Bacterial-viral load and the immune response in stable and exacerbated COPD: significance and therapeutic prospects

The use of antibiotics in the early stage of acute exacerbation of chronic obstructive pulmonary disease in patients without obvious signs of infection: a multicenter, randomized, parallel-controlled study

Introduction

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease with high prevalence and mortality. In some acute exacerbations of COPD (AECOPD) in patients with no obvious signs of infection, early antibiotic treatment seems to clinically improve the disease, but more studies are needed to determine the prognostic impact of antibiotic treatment in AECOPD patients with no obvious signs of infection.

Purpose

To clarify the impact of antibiotic treatment on the short-term and long-term prognoses of AECOPD patients without obvious signs of infection.

Methods

The impact of the two treatment methods on the prognosis of patients was compared at 30, 90, 180, and 360 days after discharge. A multicenter, randomized, parallel-controlled clinical trial was conducted in a department of respiratory and critical care medicine in Central China. All patients met the inclusion criteria for AECOPD, and the patients were randomly assigned to the antibiotic group or the nonantibiotic group at a 1:1 ratio. Patients in the antibiotic group were given moxifloxacin 400 mg/day intravenously for 7 days. Patients in the nonantibiotic group were intravenously injected with the same amount of normal saline as the amount of moxifloxacin given to those in the antibiotic group for 7 days.

Results

There were 406 patients in the antibiotic group and 410 patients in the nonantibiotic group. During the short-term and long-term follow-ups, the acute exacerbation frequency, intensive care unit (ICU) treatment rate, mortality, and mMRC and CAT scores were not significantly different between the two groups (p > 0.05). At the 180- and 360-day follow-ups, the forced expiratory volume in 1 s (FEV1%) and peak expiratory flow (PEF) were not significantly different between the two groups (p > 0.05). The 30-day readmission rate was significantly lower in the antibiotic group than in the nonantibiotic group (p < 0.05). The time from discharge to the first acute exacerbation was not significantly different between the two groups (p > 0.05). The length of the first hospital stay after discharge was significantly lower in the antibiotic group (5.84 days) than in the nonantibiotic group (6.75 days) (p < 0.05). At the 30-day follow-up, the acute exacerbation frequency, age, C-reactive protein (CRP) level, and sputum viscosity were significantly greater in the nonantibiotic group than in the antibiotic group (p < 0.05). In addition, according to the receiver operating characteristic (ROC) analysis, the frequency of acute exacerbations at the 30-day follow-up was significantly greater in COPD patients aged >62.5 years, with a CRP level >12.56 mg/L or with a sputum viscosity >III, in the nonantibiotic group than in those in the antibiotic group, suggesting that the short-term prognosis was poor.

Conclusion

Patients who are >62.5 years of age, have a CRP concentration >12.56 mg/L, or have a sputum viscosity >III without obvious signs of infection should be treated with antibiotics to improve their short-term prognosis.

Clinical Trial Registration

(https://www.chictr.org.cn), (ChiCTR1800018921).

Airway microbiome-immune crosstalk in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) has significantly contributed to global mortality, with three million deaths reported annually. This impact is expected to increase over the next 40 years, with approximately 5 million people predicted to succumb to COPD-related deaths annually. Immune mechanisms driving disease progression have not been fully elucidated. Airway microbiota have been implicated. However, it is still unclear how changes in the airway microbiome drive persistent immune activation and consequent lung damage. Mechanisms mediating microbiome-immune crosstalk in the airways remain unclear. In this review, we examine how dysbiosis mediates airway inflammation in COPD. We give a detailed account of how airway commensal bacteria interact with the mucosal innate and adaptive immune system to regulate immune responses in healthy or diseased airways. Immune-phenotyping airway microbiota could advance COPD immunotherapeutics and identify key open questions that future research must address to further such translation.

Caveolin-1 Promotes the Imbalance of Th17/Treg in Chronic Obstructive Pulmonary Disease by Regulating Hsp70 Expression

Objective

To investigate whether the expression of Hsp70 is associated with Cav-1 in promoting the imbalance of Th17/Treg cells in COPD.

Methods

The plasma Cav-1, Hsp70 expression were quantified by enzyme-linked immunosorbent assay (ELISA). The frequencies of circulating Th17, Treg cells and Th17/Treg ratio were determined by flow cytometry. Peripheral blood mononuclear cells (PBMCs) from subjects were transfected with Cav-1 or control plasmids and Hsp70 plasmid.

Results

We found that Cav-1 expression was lower but the levels of Hsp70 and Th17 cells were higher in COPD than in healthy control (HC). Hsp70 expressions were positively correlated with Cav-1 levels, Th17 cells, and Th17/Treg ratio in COPD but not in HC. Cav-1 over-expression resulted in an increase in Hsp70 and Th17 levels. Suppressing Hsp70 expressing by small interfering RNA (siRNA), the decline of Th17 frequency was observed in Cav-1-overexpressed PBMCs.

Conclusion

Collectively, our results illuminate that Cav-1 contributes to the imbalance of Th17/Treg through potentially regulating Hsp70 expression.

Airway pathogens detected in stable and exacerbated COPD in patients in Asia-Pacific

Background

The burden of chronic obstructive pulmonary disease (COPD) in the Asia-Pacific region is projected to increase. Data from other regions show bacterial and viral infections can trigger acute exacerbations of COPD (AECOPD).

Methods

This 1-year prospective epidemiological study (ClinicalTrials.gov identifier: NCT03151395) of patients with moderate to very severe COPD in Hong Kong, the Philippines, South Korea and Taiwan assessed the prevalence in sputum samples (by culture and PCR) of bacterial and viral pathogens during stable COPD and AECOPD. The odds of experiencing an exacerbation was evaluated for pathogen presence, acquisition and apparition. Health-related quality of life (HRQOL) was assessed.

Results

197 patients provided 983 sputum samples, with 226 provided during exacerbation episodes. The mean yearly AECOPD incidence rate was 1.27 per patient. The most prevalent bacteria by PCR at exacerbation were Haemophilus influenzae (Hi) and Moraxella catarrhalis (Mcat); Mcat prevalence was higher at exacerbation than at stable state. Virus prevalence was low, other than for human rhinovirus (HRV) (8.1%, stable state; 16.6%, exacerbation). The odds ratio (95% CI) for an exacerbation (versus stable state) was statistically significant for the presence, acquisition and apparition of Hi (2.20, 1.26–3.89; 2.43, 1.11–5.35; 2.32, 1.20–4.46, respectively), Mcat (2.24, 1.30–3.88; 5.47, 2.16–13.86; 3.45, 1.71–6.98, respectively) and HRV (2.12, 1.15–3.91; 2.22, 1.09–4.54; 2.09, 1.11–3.91, respectively). HRQOL deteriorated according to the number of exacerbations experienced.

Conclusion

In patients with COPD in the Asia-Pacific region, the presence of Hi, Mcat or HRV in sputum samples significantly increased the odds of an exacerbation, providing further evidence of potential roles in triggering AECOPD.

The presence of Haemophilus influenzae, Moraxella catarrhalis or human rhinovirus in sputum samples significantly increases the odds of an exacerbation, as opposed to being in stable state, in COPDhttps://bit.ly/39vI3XU

Mortality, seasonal variation, and susceptibility to acute exacerbation of COPD in the pandemic year: a nationwide population study

Background:

Previous studies have suggested that the coronavirus disease 2019 (COVID-19) pandemic was associated with a decreased rate of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Data on how the COVID-19 pandemic has influenced mortality, seasonality of, and susceptibility to AECOPD in the chronic obstructive pulmonary disease (COPD) population is scarce.

Methods:

We conducted a national population-based retrospective study using data from the Health Insurance Institute of Slovenia from 2015 to February 2021, with 2015–2019 as the reference. We extracted patient and healthcare data for AECOPD, dividing AECOPD into severe, resulting in hospitalisation, and moderate, requiring outpatient care. The national COPD population was generated based on dispensed prescriptions of inhalation therapies, and moderate AECOPD events were analysed based on dispensed AECOPD medications. We extracted data on all-cause and non-COVID mortality.

Results:

The numbers of severe and moderate AECOPD were reduced by 48% and 34%, respectively, in 2020. In the pandemic year, the seasonality of AECOPD was reversed, with a 1.5-fold higher number of severe AECOPD in summer compared to winter. The proportion of frequent exacerbators (⩾2 AECOPD hospitalisations per year) was reduced by 9% in 2020, with a 30% reduction in repeated severe AECOPD in frequent exacerbators and a 34% reduction in persistent frequent exacerbators (⩾2 AECOPD hospitalisations per year for 2 consecutive years) from 2019. The risk of two or more moderate AECOPD decreased by 43% in 2020. In the multivariate model, pandemic year follow-up was the only independent factor associated with a decreased risk for severe AECOPD (hazard ratio [HR]: 0.71; 95% confidence interval [CI]: 0.61–0.84; p < 0.0001). In 2020, non-COVID mortality decreased (−15%) and no excessive mortality was observed in the COPD population.

Conclusion:

In the pandemic year, we found decreased susceptibility to AECOPD across severity spectrum of COPD, reversed seasonal distribution of severe AECOPD and decreased non-COVID mortality in the COPD population.

Patient-Centered Discussion on End-of-Life Care for Patients with Advanced COPD

Exacerbations of chronic obstructive pulmonary disease (COPD) may lead to a rapid decline in health and subsequent death, an unfortunate tyranny of having COPD-an irreversible health condition of 16 million individuals in the USA totaling 60 million in the world. While COPD is the third largest leading cause of death, causing 3.23 million deaths worldwide in 2019 (according to the WHO), most patients with COPD do not receive adequate treatment at the end stages of life. Although death is inevitable, the trajectory towards end-of-life is less predictable in severe COPD. Thus, clinician-patient discussion for end-of-life and palliative care could bring a meaningful life-prospective to patients with advanced COPD. Here, we summarized the current understanding and treatment of COPD. This review also highlights the importance of patient-centered discussion and summarizes current status of managing patients with advanced COPD.

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.

Lung microbiome of stable and exacerbated COPD patients in Tshwane, South Africa

Chronic obstructive pulmonary disease (COPD) is characterised by the occurrence of exacerbations triggered by infections. The aim of this study was to determine the composition of the lung microbiome and lung virome in patients with COPD in an African setting and to compare their composition between the stable and exacerbated states. Twenty-four adult COPD patients were recruited from three hospitals. Sputum was collected and bacterial DNA was extracted. Targeted metagenomics was performed to determine the microbiome composition. Viral DNA and RNA were extracted from selected samples followed by cDNA conversion. Shotgun metagenomics sequencing was performed on pooled DNA and RNA. The most abundant phyla across all samples were Firmicutes and Proteobacteria. The following genera were most prevalent: Haemophilus and Streptococcus. There were no considerable differences for alpha and beta diversity measures between the disease states. However, a difference in the abundances between disease states was observed for: (i) Serratia (3% lower abundance in exacerbated state), (ii) Granulicatella (2.2% higher abundance in exacerbated state), (iii) Haemophilus (5.7% higher abundance in exacerbated state) and (iv) Veillonella (2.5% higher abundance in exacerbated state). Virome analysis showed a high abundance of the BeAn 58058 virus, a member of the Poxviridae family, in all six samples (90% to 94%). This study is among the first to report lung microbiome composition in COPD patients from Africa. In this small sample set, no differences in alpha or beta diversity between stable and exacerbated disease state was observed, but an unexpectedly high frequency of BeAn 58058 virus was observed. These observations highlight the need for further research of the lung microbiome of COPD patients in African settings.

Role of Toll-Like Receptor 2 in Regulation of T-Helper Immune Response in Chronic Obstructive Pulmonary Disease

Objective

According to modern views, the differences in the clinical course of chronic obstructive pulmonary disease (COPD) are associated with certain types of T-helper (Th) immune response. Recent data have shown that toll-like receptor 2 (TLR2) is involved in the development of Th immune response. However, TLR2-mediated regulation of Th subpopulation balance in COPD needs to be elucidated. The aim of our work is to determine the mechanisms of TLR2-mediated regulation of Th immune response in COPD of varying severity.

Methods

The study included 323 smokers/ex-smokers with stable COPD (GOLD I, GOLD II, and GOLD III) and 97 healthy nonsmokers (control group). Serum levels of Th1 (TNF-α and IFN-γ), Th2 (IL-4), Th17 (IL-6 and IL-17A), Treg (IL-10) cytokines, and the percentage of peripheral blood Th cells expressing TLR2 (CD4⁺CD282⁺) were assessed by flow cytometry. Serum concentrations of IL-21 (Th17) and TGF-β1 (Treg) were measured using the ELISA method. The predominant Th cytokine profile in serum was determined by calculating the ratios between levels of Th1 and Th17 cytokines. Spearman's correlation test was performed.

Results

Patients with COPD GOLD II and III with Th1 and Th17 cytokine profiles exhibited an increase in the percentage of CD4⁺CD282⁺ cells compared to the control group. In COPD GOLD I–III, positive correlations between CD4⁺CD282⁺ cell frequency and Th17 cytokine levels (IL-6, IL-17A, and IL-21) were found. In COPD GOLD I, IL-10 concentration was negatively correlated with the percentages of studied cells; in COPD GOLD II, a positive correlation between these parameters was noted.

Conclusions

Enhanced TLR2 expression on CD4⁺ cells shifts cytokine profile toward Th17 phenotype that plays a crucial role in COPD progression. The level of TLR2 expression on peripheral blood CD4⁺ cells may be considered as a biomarker for diagnosing and predicting the progression of COPD.

Phenotyping acute exacerbation of COPD: what more can we do for hospitalised patients?

Hospitalised #AECOPD are characterised by multiple facets of aetiology. The clinical interpretation of the composite phenotypes of AECOPD and the robustness of the AECOPD phenotype need to be discussed further. https://bit.ly/3grzQEO.

Participation of ABCA1 Transporter in Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is the important medical and social problem. According to modern concepts, COPD is a chronic inflammatory disease, macrophages play a key role in its pathogenesis. Macrophages are heterogeneous in their functions, which is largely determined by their immunometabolic profile, as well as the features of lipid homeostasis, in which the ATP binding cassette transporter A1 (ABCA1) plays an essential role. The objective of this work is the analysis of the ABCA1 protein participation and the function of reverse cholesterol transport in the pathogenesis of COPD. The expression of the ABCA1 gene in lung tissues takes the second place after the liver, which indicates the important role of the carrier in lung function. The participation of the transporter in the development of COPD consists in provision of lipid metabolism, regulation of inflammation, phagocytosis, and apoptosis. Violation of the processes in which ABCA1 is involved may be a part of the pathophysiological mechanisms, leading to the formation of a heterogeneous clinical course of the disease.

Interactions of Bacteriophages and Bacteria at the Airway Mucosa: New Insights Into the Pathophysiology of Asthma

The airway epithelium is the primary site where inhaled and resident microbiota interacts between themselves and the host, potentially playing an important role on allergic asthma development and pathophysiology. With the advent of culture independent molecular techniques and high throughput technologies, the complex composition and diversity of bacterial communities of the airways has been well-documented and the notion of the lungs' sterility definitively rejected. Recent studies indicate that the microbial composition of the asthmatic airways across the spectrum of disease severity, differ significantly compared with healthy individuals. In parallel, a growing body of evidence suggests that bacterial viruses (bacteriophages or simply phages), regulating bacterial populations, are present in almost every niche of the human body and can also interact directly with the eukaryotic cells. The triptych of airway epithelial cells, bacterial symbionts and resident phages should be considered as a functional and interdependent unit with direct implications on the respiratory and overall homeostasis. While the role of epithelial cells in asthma pathophysiology is well-established, the tripartite interactions between epithelial cells, bacteria and phages should be scrutinized, both to better understand asthma as a system disorder and to explore potential interventions.

Power Outage: An Ignored Risk Factor for COPD Exacerbations

BACKGROUND

COPD is the third leading cause of death in the United States, with 16 million Americans currently experiencing difficulty with breathing. Power outages could be life-threatening for those relying on electricity. However, significant gaps remain in understanding the potential impact of power outages on COPD exacerbations.

RESEARCH QUESTION

The goal of this study was to determine how power outages affect COPD exacerbations.

STUDY DESIGN AND METHODS

Using distributed lag nonlinear models controlling for time-varying confounders, the hospitalization rate during a power outage was compared vs non-outage periods to determine the rate ratio (RR) for COPD and its subtypes at each of 0 to 6 lag days in New York State from 2001 to 2013. Stratified analyses were conducted according to sociodemographic characteristics, season, and clinical severity; changes were investigated in numerous critical medical indicators, including length of stay, hospital cost, the number of comorbidities, and therapeutic procedures between the two periods.

RESULTS

The RR of COPD hospitalization following power outages ranged from 1.03 to 1.39 across lag days. The risk was strongest at lag0 and lag1 days and lasted significantly for 7 days. Associations were stronger for the subgroup with acute bronchitis (RR, 1.08-1.69) than for cases of acute exacerbation (RR, 1.03-1.40). Compared with non-outage periods, the outage period was observed to be $4.67 thousand greater in hospital cost and 1.38 greater in the number of comorbidities per case. The average cost (or number of comorbidities) was elevated in all groups stratified according to cost (or number of comorbidities). In contrast, changes in the average length of stay (-0.43 day) and the average number of therapeutic procedures (-0.09) were subtle.

INTERPRETATION

Power outages were associated with a significantly elevated rate of COPD hospitalization, as well as greater costs and number of comorbidities. The average cost and number of comorbidities were elevated in all clinical severity groups.

The Role of Toll-Like Receptors 2 and 4 in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Currently, chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide. The determination of immune mechanisms of inflammation in the disease presents an important challenge for fundamental medical research. According to modern views, Toll-like receptors (TLRs), among which TLR2 and TLR4 play a key role, are one of the essential components of inflammatory process in COPD. This review focuses on following aspects: the role of TLR2 and TLR4 in the initiation of inflammatory process in COPD; the mechanisms of influence of various exogenous factors (cigarette smoke, suspended particulate matter, and bacteria) on the expression of TLR2 and TLR4; the contribution of these TLRs to the T-helper (Th) immune response development in COPD, in particular to the Th17 immune response, which contributes to the progression of the disease and therapeutic implications of TLR2 and TLR4 in COPD.

How Do Innate Immune Cells Contribute to Airway Remodeling in COPD Progression?

Recently, the therapeutic potential of immune-modulation during the progression of chronic obstructive pulmonary disease (COPD) has been attracting increasing interest. However, chronic inflammatory response has been over-simplified in descriptions of the mechanism of COPD progression. As a form of first-line airway defense, epithelial cells exhibit phenotypic alteration, and participate in epithelial layer disorganization, mucus hypersecretion, and extracellular matrix deposition. Dendritic cells (DCs) exhibit attenuated antigen-presenting capacity in patients with advanced COPD. Immature DCs migrate into small airways, where they promote a pro-inflammatory microenvironment and bacterial colonization. In response to damage-associated molecular patterns (DAMPs) in lung tissue affected by COPD, neutrophils are excessively recruited and activated, where they promote a proteolytic microenvironment and fibrotic repair in small airways. Macrophages exhibit decreased phagocytosis in the large airways, while they demonstrate high pro-inflammatory potential in the small airways, and mediate alveolar destruction and chronic airway inflammation. Natural killer T (NKT) cells, eosinophils, and mast cells also play supplementary roles in COPD progression; however, their cellular activities are not yet entirely clear. Overall, during COPD progression, “exhausted” innate immune responses can be observed in the large airways. On the other hand, the innate immune response is enhanced in the small airways. Approaches that inhibit the inflammatory cascade, chemotaxis, or the activation of inflammatory cells could possibly delay the progression of airway remodeling in COPD, and may thus have potential clinical significance.

The respiratory virome and exacerbations in patients with chronic obstructive pulmonary disease

INTRODUCTION

Exacerbations are major contributors to morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD), and respiratory bacterial and viral infections are an important trigger. However, using conventional diagnostic techniques, a causative agent is not always found. Metagenomic next-generation sequencing (mNGS) allows analysis of the complete virome, but has not yet been applied in COPD exacerbations.

OBJECTIVES

To study the respiratory virome in nasopharyngeal samples during COPD exacerbations using mNGS.

STUDY DESIGN

88 nasopharyngeal swabs from 63 patients from the Bergen COPD Exacerbation Study (2006-2010) were analysed by mNGS and in-house qPCR for respiratory viruses. Both DNA and RNA were sequenced simultaneously using an Illumina library preparation protocol with in-house adaptations.

RESULTS

By mNGS, 24/88 samples tested positive. Sensitivity and specificity, as compared with PCR, were 96% and 98% for diagnostic targets (23/24 and 1093/1120, respectively). Additional viral pathogens detected by mNGS were herpes simplex virus type 1 and coronavirus OC43. A positive correlation was found between Cq value and mNGS viral normalized species reads (log value) (p = 0.002). Patients with viral pathogens had lower percentages of bacteriophages (p<0.001). No correlation was found between viral reads and clinical markers.

CONCLUSIONS

The mNGS protocol used was highly sensitive and specific for semi-quantitative detection of respiratory viruses. Excellent negative predictive value implicates the power of mNGS to exclude any pathogenic respiratory viral infectious cause in one test, with consequences for clinical decision making. Reduced abundance of bacteriophages in COPD patients with viral pathogens implicates skewing of the virome during infection, with potential consequences for the bacterial populations, during infection.

Bacterial infections in acute exacerbation of chronic obstructive pulmonary disease: a systematic review and meta-analysis

OBJECTIVE

Due to the importance of Chronic obstructive pulmonary disease (COPD) as the fourth cause of mortality worldwide and the lack of studies evaluating the prevalence of bacterial infections in disease exacerbation, this systematic review and meta-analysis was performed to determine the prevalence rate of bacterial infections in COPD patients.

METHODS

PubMed, ISI Web of Science, and Scopus databases were systematically searched for population-based prevalence studies (1980-2018). MeSH terms for "Bacterial infections" and "AECOPD" were used as search keywords. The selected studies were filtered according to the inclusion and exclusion criteria. Fixed and random-effects models were used for estimation of summary effect sizes. Between-study heterogeneity, as well as publication bias, were calculated.

RESULTS

Finally, 118 out of 31,440 studies were selected. The overall estimation of the prevalence of bacterial infection was 49.59% [95% confidence interval (CI) 0.4418-0.55]. The heterogeneity in estimating the pooled prevalence of bacterial infections was shown in the studies (Cochran Q test: 6615, P < 0.0001, I² = 98.23%). In addition, S. pneumoniae, H. influenzae, M. catarrhalis, A. baumannii, P. aeruginosa, and S. aureus were the most prevalent reported bacteria.

CONCLUSIONS

Our results as the first meta-analysis for the issue demonstrated that bacterial infections are an important risk factor for AECOPD. Further studies must be performed for understanding the exact role of bacterial agents in AECOPD and help physicians for more applicable preventive and therapeutic measurements.

Bacterial load and inflammatory response in sputum of alpha-1 antitrypsin deficiency patients with COPD

Background

Airway inflammation may drive the progression of chronic obstructive pulmonary disease (COPD) associated with alpha-1 antitrypsin deficiency (AATD), but the relationship between airway microbiota and inflammation has not been investigated.

Methods

We studied 21 non-treated AATD (AATD-noT) patients, 20 AATD-COPD patients under augmentation therapy (AATD-AT), 20 cigarette smoke-associated COPD patients, 20 control healthy smokers (CS) and 21 non-smokers (CON) with normal lung function. We quantified sputum inflammatory cells and inflammatory markers (IL-27, CCL3, CCL5, CXCL8, LTB₄, MPO) by ELISA, total bacterial load (16S) and pathogenic bacteria by qRT-PCR.

Results

AATD-AT patients were younger but had similar spirometric and DLCO values compared to cigarette smoke-associated COPD, despite a lower burden of smoking history. Compared to cigarette smoke-associated COPD, AATD-noT and AATD-AT patients had lower sputum neutrophil levels (p=0.0446, p=0.0135), total bacterial load (16S) (p=0.0081, p=0.0223), M. catarrhalis (p=0.0115, p=0.0127) and S. pneumoniae (p=0.0013, p=0.0001). Sputum IL-27 was significantly elevated in CS and cigarette smoke-associated COPD. AATD-AT, but not AATD-noT patients, had IL-27 sputum levels (pg/ml) significantly lower than COPD (p=0.0297) and these positively correlated with FEV₁% predicted values (r=0.578, p=0.0307).

Conclusions

Compared to cigarette smoke-associated COPD, AATD-AT (COPD) patients have a distinct airway inflammatory and microbiological profile. The decreased sputum bacterial load and IL-27 levels in AATD-AT patients suggests that augmentation therapy play a role in these changes.

Chronic obstructive pulmonary disease upper airway microbiota alpha diversity is associated with exacerbation phenotype: a case-control observational study

Background

Chronic obstructive pulmonary disease (COPD) frequent exacerbators (FE) suffer increased morbidity and mortality compared to infrequent exacerbators (IE). The association between the oral and sputum microbiota and exacerbation phenotype is not well defined. The objective of this study was to determine key features that differentiate the oral and sputum microbiota of FEs from the microbiota of IEs during periods of clinical stability.

Methods

We recruited 11 FE and 11 IE who had not used antibiotics or systemic corticosteroids in the last 1 month. Subjects provided oral wash and sputum samples, which underwent 16S V4 MiSeq sequencing and qPCR of 16S rRNA. Data were analyzed using Dada2 and R.

Results

FE and IE were similar in terms of age, FEV₁ percent predicted (FEV1pp), pack-years of tobacco exposure, and St. George’s Respiratory Questionnaire score. 16S copy numbers were significantly greater in sputum vs. oral wash (p = 0.01), but phenotype was not associated with copy number. Shannon diversity was significantly greater in oral samples compared to sputum (p = 0.001), and IE samples were more diverse than FE samples (p < 0.001). Sputum samples from FE had more Haemophilus and Moraxella compared to IE sputum samples, due to dominance of these COPD-associated taxa in three FE sputum samples. Amplicon sequencing variant (ASV)-level analysis of sputum samples revealed one ASV (Actinomyces) was significantly more abundant in IE vs. FE sputum (p_adj = 0.048, Wilcoxon rank-sum test), and this persisted after controlling for FEV1pp. Principal coordinate analysis using Bray-Curtis distance with PERMANOVA analyses demonstrated clustering by anatomic site, phenotype, inhaled corticosteroid use, current tobacco use, COPD severity, and last professional dental cleaning.

Conclusions

FE have less diverse oral and sputum microbiota than IE. Actinomyces was significantly more abundant in IE sputum than FE sputum. The oral and sputum microbiota of COPD subjects cluster based on multiple clinical factors, including exacerbation phenotype. Even during periods of clinical stability, the frequent exacerbator phenotype is associated with decreased alpha diversity, beta-diversity clustering, and changes in taxonomic abundance.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1080-4) contains supplementary material, which is available to authorized users.

Evaluation and Interpretation of Transcriptome Data Underlying Heterogeneous Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease, featured by airflow obstruction. Recently, a comprehensive analysis of the transcriptome in lung tissue of COPD patients was performed, but the heterogeneity of the sample was not seriously considered in characterizing the mechanistic dysregulation of COPD. Here, we established a new transcriptome analysis pipeline using a deconvolution process to reduce the heterogeneity and clearly identified that these transcriptome data originated from the mild or moderate stage of COPD patients. Differentially expressed or co-expressed genes in the protein interaction subnetworks were linked with mitochondrial dysfunction and the immune response, as expected. Computational protein localization prediction revealed that 19 proteins showing changes in subcellular localization were mostly related to mitochondria, suggesting that mislocalization of mitochondria-targeting proteins plays an important role in COPD pathology. Our extensive evaluation of COPD transcriptome data could provide guidelines for analyzing heterogeneous gene expression profiles and classifying potential candidate genes that are responsible for the pathogenesis of COPD.

The Interplay Between Immune Response and Bacterial Infection in COPD: Focus Upon Non-typeable Haemophilus influenzae

Chronic obstructive pulmonary disease (COPD) is a debilitating respiratory disease and one of the leading causes of morbidity and mortality worldwide. It is characterized by persistent respiratory symptoms and airflow limitation due to abnormalities in the lower airway following consistent exposure to noxious particles or gases. Acute exacerbations of COPD (AECOPD) are characterized by increased cough, purulent sputum production, and dyspnea. The AECOPD is mostly associated with infection caused by common cold viruses or bacteria, or co-infections. Chronic and persistent infection by non-typeable Haemophilus influenzae (NTHi), a Gram-negative coccobacillus, contributes to almost half of the infective exacerbations caused by bacteria. This is supported by reports that NTHi is commonly isolated in the sputum from COPD patients during exacerbations. Persistent colonization of NTHi in the lower airway requires a plethora of phenotypic adaptation and virulent mechanisms that are developed over time to cope with changing environmental pressures in the airway such as host immuno-inflammatory response. Chronic inhalation of noxious irritants in COPD causes a changed balance in the lung microbiome, abnormal inflammatory response, and an impaired airway immune system. These conditions significantly provide an opportunistic platform for NTHi colonization and infection resulting in a "vicious circle." Episodes of large inflammation as the consequences of multiple interactions between airway immune cells and NTHi, accumulatively contribute to COPD exacerbations and may result in worsening of the clinical status. In this review, we discuss in detail the interplay and crosstalk between airway immune residents and NTHi, and their effect in AECOPD for better understanding of NTHi pathogenesis in COPD patients.

Lower Airway Virology in Health and Disease-From Invaders to Symbionts

Studies of human airway virome are relatively recent and still very limited. Culture-independent microbial techniques showed growing evidence of numerous viral communities in the respiratory microbial ecosystem. The significance of different acute respiratory viruses is already known in the pathogenesis of chronic conditions, such as asthma, cystic fibrosis (CF), or chronic obstructive lung disease (COPD), and their exacerbations. Viral pathogens, such as influenza, metapneumovirus, parainfluenza, respiratory syncytial virus, or rhinovirus, have been associated with impaired immune response, acute exacerbations, and decrease in lung function in chronic lung diseases. However, more data have attributed a role to Herpes family viruses or the newly identified Anelloviridae family of viruses in chronic diseases, such as asthma, idiopathic pulmonary fibrosis (IPF), or CF. Impaired antiviral immunity, bacterial colonization, or used medication, such as glucocorticoids or antibiotics, contribute to the imbalance of airway microbiome and may shape the local viral ecosystem. A specific part of virome, bacteriophages, frames lung microbial communities through direct contact with its host, the specific bacteria known as Pseudomonas aeruginosa or their biofilm formation. Moreover, antibiotic resistance is induced through phages via horizontal transfer and leads to more severe exacerbations of chronic airway conditions. Morbidity and mortality of asthma, COPD, CF, and IPF remains high, despite an increased understanding and knowledge about the impact of respiratory virome in the pathogenesis of these conditions. Thus, more studies focus on new prophylactic methods or therapeutic agents directed toward viral⁻host interaction, microbial metabolic function, or lung microbial composition rearrangement.

Identification and assessment of COPD exacerbations

Chronic Obstructive Pulmonary Disease (COPD) exacerbations play a central role in the disease natural history of the disease, affecting its overall severity, decreasing pulmonary function, worsening underlying co-morbidities, impairing quality of life (QoL) and leading to severe morbidity and mortality. Therefore, identification and correct assessment of COPD exacerbations is paramount, given it will strongly influence therapy success. For the identification of exacerbations, several questionnaires exist, with varying degrees of complexity. However, most questionnaires remain of limited clinical utility, and symptom scales seem to be more useful in clinical practice. In the assessment of exacerbations, the type and degree of severity should be ascertained in order to define the management setting and optimize treatment options. Still, a consensual and universal classification system to assess the severity and type of an exacerbation is lacking, and there are no established criteria for less severely ill patients not requiring hospital assessment. This might lead to under-reporting of minor to moderate exacerbations, which has an impact on patients' health status. There is a clear unmet need to develop clinically useful questionnaires and a comprehensive system to evaluate the severity of exacerbations that can be used in all settings, from primary health care to general hospitals.

Ceftaroline modulates the innate immune and host defense responses of immunocompetent cells exposed to cigarette smoke

BACKGROUND

Cigarette smoke, the principal risk factor for chronic obstructive pulmonary disease (COPD), negatively influences the effectiveness of the immune system's response to a pathogen. The antibiotic ceftaroline exerts immune-modulatory effects in bronchial epithelial cells exposed to cigarette smoke.

AIMS AND METHODS

The present study aims to assess the effects of ceftaroline on TLR2 and TLR4 expression, LPS binding and TNF-α and human beta defensin (HBD2) release in an undifferentiated and PMA-differentiated human monocyte cell line (THP-1) exposed or not to cigarette smoke extracts (CSE). TLR2, TLR4, and LPS binding were assessed by flow cytometry, TNF-α and HBD2 release were evaluated by ELISA.

RESULTS

The constitutive expression of TLR2 and TLR4 and LPS binding were higher in differentiated compared to undifferentiated THP-1 cells. In undifferentiated THP-1 cells, CSE increased TLR2 and TLR4 protein levels, LPS binding and TNF-α release and reduced HBD2 release and ceftaroline counteracted all these effects. In differentiated THP-1, CSE did not significantly affect TLR2 and TLR4 expression and LPS binding but reduced HBD2 release and increased TNF-α release. Ceftaroline counteracted the effects of CSE on HBD2 release in differentiated THP-1.

CONCLUSION

Ceftaroline counteracts the effect of CSE in immune cells by increasing the effectiveness of the innate immune system. This effect may also assist in reducing pathogen activity and recurrent exacerbations in COPD patients.

Th17 profile in COPD exacerbations

COPD is characterized by an ongoing inflammatory process of the airways that leads to obstruction or limitation of airflow. It is mainly associated with exposure to cigarette smoke. In addition, it is considered, at present, a serious public health problem, ranking fourth in mortality worldwide. Many cells participate in the pathophysiology of COPD, the most important are neutrophils, macrophages and CD4+ and CD8+ T cells. Neutrophil migration to the inflammation area could be mediated largely by cytokines related to CD4+ Th17 lymphocytes, because it has been shown that IL-17A, IL-17F and IL-22 act as inducers for CXCL8, CXCL1, CXCL5, G-CSF, and GM-CSF secretion by epithelial cells of the airways. The aims of these molecules are differentiation, proliferation and recruitment of neutrophils. Furthermore, it is believed that CD4+ lymphocytes Th17 may be involved in protection against pathogens for which Th1 and Th2 are not prepared to fight. In COPD exacerbations, there is an increased cellularity in the lung region and respiratory tract. Therefore, the increase in the number of neutrophils and macrophages in the airways and the increase in proinflammatory cytokines are directly related to the severity of exacerbations and that is the importance of the functions of Th17 profile in this entity.

Bronchial inflammation and bacterial load in stable COPD is associated with TLR4 overexpression

Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain (NOD)-like receptors (NLRs) are two major forms of innate immune sensors but their role in the immunopathology of stable chronic obstructive pulmonary disease (COPD) is incompletely studied. Our objective here was to investigate TLR and NLR signalling pathways in the bronchial mucosa in stable COPD.

Using immunohistochemistry, the expression levels of TLR2, TLR4, TLR9, NOD1, NOD2, CD14, myeloid differentiation primary response gene 88 (MyD88), Toll-interleukin-1 receptor domain-containing adaptor protein (TIRAP), and the interleukin-1 receptor-associated kinases phospho-IRAK1 and IRAK4 were measured in the bronchial mucosa of subjects with stable COPD of different severity (n=34), control smokers (n=12) and nonsmokers (n=12). The bronchial bacterial load of Pseudomonas aeruginosa, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae was measured by quantitative real-time PCR.

TLR4 and NOD1 expression was increased in the bronchial mucosa of patients with severe/very severe stable COPD compared with control subjects. TLR4 bronchial epithelial expression correlated positively with CD4+ and CD8+ cells and airflow obstruction. NOD1 expression correlated with CD8+ cells. The bronchial load of P. aeruginosa was directly correlated, but H. influenzae inversely correlated, with the degree of airflow obstruction. Bacterial load did not correlate with inflammatory cells.

Bronchial epithelial overexpression of TLR4 and NOD1 in severe/very severe stable COPD, associated with increased bronchial inflammation and P. aeruginosa bacterial load, may play a role in the pathogenesis of COPD.

Neutrophil targeted nano-drug delivery system for chronic obstructive lung diseases

The success of drug delivery to target airway cell(s) remains a significant challenge due to the limited ability of nanoparticle (NP) systems to circumvent protective airway-defense mechanisms. The size, density, surface and physical-chemical properties of nanoparticles are the key features that determine their ability to navigate across the airway-barrier. We evaluated here the efficacy of a PEGylated immuno-conjugated PLGA-nanoparticle (PINP) to overcome this challenge and selectively deliver drug to specific inflammatory cells (neutrophils). We first characterized the size, shape, surface-properties and neutrophil targeting using dynamic laser scattering, transmission electron microscopy and flow cytometry. Next, we assessed the efficacy of neutrophil-targeted PINPs in transporting through the airway followed by specific binding and release of drug to neutrophils. Finally, our results demonstrate the efficacy of PINP mediated non-steroidal anti-inflammatory drug-(ibuprofen) delivery to neutrophils in murine models of obstructive lung diseases, based on its ability to control neutrophilic-inflammation and resulting lung disease.