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

Neutrophil Extracellular Traps and Respiratory Disease

Extracellular traps made by neutrophils (NETs) and other leukocytes such as macrophages and eosinophils have a key role in the initial immune response to infection but are highly inflammatory and may contribute to tissue damage. They are particularly relevant to lung disease, with the pulmonary anatomy facilitating their ability to fully extend into the airways/alveolar space. There has been a rapid expansion in the number of published studies demonstrating their role in a variety of important respiratory diseases including chronic obstructive pulmonary disease, cystic fibrosis, bronchiectasis, asthma, pneumonia, COVID-19, rhinosinusitis, interstitial lung disease and lung cancer. The expression of NETs and other traps is a specific process, and diagnostic tests need to differentiate them from other inflammatory pathways/causes of cell death that are also characterised by the presence of extracellular DNA. The specific targeting of this pathway by relevant therapeutics may have significant clinical benefit; however, current clinical trials/evidence are at a very early stage. This review will provide a broad overview of the role of NETs and their possible treatment in respiratory disease.

Predicting the risk of pulmonary infection in patients with chronic kidney failure: A-C2GH2S risk score-a retrospective study

PURPOSE

The objective of this study is to investigate the associated risk factors of pulmonary infection in individuals diagnosed with chronic kidney disease (CKD). The primary goal is to develop a predictive model that can anticipate the likelihood of pulmonary infection during hospitalization among CKD patients.

METHODS

This retrospective cohort study was conducted at two prominent tertiary teaching hospitals. Three distinct models were formulated employing three different approaches: (1) the statistics-driven model, (2) the clinical knowledge-driven model, and (3) the decision tree model. The simplest and most efficient model was obtained by comparing their predictive power, stability, and practicability.

RESULTS

This study involved a total of 971 patients, with 388 individuals comprising the modeling group and 583 individuals comprising the validation group. Three different models, namely Models A, B, and C, were utilized, resulting in the identification of seven, four, and eleven predictors, respectively. Ultimately, a statistical knowledge-driven model was selected, which exhibited a C-statistic of 0.891 (0.855-0.927) and a Brier score of 0.012. Furthermore, the Hosmer-Lemeshow test indicated that the model demonstrated good calibration. Additionally, Model A displayed a satisfactory C-statistic of 0.883 (0.856-0.911) during external validation. The statistical-driven model, known as the A-C2GH2S risk score (which incorporates factors such as albumin, C2 [previous COPD history, blood calcium], random venous blood glucose, H2 [hemoglobin, high-density lipoprotein], and smoking), was utilized to determine the risk score for the incidence rate of lung infection in patients with CKD. The findings revealed a gradual increase in the occurrence of pulmonary infections, ranging from 1.84% for individuals with an A-C2GH2S Risk Score ≤ 6, to 93.96% for those with an A-C2GH2S Risk Score ≥ 18.5.

CONCLUSION

A predictive model comprising seven predictors was developed to forecast pulmonary infection in patients with CKD. This model is characterized by its simplicity, practicality, and it also has good specificity and sensitivity after verification.

Therapeutic targets and potential delivery systems of melatonin in osteoarthritis

Osteoarthritis (OA) is a highly prevalent age-related musculoskeletal disorder that typically results in chronic pain and disability. OA is a multifactorial disease, with increased oxidative stress, dysregulated inflammatory response, and impaired matrix metabolism contributing to its onset and progression. The neurohormone melatonin, primarily synthesized by the pineal gland, has emerged as a promising therapeutic agent for OA due to its potential to alleviate inflammation, oxidative stress, and chondrocyte death with minimal adverse effects. The present review provides a comprehensive summary of the current understanding regarding melatonin as a promising pharmaceutical agent for the treatment of OA, along with an exploration of various delivery systems that can be utilized for melatonin administration. These findings may provide novel therapeutic strategies and targets for inhibiting the advancement of OA.

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).

Pulmonary delivery systems for antimicrobial peptides

Bacterial infections of the respiratory tract cause millions of deaths annually. Several diseases exist wherein (1) bacterial infection is the main cause of disease (e.g., tuberculosis and bacterial pneumonia), (2) bacterial infection is a consequence of disease and worsens the disease prognosis (e.g., cystic fibrosis), and (3) bacteria-triggered inflammation propagates the disease (e.g., chronic obstructive pulmonary disease). Current approaches to combat infections generally include long and aggressive antibiotic treatments, which challenge patient compliance, thereby making relapses common and contributing to the development of antibiotic resistance. Consequently, the proportion of infections that cannot be treated with conventional antibiotics is rapidly increasing, and novel therapies are urgently needed. In this context, antimicrobial peptides (AMPs) have received considerable attention as they may exhibit potent antimicrobial effects against antibiotic-resistant bacterial strains but with modest toxicity. In addition, some AMPs suppress inflammation and provide other host defense functions (motivating the alternative term host defense peptides (HDPs)). However, the delivery of AMPs is complicated because they are large, positively charged, and amphiphilic. As a result of this, AMP delivery systems have recently attracted attention. For airway infections, the currently investigated delivery approaches range from aerosols and dry powders to various self-assembly and nanoparticle carrier systems, as well as their combinations. In this paper, we discuss recent developments in the field, ranging from mechanistic mode-of-action studies to the application of these systems for combating bacterial infections in the airways.

Lung and Heart Biology of the Dp16 Mouse Model of down Syndrome: Implications for Studying Cardiopulmonary Disease

(1) Background: We sought to investigate the baseline lung and heart biology of the Dp16 mouse model of Down syndrome (DS) as a prelude to the investigation of recurrent respiratory tract infection. (2) Methods: In controls vs. Dp16 mice, we compared peripheral blood cell and plasma analytes. We examined baseline gene expression in lungs and hearts for key parameters related to susceptibility of lung infection. We investigated lung and heart protein expression and performed lung morphometry. Finally, and for the first time each in a model of DS, we performed pulmonary function testing and a hemodynamic assessment of cardiac function. (3) Results: Dp16 mice circulate unique blood plasma cytokines and chemokines. Dp16 mouse lungs over-express the mRNA of triplicated genes, but not necessarily corresponding proteins. We found a sex-specific decrease in the protein expression of interferon α receptors, yet an increased signal transducer and activator of transcription (STAT)-3 and phospho-STAT3. Platelet-activating factor receptor protein was not elevated in Dp16 mice. The lungs of Dp16 mice showed increased stiffness and mean linear intercept and contained bronchus-associated lymphoid tissue. The heart ventricles of Dp16 mice displayed hypotonicity. Finally, Dp16 mice required more ketamine to achieve an anesthetized state. (4) Conclusions: The Dp16 mouse model of DS displays key aspects of lung heart biology akin to people with DS. As such, it has the potential to be an extremely valuable model of recurrent severe respiratory tract infection in DS.

Re-exacerbation within 30 days of discharge is associated with poor prognosis in the following year among patients hospitalised with exacerbation of chronic obstructive pulmonary disease: a clinical cohort study

BACKGROUND

Exacerbation of chronic obstructive pulmonary disease (ECOPD) is a complex phenomenon, with marked heterogeneity in the aetiology, pathophysiology and clinical manifestations. This study aimed to evaluate the clinical characteristics and long-term outcomes of patients with 30-day exacerbation among those hospitalised with ECOPD in China.

METHODS

Data from the Acute Exacerbations of Chronic Obstructive Pulmonary Disease Inpatient Registry were used in this study. The patients were divided into re-event and non-event groups based on the incidence of re-exacerbation within 30 days of discharge. Exacerbation, severe exacerbation and all-cause readmissions in the following 12 months were the outcomes of interest. The cumulative incidence rates and incidence densities were calculated. Multivariate hazard function models were used to determine the association between 30-day re-exacerbation and the long-term outcomes after accounting for the competing risk of death.

RESULTS

Re-exacerbation within 30 days of discharge was observed in 4.9% (n=242) of the patients (n=4963). The cumulative incidence rates and incidence densities of exacerbation, severe exacerbation and all-cause readmissions in the event group were significantly higher than those in the non-event group. After adjustment, re-exacerbation within 30 days of discharge was associated with increased risks of exacerbation, severe exacerbation and all-cause readmissions in the following 12 months (adjusted HR: 3.85 (95% CI: 3.09 to 4.80), 3.46 (2.66 to 4.50) and 3.28 (2.52 to 4.25) accordingly).

CONCLUSION

Re-exacerbation of COPD within 30 days of discharge is a significant predictor of long-term prognosis. In clinical practice, short-term re-exacerbation is a significant clinical phenotype of ECOPD that requires careful management at the earliest.

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.

Using system biology and bioinformatics to identify the influences of COVID-19 co-infection with influenza virus on COPD

Coronavirus disease 2019 (COVID-19) has speedily increased mortality globally. Although they are risk factors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), less is known about the common molecular mechanisms behind COVID-19, influenza virus A (IAV), and chronic obstructive pulmonary disease (COPD). This research used bioinformatics and systems biology to find possible medications for treating COVID-19, IAV, and COPD via identifying differentially expressed genes (DEGs) from gene expression datasets (GSE171110, GSE76925, GSE106986, and GSE185576). A total of 78 DEGs were subjected to functional enrichment, pathway analysis, protein-protein interaction (PPI) network construct, hub gene extraction, and other potentially relevant disorders. Then, DEGs were discovered in networks including transcription factor (TF)-gene connections, protein-drug interactions, and DEG-microRNA (miRNA) coregulatory networks by using NetworkAnalyst. The top 12 hub genes were MPO, MMP9, CD8A, HP, ELANE, CD5, CR2, PLA2G7, PIK3R1, SLAMF1, PEX3, and TNFRSF17. We found that 44 TFs-genes, as well as 118 miRNAs, are directly linked to hub genes. Additionally, we searched the Drug Signatures Database (DSigDB) and identified 10 drugs that could potentially treat COVID-19, IAV, and COPD. Therefore, we evaluated the top 12 hub genes that could be promising DEGs for targeted therapy for SARS-CoV-2 and identified several prospective medications that may benefit COPD patients with COVID-19 and IAV co-infection.

[Clinic and functional features of chronic obstructive pulmonary disease after virus-induced acute exacerbations.]

AIM

To establish symptoms, lung function and to evaluate subsequent exacerbations of chronic obstructive pulmonary disease (COPD) during a year after virus-induced COPD exacerbations.

MATERIALS AND METHODS

Patients hospitalized with viral (n=60), bacterial (n=60) and viral-bacterial (n=60) COPD exacerbations were enrolled to single-center prospective observational study. COPD was diagnosed according spirography criteria. Viral infection was established in bronchoalveolar lavage fluid or sputum by real-time reverse transcription-polymerase chain reaction for RNA of influenza A and B virus, rhinovirus, respiratory syncytial virus and SARS-CoV-2. Symptoms, lung function, COPD exacerbations were assessed. Patients were investigated at the hospitalization onset and then 4 and 52 weeks following the discharge from the hospital.

RESULTS

After 52 weeks in viral and viral-bacterial COPD exacerbations groups the rate of forced expiratory volume in one second (FEV1) decline were maximal - 71 (68; 73) ml/year and 69 (67; 72) ml/year versus 59 (55; 62) ml/year after bacterial exacerbations. Low levels of diffusion lung capacity for carbon monoxide (DLco/Va) - 52.5% (45.1%; 55.8%), 50.2% (44.9%; 56.0%) and 75.3% (72.2%; 80.1%) respectively, of 6-minute walk distance; p<0.001 in relation to bacterial exacerbations. In Cox proportional hazards regression analyses viral and viral-bacterial exacerbations were associated with increased risk of subsequent COPD exacerbations by 2.4 times independent of exacerbations rate before index event and FEV1. In linear regression models the relationships between airflow limitation and respiratory syncytial virus, rhinovirus and influenza virus infection, between low DLco/Va and rhinovirus, influenza virus and SARS-CoV-2 infection.

CONCLUSION

COPD after virus-induced exacerbations were characterized by progression of airflow limitation, low DLco/Va, low 6-minute walking test distance, subsequent COPD exacerbations risk.

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.

Clinical significance of serum levels of 14-3-3β protein in patients with stable chronic obstructive pulmonary disease

Nowadays, the diagnosis and treatment of COPD are often based on the results of lung function tests. Certain individuals, however, are not candidates for lung function testing due to pulmonary bullae, cardiac failure, low lung function, and other factors. Therefore, we evaluated whether serum tyrosine3-monooxygenase/tryptophan5-monooxygenase activation protein β (14-3-3β) could be a biomarker for the diagnosis of stable COPD patients. The expression of serum 14-3-3β protein was evaluated by an enzyme-linked immunosorbent assay. The association between its concentrations and clinical parameters of stable COPD patients were analyzed by correlation analysis and ROC curve. The results before propensity score matching (PSM) showed that serum 14-3-3β protein concentrations (ng/ml) in stable COPD patients were significantly higher than in healthy controls (P < 0.001). Furthermore, serum 14-3-3β protein concentrations were higher in GOLD 3&4 COPD patients compared with healthy participants, GOLD 1 and GOLD 2 COPD patients (P < 0.05), which shows that the concentration of 14-3-3β protein correlates with disease severity in stable COPD patients. After 1:1 PSM, there was also a statistically significant rise in 14-3-3 protein levels in stable COPD patients compared to healthy controls (P < 0.01). Serum 14-3-3β protein levels were positively correlated with blood neutrophil levels (P < 0.05), and negatively related to lung function parameters in stable COPD patients (P < 0.01). When the cutoff value was set at 29.53 ng/ml, the ROC curve yielded a sensitivity of 84.9% and a specificity of 68.3% for diagnosing stable COPD. The 14-3-3β protein may be a potential serum biomarker for the diagnosis of stable COPD patients, which is associated with disease severity, systemic inflammation, and small airway obstruction.

Tanshinone increases Hemopexin expression in lung cells and macrophages to protect against cigarette smoke-induced COPD and enhance antiviral responses

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease, while respiratory infections can elicit exacerbations in COPD patients to mediate increased mortality. Administration of Tanshinones (TS) derivatives has been demonstrated to protect against cigarette smoking (CS) and lipopolysaccharide (LPS)-induced COPD progression. However, the underlying molecular mechanisms and the roles of TS in mitigating the severity of viral-mediated exacerbations of COPD have not been elucidated. Here, we found that TS treatments significantly attenuated lung function decline, inflammatory responses and oxidative stress in CS and LPS-induced COPD mice. Subsequent RNA-seq analysis revealed significantly upregulated Hemopexin expression and enriched interferons (IFNs) signaling pathways in lung tissues of COPD mice upon TS treatments. Moreover, TS administration demonstrated Hemopexin-dependent beneficial roles in BEAS-2B lung cells and RAW264.7 macrophages, which was associated with the suppression of oxidative stress and ERK, NF-κB, and NLRP3 inflammasome signaling pathways-mediated inflammation. Furthermore, TS promoted IFN signaling and rescued impaired antiviral responses in CS and LPS-exposed lung cells that were infected by influenza virus. Notably, hemopexin over-expression in lung cells and macrophages recapitulated the pharmacological activities of TS. Taken together, these results indicate that TS administration is a promising and potential therapeutic strategy for treating COPD and preventing COPD exacerbations.

Pyroptosis and degenerative diseases of the elderly

Pyroptosis is a recently described mechanism of programmed cell death mediated by proteins of the gasdermin family. Widely recognized signaling cascades include the classical, non-classical, caspase-3-dependent gasdermin E and caspase-8-dependent gasdermin D pathways. Additional pyroptotic pathways have been subsequently reported. With the rising prevalence of advanced age, the role of pyroptosis in the degenerative diseases of the elderly has attracted increased research attention. This article reviews the primary mechanisms of pyroptosis and summarizes progress in the research of degenerative diseases of the elderly such as presbycusis, age-related macular degeneration, Alzheimer's disease, intervertebral disc degeneration, and osteoarthritis.

Astaxanthin Prevents Tuberculosis-Associated Inflammatory Injury by Inhibiting the Caspase 4/11-Gasdermin-Pyroptosis Pathway

Pyroptosis is a programmed cell death caused by inflammation. Multiple studies have suggested that Mycobacterium tuberculosis infection causes tissue pyroptosis. However, there are currently no protective drugs against the inflammatory damage caused by pyroptosis. In this study, anti-pyroptotic effects of the natural compound astaxanthin (ASTA) were explored in a simulated pulmonary tuberculosis-associated inflammatory environment. The results showed that ASTA maintained the stability of MLE-12 lung epithelial cell numbers in the inflammatory environment established by lipopolysaccharide. The reason is not to promote cell proliferation but to inhibit lipopolysaccharide-induced pyroptosis. The results showed that ASTA significantly inhibited the expression of key proteins in the caspase 4/11-gasdermin D pathway and the release of pyroptosis-related inflammatory mediators. Therefore, ASTA inhibits inflammation-induced pyroptosis by inhibiting the caspase 4/11-gasdermin D pathway and has the potential to protect lung tissue from tuberculosis-related inflammatory injury. ASTA, a functional food component, is a promising candidate for protection against tuberculosis-associated inflammatory lung injury.

The role of lung macrophages in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) as a common, preventable and treatable chronic respiratory disease in clinic, gets continuous deterioration and we can't take effective intervention at present. Lung macrophages (LMs) are closely related to the occurrence and development of COPD, but the specific mechanism is not completely clear. In this review we will focus on the role of LMs and potential avenues for therapeutic targeting for LMs in COPD.

Screening and identification of tissue-infiltrating immune cells and genes for patients with emphysema phenotype of COPD

Objective

To study the tissue-infiltrating immune cells of the emphysema phenotype of chronic obstructive pulmonary disease (COPD) and find the molecular mechanism related to the development of emphysema to offer potential targets for more precise treatment of patients with COPD.

Methods

Combined analyses of COPD emphysema phenotype lung tissue-related datasets, GSE47460 and GSE1122, were performed. CIBERSORT was used to assess the distribution of tissue-infiltrating immune cells. Weighted gene co-expression network analysis (WGCNA) was used to select immune key genes closely related to clinical features. Rt-qPCR experiments were used for the validation of key genes. Emphysema risk prediction models were constructed by logistic regression analysis and a nomogram was developed.

Results

In this study, three immune cells significantly associated with clinical features of emphysema (FEV1 post-bronchodilator % predicted, GOLD Stage, and DLCO) were found. The proportion of neutrophils (p=0.025) infiltrating in the emphysema phenotype was significantly increased compared with the non-emphysema phenotype, while the proportions of M2 macrophages (p=0.004) and resting mast cells (p=0.01) were significantly decreased. Five immune-related differentially expressed genes (DEGs) were found. WGCNA and clinical lung tissue validation of patients with emphysema phenotype were performed to further screen immune-related genes closely related to clinical features. A key gene (SERPINA3) was selected and included in the emphysema risk prediction model. Compared with the traditional clinical prediction model (AUC=0.923), the combined prediction model, including SERPINA3 and resting mast cells (AUC=0.941), had better discrimination power and higher net benefit.

Conclusion

This study comprehensively analyzed the tissue-infiltrating immune cells significantly associated with emphysema phenotype, including M2 macrophages, neutrophils, and resting mast cells, and identified SERPINA3 as a key immune-related gene.

Pulmonary Delivery of Emerging Antibacterials for Bacterial Lung Infections Treatment

Bacterial infections in the respiratory tract are considered as one of the major challenges to the public health worldwide. Pulmonary delivery is an attractive approach in the management of bacterial respiratory infections with a few inhaled antibiotics approved. However, with the rapid emergence of antibiotic-resistant bacteria, it is necessary to develop new/alternative inhaled antibacterial agents in the post-antibiotic era. A pipeline of novel biological antibacterial agents, including antimicrobial peptides, RNAi therapeutics, and bacteriophages, has emerged to combat bacterial infections with excellent performance. In this review, the causal effects of bacterial infections on the related pulmonary infectious diseases will be firstly introduced. This is followed by an overview on the development of emerging antibacterial therapeutics for managing lung bacterial infections through nebulization/inhalation of dried powders. The obstacles and underlying proposals regarding their clinical transformation are also discussed to seek insights for further development. Research on inhaled therapy of these emerging antibacterials are still in the infancy, but the promising progress warrants further attention.

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

Exploring the Change of Host and Microorganism in Chronic Obstructive Pulmonary Disease Patients Based on Metagenomic and Metatranscriptomic Sequencing

Background

Chronic obstructive pulmonary disease (COPD) is a universal respiratory disease resulting from the complex interactions between genes and environmental conditions. The process of COPD is deteriorated by repeated episodes of exacerbations, which are the primary reason for COPD-related morbidity and mortality. Bacterial pathogens are commonly identified in patients’ respiratory tracts both in the stable state and during acute exacerbations, with significant changes in the prevalence of airway bacteria occurring during acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Therefore, the changes in microbial composition and host inflammatory responses will be necessary to investigate the mechanistic link between the airway microbiome and chronic pulmonary inflammation in COPD patients.

Methods

We performed metatranscriptomic and metagenomic sequencing on sputum samples for twelve AECOPD patients before treatment and for four of them stable COPD (stabilization of AECOPD patients after treatment). Sequencing reads were classified by Kraken2, and the host gene expression was analyzed by Hisat2 and HTseq. The correlation between genes was obtained by the Spearman correlation coefficient. Mann–Whitney U-test was applied to identify microbes that exhibit significantly different distribution in two groups.

Results

At the phyla level, the top 5 dominant phyla were Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, and Fusobacteria. The proportion of dominant gates in metagenomic data was similar in metatranscriptomic data. There were significant differences in the abundance of specific microorganisms at the class level between the two methods. No significant difference between AECOPD and stable COPD was found. However, the different expression levels of 5 host genes were significantly increased in stable COPD and were involved in immune response and inflammatory pathways, which were associated with macrophages.

Conclusion

Our study may provide a clue to investigate the mechanism of COPD and potential biomarkers in clinical diagnosis and treatment.

Moraxella catarrhalis evades neutrophil oxidative stress responses providing a safer niche for nontypeable Haemophilus influenzae

Moraxella catarrhalis and nontypeable Haemophilus influenzae (NTHi) are pathogenic bacteria frequently associated with exacerbation of chronic obstructive pulmonary disease (COPD), whose hallmark is inflammatory oxidative stress. Neutrophils produce reactive oxygen species (ROS) which can boost antimicrobial response by promoting neutrophil extracellular traps (NET) and autophagy. Here, we showed that M. catarrhalis induces less ROS and NET production in differentiated HL-60 cells compared to NTHi. It is also able to actively interfere with these responses in chemically activated cells in a phagocytosis and opsonin-independent and contact-dependent manner, possibly by engaging host immunosuppressive receptors. M. catarrhalis subverts the autophagic pathway of the phagocytic cells and survives intracellularly. It also promotes the survival of NTHi which is otherwise susceptible to the host antimicrobial arsenal. In-depth understanding of the immune evasion strategies exploited by these two human pathogens could suggest medical interventions to tackle COPD and potentially other diseases in which they co-exist.

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Mcat induces ROS and NET production to a lesser extent than NTHi in dHL-60 cells

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Mcat interferes with ROS-related responses in chemically-activated cells

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Mcat subverts the autophagic pathway surviving intracellularly while NTHi does not

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Intracellular survival of NTHi is enhanced by the co-infecting bacterium Mcat

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.

Eosinopenia as a biomarker for antibiotic use in COPD exacerbations: protocol for a retrospective hospital-based cohort study

INTRODUCTION

The acute exacerbation of chronic obstructive pulmonary disease (AECOPD) has a seriously negative impact on patients' healths condition and disease progression. Bacterial infection is closely related to AECOPD, and antibiotics are frequently used in clinical practice. The lack of specific biomarkers for rational antibiotics use always leads to antibiotics abuse in chronic obstructive pulmonary disease (COPD) flare-ups. Eosinopenia has been considered to be related to increased bacterial load of potentially pathogenic organisms at the onset of COPD exacerbations. Therefore, this study aims to investigate whether eosinopenia could be used as a reference for the use of antibiotics in AECOPD.

METHODS AND ANALYSIS

In this study, a hospital-based retrospective cohort design will be adopted to analyse the clinical data of inpatients who are primarily diagnosed with AECOPD in West China Hospital of Sichuan University from 1 January 2010 to 31 December 2020. Relevant data will be extracted from the Clinical Big Data Platform for Scientific Research in West China Hospital, including demographic characteristics, blood eosinophil count, procalcitonin, C reactive protein, microbial cultivation, antibiotics use, length of hospital stay, non-invasive ventilation use, intensive care unit transfer and mortality, etc. The collected data will be described and inferred by corresponding statistical methods according to the data type and their distributions. Multiple binary logistic regression models will be used to analyse the relationship between blood eosinophil count and bacterial infection. The antibiotics use, and patient morbidity and mortality will be compared between patients with or without eosinopenia.

ETHICS AND DISSEMINATION

This study has been approved by the Biomedical Ethics Review Board of West China Hospital of Sichuan University (Approval No. 2020-1056). And the research results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR2000039379.

Virome in the Lungs: The Role of Anelloviruses in Childhood Respiratory Diseases

More recently, increasing attention has been directed to exploring the function of the global virome in health and disease. Currently, by new molecular techniques, such as metagenomic DNA sequencing, the virome has been better unveiled. By investigating the human lung virome, we could provide novel insights into respiratory diseases. The virome, as a part of the microbiome, is characterized by a constant change in composition related to the type of diet, environment, and our genetic code, and other incalculable factors. The virome plays a substantial role in modulating human immune defenses and contributing to the inflammatory processes. Anelloviruses (AVs) are new components of the virome. AVs are already present during early life and reproduce without apparently causing harm to the host. The role of AVs is still unknown, but several reports have shown that AVs could activate the inflammasomes, intracellular multiprotein oligomers of the innate immune system, which show a crucial role in the host defense to several pathogens. In this narrative revision, we summarize the epidemiological data related to the possible link between microbial alterations and chronic respiratory diseases in children. Briefly, we also describe the characteristics of the most frequent viral family present in the lung virome, Anelloviridae. Furthermore, we discuss how AVs could modulate the immune system in children, affecting the development of chronic respiratory diseases, particularly asthma, the most common chronic inflammatory disease in childhood.

Chronic Obstructive Pulmonary Disease Treatment and Pharmacist-Led Medication Management

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death across the globe. Its repeated exacerbation will seriously worsen the quality of life, aggravate the patients’ symptoms, and bring a heavy burden on the patients and the society. Understanding the current status of drug therapy and the role of pharmaceutical care is essential for the management of COPD. In addition to the drugs already on the market, recent clinical trials also show that emerging novel drugs for treating COPD are being developed to prevent the symptoms, reduce the frequency of acute exacerbation, and improve the quality of life. Recent progress in new drug research should lead to novel treatment options for COPD patients in future clinical practice. The pharmaceutical care has shown significantly favourable impacts on addressing drug-related problems, supporting its vital role in the management of COPD, especially when there are a wide range of therapeutic agents. This review not only provides an overview of current treatment strategies but also further underlines the importance of new drug development and pharmaceutical care for patients with COPD.