Respiratory Viral and Bacterial Exacerbations of COPD—The Role of the Airway Epithelium

Sputum SLC40A1 as a Novel Biomarker is Increased in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background

Solute carrier family 40 member 1 (SLC40A1 or Ferroportin) is a cell surface glycoprotein that participates in the efflux of cellular iron and disease pathogenesis. Induced sputum is a non-invasive method for lung sample collection. However, it remains unknown whether SLC40A1 is a potential diagnostic biomarker in induced sputum cells of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We in this study aimed to investigate the expression and the anti-inflammatory role of SLC40A1 in the induced-sputum cells of AECOPD patients.

Methods

A total of 35 induced sputum samples were collected from patients with AECOPD. Flow cytometry analysis was used to determine inflammatory cell phenotypes and SLC40A1 expression. Murine RAW 264.7 cell lines were treated with cigarette smoke extract (CSE) and SLC40A1-shRNA for SLC40A1 expression in vitro. ELISA was used for measurement of pro-inflammatory cytokine expression in vitro.

Results

Flow cytometry analysis showed that sputum neutrophils were increased in AECOPD patients with 3-5 exacerbations per year compared to 1 exacerbation per year, accompanied by elevated expression of CD40 and SLC40A1 in macrophages. The lung function (FEV1%pred) was reduced with a higher COPD exacerbation rate. There was a negative correlation between the FEV1% predicted and sputum neutrophil count. Patients expressing high levels of SLC40A1 exhibited higher exacerbation rates. SLC40A1 expression levels positively correlated with sputum neutrophils and negatively correlated with predicted FEV1%. In addition, mechanical ventilation reduces sputum neutrophils and SLC40A1 expression, particularly in patients with a high exacerbation rate. Further analysis in RAW 264.7 macrophage cell lines showed that cigarette smoke extract (CSE) increased the expression of SLC40A1, TNF-α, IL-6 and IL-10 at a concentration-dependent manner. SLC40A1 knockdown increased the expression of TNF-α and IL-6 and reduced the expression of IL-10 in CSE-treated macrophages.

Conclusion

SLC40A1 in sputum macrophages is increased and closely related to AECOPD severity, it would be a potential anti-inflammatory biomarker of patients with AECOPD.

Nebulized 2-deoxylated glucose analogues inhibit respiratory viral infection in advanced in vitro airway models

Respiratory viral infections, such as those caused by rhinoviruses (RVs) and human corona viruses (HCoV), result in a serious strain on healthcare systems and public health, underscoring an urgent need for inhaled broad-spectrum antiviral therapies. However, their development is challenging, as no standardized in vitro methodologies that can fully replicate the in vivo environment have been established. In this work, we aimed to investigate the antiviral and anti-inflammatory effect of three 2-deoxylated glucose analogues (2-DGA): 2-deoxy-D-glucose, 2-fluoro-2-deoxy-D-glucose and 2-fluoro-2-deoxy-D-mannose (2-FDM), by utilizing advanced in vitro air-liquid interface (ALI) airway models. We demonstrated that commonly used ALI models have variable susceptibility to RV, HCoV and influenza A virus (IAV) infection. Further, we showed that 2-DGA have an anti-inflammatory effect and suppress respiratory viral replication in models mimicking the upper and lower respiratory airways. Moreover, we confirmed that 2-DGA can be delivered via nebulization in vitro, highlighting their potential to be used as broad-spectrum inhaled antivirals. Finally, our results demonstrate the importance of incorporating complex in vitro methodologies, such as primary cell ALI cultures and aerosol exposure, at an early stage of drug development.

Physiology and pathophysiology of mucus and mucolytic use in critically ill patients

Airway mucus is a highly specialised secretory fluid which functions as a physical and immunological barrier to pathogens whilst lubricating the airways and humifying atmospheric air. Dysfunction is common during critical illness and is characterised by changes in production rate, chemical composition, physical properties, and inflammatory phenotype. Mucociliary clearance, which is determined in part by mucus characteristics and in part by ciliary function, is also dysfunctional in critical illness via disease related and iatrogenic mechanisms. The consequences of mucus dysfunction are potentially devastating, contributing to prolonged ventilator dependency, increased risk of secondary pneumonia, and worsened lung injury. Mucolytic therapies are designed to decrease viscosity, improve expectoration/suctioning, and thereby promote mucus removal. Mucolytics, including hypertonic saline, dornase alfa/rhDNase, nebulised heparin, carbocisteine/N-Acetyl cysteine, are commonly used in critically ill patients. This review summarises the physiology and pathophysiology of mucus and the existing evidence for the use of mucolytics in critically ill patients and speculates on journey to individualised mucolytic therapy.

Immunological Insights and Therapeutic Advances in COPD: Exploring Oral Bacterial Vaccines for Immune Modulation and Clinical Improvement

Chronic obstructive pulmonary disease (COPD) is a prevalent chronic condition associated with substantial global morbidity and mortality. Primarily caused by prolonged exposure to harmful agents such as dust and gases, COPD is characterized by persistent airflow limitation, clinically manifesting as chronic cough, sputum production, and dyspnea. The disease course alternates between stable phases and exacerbations, with the latter often associated with pathogenic colonization of the respiratory tract. This review examines the immunological underpinnings of COPD, emphasizing the interplay between innate and adaptive immunity in disease pathogenesis. Dysregulated immune responses to environmental factors perpetuate chronic inflammation, resulting in progressive pulmonary epithelial damage and connective tissue hyperplasia, which compromise gas exchange. Exacerbations further exacerbate respiratory failure, aggravating patient symptoms and accelerating disease progression. Despite advances in COPD management, effective therapeutic options remain limited. Current treatments primarily aim to alleviate symptoms, reduce immune activation, and manage infections, yet many patients experience suboptimal outcomes. This review highlights the potential of novel therapeutic approaches targeting immune system cells and pathways. In particular, it explores the promise of oral bacterial vaccines as immunomodulatory agents to enhance immune responses and improve clinical outcomes in COPD, addressing critical gaps in current treatment paradigms.

Therapeutic effects of Lianhua Qingke on COPD and influenza virus-induced exacerbation of COPD are associated with the inhibition of NF-κB signaling and NLRP3 inflammasome responses

Lianhua Qingke (LHQK), a traditional Chinese medicine (TCM) used clinically for the treatment of respiratory diseases with acute tracheobronchitis, and cough, has demonstrated promising efficacy in suppressing inflammation, inhibitingmucin secretion, reducing goblet cell hyperplasia andmaintainingairway epithelial integrity. However, its efficacy in managing chronic obstructive pulmonary disease (COPD) progression, particularly virus-induced acute exacerbations of COPD (AECOPD),remains unclear. Here, cigarette smoke (CS)-induced COPD and CS+virus (influenza H1N1)-triggered AECOPD mouse models were employed to evaluated the therapeutic potential of LHQK. The findings demonstrated that LHQK treatment led to significant improved pulmonary function, suppressed pulmonary inflammation, alleviated lung histopathological changes, and preserved airway epithelial integrity in COPD mice. Additionally, LHQK treatment effectively inhibited viral replication in the lungs of AECOPD mice and decreased recruitment of immune cells (M1 macrophages, progenitor-exhausted T cells and CD8 + T cells) to the lungs. Western blot analysis indicated that the therapeutic effects of LHQK are associated with the inhibition ofNF-κB signaling and NLRP3 inflammasome activation. Collectively, these findings elucidate the underlying mechanisms by which LHQK mitigates COPD and AECOPD, thereby supporting its potential as a therapeutic option for individuals afflicted with these conditions.

Physiological Assessment of ECCO2R on the Work of Breathing in Exacerbations of COPD

RATIONALE

The impact of extracorporeal carbon dioxide removal (ECCO2R) on work of breathing and aeration in exacerbations of chronic obstructive pulmonary disease (AECOPD) is poorly understood.

OBJECTIVES

The study explores the impact of non-invasive ventilation (NIV) and ECCO2R on respiratory drive, effort and distribution of ventilation in AECOPD.

METHODS

Patients enrolled in a randomised controlled study of the addition of ECCO2R to NIV compared with NIV underwent oesophageal pressure measurement, electrical impedance tomography and parasternal electromyography.

MEASUREMENTS AND MAIN RESULTS

18 patients were enrolled, nine in each arm. Of these, eight in the NIV arm and seven in the ECCO2R arm underwent physiological assessment. Patients randomised to ECCO2R, had a period of NIV combined with ECCO2R and, after removal of NIV, a period of ECCO2R alone. The removal of NIV whilst remaining on ECCO2R resulted in a respiratory acidosis (pH 7.34 (7.31-7.34) vs. 7.31 (7.31-7.34), p < 0.0001), increased work of breathing (7.43 (6.08-10.19) vs. 11.1 (8.11-15.15) J/min, p < 0.0001) and increased neural drive (884.4 (684.7-967.3) vs. 1321.1 (903.3-1575.3) AU, p = 0.0005). On day 1, the work of breathing was lower in the NIV than the ECCO2R group (4.38 (2.76-7.27) vs. 8.03 (4.8-15.94) J/min, p < 0.0001), minute ventilation was higher (15.54 (13.14-18.48) vs. 12.24 (8.51-13.9) L/min, p < 0.0001) and neural drive was the same (1,163.8 (1,085.5-1,325.5) vs. 1,093.8 (885.7-1,258.7) AU, p = 0.5556).

CONCLUSIONS

The combination of NIV and ECCO2R results in lower work of breathing and improved neuro-ventilatory coupling. NIV fully supports ventilation early whilst ECCO2R improves neuro-ventilatory coupling and work of breathing over time.

TRIAL REGISTRATION

Clinicaltrials.gov; NCT02086084; registered 1 December 2015; https://clinicaltrials.gov/study/NCT02086084?cond=copd&term=ecco2r&rank=4.

Alleviatory Role of Panax Notoginseng Saponins in Modulating Inflammation and Pulmonary Vascular Remodeling in Chronic Obstructive Pulmonary Disease: mechanisms and Implications

COPD is an inflammatory lung disease that limits airflow and remodels the pulmonary vascular system. This study delves into the therapeutic potential and mechanistic underpinnings of Panax notoginseng Saponins (PNS) in alleviating inflammation and pulmonary vascular remodeling in a COPD rat model. Symmap and ETCM databases provided Panax notoginseng-related target genes, and the CTD and DisGeNET databases provided COPD-related genes. Intersection genes were subjected to protein-protein interaction analysis and pathway enrichment to identify downstream pathways. A COPD rat model was established, with groups receiving varying doses of PNS and a Roxithromycin control. The pathological changes in lung tissue and vasculature were examined using histological staining, while molecular alterations were explored through ELISA, RT-PCR, and Western blot. Network pharmacology research suggested PNS may affect the TLR4/NF-κB pathway linked to COPD development. The study revealed that, in contrast to the control group, the COPD model exhibited a significant increase in inflammatory markers and pathway components such as TLR4, NF-κB, HIF-1α, VEGF, ICAM-1, SELE mRNA, and serum TNF-α, IL-8, and IL-1β. Treatment with PNS notably decreased these markers and mitigated inflammation around the bronchi and vessels. Taken together, the study underscores the potential of PNS in reducing lung inflammation and vascular remodeling in COPD rats, primarily via modulation of the TLR4/NF-κB/HIF-1α/VEGF pathway. This research offers valuable insights for developing new therapeutic strategies for managing and preventing COPD.

Influenza and pneumococcal vaccination in patients with COPD from 3 French cohorts: Insufficient coverage and associated factors

BACKGROUND

Low vaccination rates against influenza and Streptococcus (S.) pneumoniae infections in COPD could impair outcomes. Understanding underlying factors could help improving implementation.

OBJECTIVES

To describe vaccination rates at inclusion in COPD cohorts and analyze associated factors.

METHODS

Between 2012 and 2018, 5927 patients with sufficient data available were recruited in 3 French COPD cohorts (2566 in COLIBRI-COPD, 2653 in PALOMB and 708 in Initiatives BPCO). Data at inclusion were pooled to describe vaccination rates and analyze associated factors.

RESULTS

Mean age was 66 years, 34 % were women, 35 % were current smokers, mean FEV1 was 58 % predicted, 22 % reported ≥2 exacerbations in the year prior to inclusion, mMRC dyspnea grade was ≥2 in 59 %, 52 % had cardiovascular comorbidities and 9 % a history of asthma. Vaccinations rates in the year prior to study entry were 34.4 % for influenza + S. pneumoniae, 17.5 % for influenza alone and 8.9 % for S. pneumoniae alone. In multivariate analyses, influenza vaccination rate was greater in older age, smoking status, low FEV1, exacerbation history, mMRC dyspnea>2, asthma history, hypertension, diabetes mellitus, and the year of inclusion. SP vaccination was associated with type of practice of the respiratory physician, age, smoking status, FEV1, exacerbation history, dyspnea grade, asthma history and the year of inclusion.

CONCLUSION

Rates of vaccination against influenza and S. pneumoniae infection at inclusion in COPD cohorts remain insufficient and vaccination appears restricted to patients with specific features especially regarding severity and comorbidities, which is not consistent with current recommendations.

Is There a Role for Immunostimulant Bacterial Lysates in the Management of Respiratory Tract Infection?

Bacterial Lysates are immunostimulants clinically prescribed for the prevention of respiratory tract infections (RTIs). It has been shown that Bacterial Lysates upregulate the immune system, acting both on innate and adaptive reactions. In fact, there are demonstrations of their efficacy in restoring the integrity and immune function of epithelial barriers, activating ILC3 and dendritic cells with an enhanced Th1 response, and producing serum IgG and serum and salivary IgA specific to the administered bacterial antigens. The activated immune system also protects against other bacteria and viruses due to a trained immunity effect. Most studies show that the number of RTIs and their severity decrease in Bacterial Lysates-pretreated patients, without relevant side effects. The Bacterial Lysates treatment, in addition to reducing the number of RTIs, also prevents the deterioration of the underlying disease (i.e., COPD) induced by repeated infections. Despite these positive data, the most recent meta-analyses evidence the weakness of the studies performed, which are of low quality and have an inadequate number of patients, some of which were non-randomized while others were without a control group or were performed contemporarily in different clinical conditions or with different ages. The high heterogeneity of the studies does not allow us to state Bacterial Lysates' effectiveness in preventing RTIs with sufficient certainty. To completely define their indications, double-blind, placebo-controlled, multicenter, randomized clinical trials should be performed for each product and for each indication. The study population should be adequate for each indication. For this purpose, an adequate run-in phase will be necessary.

Role of airway epithelium in viral respiratory infections: Can carbocysteine prevent or mitigate them?

Alterations in airway epithelial homeostasis increase viral respiratory infections risk. Viral infections frequently are associated with chronic obstructive pulmonary disease (COPD) exacerbations, events that dramatically promote disease progression. Mechanism promoting the main respiratory viruses entry and virus-evocated innate and adaptive immune responses have now been elucidated, and an oxidative stress central role in these pathogenic processes has been recognized. Presence of reactive oxygen species in macrophages and other cells allows them to eliminate virus, but its excess alters the balance between innate and adaptive immune responses and proteases/anti-proteases and leads to uncontrolled inflammation, tissue damage, and hypercoagulability. Different upper and lower airway cell types also play a role in viral entry and infection. Carbocysteine is a muco-active drug with anti-oxidant and anti-inflammatory properties used for the management of several chronic respiratory diseases. Although the use of anti-oxidants has been proposed as an effective strategy in COPD exacerbations management, the molecular mechanisms that explain carbocysteine efficacy have not yet been fully clarified. The present review describes the most relevant features of the common respiratory virus pathophysiology with a focus on epithelial cells and oxidative stress role and reports data supporting a putative role of carbocysteine in viral respiratory infections.

Lianhua Qingke Preserves Mucociliary Clearance in Rat with Acute Exacerbation of Chronic Obstructive Pulmonary Disease by Maintaining Ciliated Cells Proportion and Protecting Structural Integrity and Beat Function of Cilia

Purpose

Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) is a sudden worsening of symptoms in patients with Chronic Obstructive Pulmonary Disease (COPD), such as cough, increased sputum volume, and sputum purulence. COPD and AECOPD are characterized by damage to cilia and increased mucus secretion. Mucociliary clearance (MCC) functions as part of the primary innate system of the lung to remove harmful particles and pathogens together with airway mucus and is therefore crucial for patients with COPD.

Methods

AECOPD was induced by cigarette smoke exposure (80 cigarettes/day, 5 days/week for 12 weeks) and lipopolysaccharide (LPS) instillation (200 μg, on days 1, 14, and 84). Rats administered Lianhua Qingke (LHQK) (0.367, 0.732, and 1.465 g/kg/d) or Eucalyptol, Limonene, and Pinene Enteric Soft Capsules (ELP, 0.3 g/kg/d) intragastrically. Pulmonary pathology, Muc5ac+ goblet cell and β-tubulin IV+ ciliated cells, and mRNA levels of forkhead box J1 (Foxj1) and multiciliate differentiation and DNA synthesis associated cell cycle protein (MCIDAS) were assessed by hematoxylin and eosin staining, immunofluorescence staining, and RT-qPCR, respectively. Ciliary morphology and ultrastructure were examined through scanning electron microscopy and transmission electron microscopy. Ciliary beat frequency (CBF) was recorded using a high-speed camera.

Results

Compared to the model group, LHQK treatment groups showed a reduction in inflammatory cell infiltration, significantly reduced goblet cell and increased ciliated cell proportion. LHQK significantly upregulated mRNA levels of MCIDAS and Foxj1, indicating promoted ciliated cell differentiation. LHQK protected ciliary structure and maintained ciliary function via increasing the ciliary length and density, reducing ciliary ultrastructure damage, and ameliorating random ciliary oscillations, consequently enhancing CBF.

Conclusion

LHQK enhances the MCC capability of ciliated cells in rat with AECOPD by preserving the structural integrity and beating function of cilia, indicating its therapeutic potential on promoting sputum expulsion in patients with AECOPD.

Breathlessness and "exacerbation" questions predictive for incident COPD (MARKO study): data after two years of follow-up

Aims

To determine the predictability of the MARKO questionnaire and/or its domains, individually or in combination with other markers and characteristics (age, gender, smoking history, lung function, 6-min walk test (6 MWT), exhaled breath temperature (EBT), and hsCRP for the incident chronic obstructive pulmonary disease (COPD) in subjects at risk over 2 years follow-up period).

Participants and Methods

Patients, smokers/ex-smokers with >20 pack-years, aged 40-65 years of both sexes were recruited and followed for 2 years. After recruitment and signing the informed consent at the GP, a detailed diagnostic workout was done by the pulmonologist; they completed three self-assessment questionnaires-MARKO, SGRQ and CAT, detailed history and physical, laboratory (CBC, hsCRP), lung function tests with bronchodilator and EBT. At the 2 year follow-up visit they performed: the same three self-assessment questionnaires, history and physical, lung function tests and EBT.

Results

A sample of 320 subjects (41.9% male), mean (SD) age 51.9 (7.4) years with 36.4 (17.4) pack-years of smoking was reassessed after 2.1 years. Exploratory factor analysis of MARKO questionnaire isolated three distinct domains (breathlessness and fatigue, "exacerbations", cough and expectorations). We have determined a rate for incident COPD that was 4.911/100 person-years (95% CI [3.436-6.816]). We found out that questions about breathlessness and "exacerbations", and male sex were predictive of incident COPD after two years follow-up (AUC 0.79, 95% CI [0.74-0.84], p < 0.001). When only active smokers were analyzed a change in EBT after a cigarette (ΔEBT) was added to a previous model (AUC 0.83, 95% CI [0.78-0.88], p < 0.001).

Conclusion

Our preliminary data shows that the MARKO questionnaire combined with EBT (change after a cigarette smoke) could potentially serve as early markers of future COPD in smokers.

The effect of bradykinin 1 receptor antagonist BI 1026706 on pulmonary inflammation after segmental lipopolysaccharide challenge in healthy smokers

BACKGROUND

Bradykinin 1 receptor (B1R) signalling pathways may be involved in the inflammatory pathophysiology of chronic obstructive pulmonary disease (COPD). B1R signalling is induced by inflammatory stimuli or tissue injury and leads to activation and increased migration of pro-inflammatory cells. Lipopolysaccharide (LPS) lung challenge in man is an experimental method of exploring inflammation in the lung whereby interference in these pathways can help to assess pharmacologic interventions in COPD. BI 1026706, a potent B1R antagonist, was hypothesized to reduce the inflammatory activity after segmental lipopolysaccharide (LPS) challenge in humans due to decreased pulmonary cell influx.

METHODS

In a monocentric, randomized, double-blind, placebo-controlled, parallel-group, phase I trial, 57 healthy, smoking subjects were treated for 28 days with either oral BI 1026706 100 mg bid or placebo. At day 21, turbo-inversion recovery magnitude magnetic resonance imaging (TIRM MRI) was performed. On the last day of treatment, pre-challenge bronchoalveolar lavage fluid (BAL) and biopsies were sampled, followed by segmental LPS challenge (40 endotoxin units/kg body weight) and saline control instillation in different lung lobes. Twenty-four hours later, TIRM MRI was performed, then BAL and biopsies were collected from the challenged segments. In BAL samples, cells were differentiated for neutrophil numbers as the primary endpoint. Other endpoints included assessment of safety, biomarkers in BAL (e.g. interleukin-8 [IL-8], albumin and total protein), B1R expression in lung biopsies and TIRM score by MRI as a measure for the extent of pulmonary oedema.

RESULTS

After LPS, but not after saline, high numbers of inflammatory cells, predominantly neutrophils were observed in the airways. IL-8, albumin and total protein were also increased in BAL samples after LPS challenge as compared with saline control. There were no significant differences in cells or other biomarkers from BAL in volunteers treated with BI 1026706 compared with those treated with placebo. Unexpectedly, neutrophil numbers in BAL were 30% higher and MRI-derived extent of oedema was significantly higher with BI 1026706 treatment compared with placebo, 24 h after LPS challenge. Adverse events were mainly mild to moderate and not different between treatment groups.

CONCLUSIONS

Treatment with BI 1026706 for four weeks was safe and well-tolerated in healthy smoking subjects. BI 1026706 100 mg bid did not provide evidence for anti-inflammatory effects in the human bronchial LPS challenge model.

TRIAL REGISTRATION

The study was registered on January 14, 2016 at ClinicalTrials.gov (NCT02657408).

Pneumocystis Exacerbates Inflammation and Mucus Hypersecretion in a Murine, Elastase-Induced-COPD Model

Inflammation and mucus hypersecretion are frequent pathology features of chronic respiratory diseases such as asthma and COPD. Selected bacteria, viruses and fungi may synergize as co-factors in aggravating disease by activating pathways that are able to induce airway pathology. Pneumocystis infection induces inflammation and mucus hypersecretion in immune competent and compromised humans and animals. This fungus is a frequent colonizer in patients with COPD. Therefore, it becomes essential to identify whether it has a role in aggravating COPD severity. This work used an elastase-induced COPD model to evaluate the role of Pneumocystis in the exacerbation of pathology, including COPD-like lung lesions, inflammation and mucus hypersecretion. Animals infected with Pneumocystis developed increased histology features of COPD, inflammatory cuffs around airways and lung vasculature plus mucus hypersecretion. Pneumocystis induced a synergic increment in levels of inflammation markers (Cxcl2, IL6, IL8 and IL10) and mucins (Muc5ac/Muc5b). Levels of STAT6-dependent transcription factors Gata3, FoxA3 and Spdef were also synergically increased in Pneumocystis infected animals and elastase-induced COPD, while the levels of the mucous cell-hyperplasia transcription factor FoxA2 were decreased compared to the other groups. Results document that Pneumocystis is a co-factor for disease severity in this elastase-induced-COPD model and highlight the relevance of STAT6 pathway in Pneumocystis pathogenesis.

COPD Exacerbation-Related Pathogens and Previous COPD Treatment

We evaluated whether the pathogens identified during acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) are associated with the COPD medications used in the 6 months before AE-COPD. We collected the medical records of patients diagnosed with AE-COPD at 28 hospitals between January 2008 and December 2019 and retrospectively analyzed them. Microorganisms identified at the time of AE-COPD were analyzed according to the use of inhaled corticosteroid (ICS) and systemic steroid after adjusting for COPD severity. We evaluated 1177 patients with AE-COPD and available medication history. The mean age of the patients was 73.9 ± 9.2 years, and 83% were males. The most frequently identified bacteria during AE-COPD were Pseudomonas aeruginosa (10%), followed by Mycoplasma pneumoniae (9.4%), and Streptococcus pneumoniae (5.1%), whereas the most commonly identified viruses were rhinovirus (11%) and influenza A (11%). During AE-COPD, bacteria were more frequently identified in the ICS than non-ICS group (p = 0.009), and in the systemic steroid than non-systemic steroid group (p < 0.001). In patients who used systemic steroids before AE-COPD, the risk of detecting Pseudomonas aeruginosa was significantly higher during AE-COPD (OR 1.619, CI 1.007−2.603, p = 0.047), but ICS use did not increase the risk of Pseudomonas detection. The risk of respiratory syncytial virus (RSV) detection was low when ICS was used (OR 0.492, CI 0.244−0.988, p = 0.045). COPD patients who used ICS had a lower rate of RSV infection and similar rate of P. aeruginosa infection during AE-COPD compared to patients who did not use ICS. However, COPD patients who used systemic steroids within 6 months before AE-COPD had an increased risk of P. aeruginosa infection. Therefore, anti-pseudomonal antibiotics should be considered in patients with AE-COPD who have used systemic steroids.

Effect of Macrolide Antibiotics on In-Hospital Mortality Among Acute Exacerbation of COPD Patients: A Propensity Score-Matched Analysis

Objective

This study aimed to assess whether the short-term use of macrolide antibiotics during hospitalization can reduce in-hospital all-cause mortality compared to non-macrolide treatment in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

A propensity score (PS) matching analysis was performed using retrospective data from the admission records of AECOPD patients in the medical general ward and medical intensive care unit of a tertiary care center between October 2015 and September 2018. The multivariable Cox proportional hazard model was performed to eliminate residual confounding after the PS analysis.

Results

The mortality rate was 11.1% of 1528 admissions in the PS matching cohort. Approximately 70% of patients had respiratory failure requiring intubation on initial admission, and 34% had pneumonia. Macrolide treatment significantly reduced in-hospital mortality among AECOPD patients (adjusted hazard ratio, 0.55; 95% confidence interval 0.32–0.96; P=0.034). Clarithromycin was the most commonly prescribed macrolide (80%).

Conclusion

Macrolide antibiotics reduced in-hospital mortality in hospitalized AECOPD patients. The combination of antimicrobial and immunomodulatory effects of macrolide treatment could play an essential role.

In Vivo and In Vitro Studies of Cigarette Smoke Effects on Innate Responses to Influenza Virus: A Matter of Models?

Cigarette smoke (CS) is a significant public health problem and a leading risk factor for the development of chronic obstructive pulmonary disease (COPD) in the developed world. Respiratory viral infections, such as the influenza A virus (IAV), are associated with acute exacerbations of COPD and are more severe in cigarette smokers. To fight against viral infection, the host has developed an innate immune system, which has complicated mechanisms regulating the expression and activation of cytokines and chemokines to maximize the innate and adaptive antiviral response, as well as limiting the immunopathology that leads to exaggerated lung damage. In the case of IAV, responders include airway and alveolar epithelia, lung macrophages and dendritic cells. To achieve a successful infection, IAV must overcome these defenses. In this review, we summarize the detrimental role of CS in influenza infections. This includes both immunosuppressive and proinflammatory effects on innate immune responses during IAV infection. Some of the results, with respect to CS effects in mouse models, appear to have discordant results, which could be at least partially addressed by standardization of animal viral infection models to evaluate the effect of CS exposure in this context.