bronchial mucosa of patients with mild/moderate (n = 16), severe/very severe (n = 18) stable COPD, control smokers (CS) (n = 12), and control non-smokers (CNS) (n = 12). We performed similar IHC analyses in peripheral lung from COPD (n = 12) and CS (n = 12). IFNα and IFNß were assessed in bronchoalveolar lavage (BAL) supernatant from CNS (n = 8), CS (n = 9) and mild/moderate COPD (n = 12). Viral load, including adenovirus-B, -C, Bocavirus, Respiratory syncytial Virus (RSV),Human Rhinovirus (HRV), Coronavirus, Influenza virus A (FLU-A), Influenza virus B (FLU-B), and Parainfluenzae-1 were measured in bronchial rings and lung parenchyma of COPD patients and the related control group (CS). Results: Among the viral-related innate immune mediators, RIG1, LGP2, MAVS, STING, and DAI resulted well expressed in the bronchial and lung tissues of COPD patients, although not in a significantly different mode from control groups. Compared to CS, COPD patients showed no significant differences of viral load in bronchial rings and lung parenchyma. Conclusions: Some virus-related molecules are well-expressed in the lung tissue and bronchi of stable COPD patients independently of the disease severity, suggesting a "primed" tissue environment capable of sensing the potential viral infections occurring in these patients.

Oxidative and Nitrosative Stress in the Pathogenesis of Obstructive Lung Diseases of Increasing Severity.

The imbalance between increased oxidative agents and antioxidant defence mechanisms is central in the pathogenesis of obstructive lung diseases such as asthma and COPD. In these patients, there are increased levels of reactive oxygen species. Superoxide anions (O2 -), Hydrogen Peroxide (H2O2) and hydroxyl radicals (•OH) are critical for the formation of further cytotoxic radicals in the bronchi and lung parenchyma. Chronic inflammation, partly induced by oxidative stress, can further increase the oxidant burden through activated phagocytic cells (neutrophils, eosinophils, macrophages), particularly in severer disease states. Antioxidants and anti-inflammatory genes are, in fact, frequently downregulated in diseased patients. Nrf2, which activates the Antioxidant Response Element (ARE) leading to upregulation of GPx, thiol metabolism-associated detoxifying enzymes (GSTs) and stressresponse genes (HO-1) are all downregulated in animal models and patients with asthma and COPD. An exaggerated production of Nitric Oxide (NO) in the presence of oxidative stress can promote the formation of oxidizing reactive nitrogen species, such as peroxynitrite (ONO2 -), leading to nitration and DNA damage, inhibition of mitochondrial respiration, protein dysfunction, and cell damage in the biological systems. Protein nitration also occurs by activation of myeloperoxidase and H2O2, promoting oxidation of nitrite (NO2 -). There is increased nitrotyrosine and myeloperoxidase in the bronchi of COPD patients, particularly in severe disease. The decreased peroxynitrite inhibitory activity found in induced sputum of COPD patients correlates with pulmonary function. Markers of protein nitration - 3- nitrotyrosine, 3-bromotyrosine, and 3-chlorotyrosine - are increased in the bronchoalveolar lavage of severe asthmatics. Targeting the oxidative, nitrosative stress and associated lung inflammation through the use of either denitration mechanisms or new drug delivery strategies for antioxidant administration could improve the treatment of these chronic disabling obstructive lung diseases.