Treating Neutrophilic Inflammation in Airways Diseases

Reliability of blood eosinophil count in steady-state bronchiectasis

RATIONALE

The baseline value of eosinophils in peripheral blood (BEC) has been associated with different degrees of severity, prognosis and response to treatment in patients with bronchiectasis. It is not known, however, if this basal value remains constant over time.

OBJECTIVES

The aim of this study was to assess whether the BEC remains stable in the long term in patients with bronchiectasis.

METHODS AND MEASUREMENTS

Patients from the RIBRON registry of bronchiectasis diagnosed by computed tomography with at least 2 BEC measurements one year apart were included in the study. Patients with asthma and those taking anti-eosinophilic drugs were excluded. Reliability was assessed using the intra-class correlation coefficient (ICC). A patient with a BEC of at least 300 cells/uL or less than 100 cells/uL was considered eosinophilic or eosinopenic, respectively. Group changes over time were also calculated.

MAIN RESULTS

Seven hundred and thirteen patients were finally included, with a mean age of 66.5 (13.2) years (65.8 % women). A total of 2701 BEC measurements were performed, with a median number of measurements per patient of 4 (IQR: 2-5) separated by a median of 12.1 (IQR: 10.5-14.3) months between two consecutive measurements. The ICC was good (>0.75) when calculated between two consecutive measurements (approximately one year apart) but had dropped significantly by the time of the next annual measurements. Similarly, the change from an eosinophilic or eosinopenic patient to a non-eosinophilic or non-eosinopenic patient, respectively, was less than 30 % during the first year with respect to the baseline value but was close to 50 % in later measurements.

CONCLUSIONS

Given the significant changes observed in the baseline value of the BEC over time, its monitoring is necessary in patients with bronchiectasis in order to more reliably assess its usefulness.

The perfect storm: when COPD meets bronchiectasis

COPD can coexist with bronchiectasis (BE). These patients have different clinical profiles compared to those with BE with fixed airflow limitation. https://bit.ly/3Z9qNOb.

Molecular Approaches to Treating Chronic Obstructive Pulmonary Disease: Current Perspectives and Future Directions

Chronic obstructive pulmonary disease (COPD) is a clinical syndrome that presents as airflow limitation with poor reversibility accompanied by dynamic hyperinflation of the lung. It is a complex disease with chronic inflammatory airway changes caused by exposure to noxious particles or gases, such as cigarette smoke. The disease involves persistent inflammation and oxidative stress, perpetuated by frequent exacerbations. The prevalence of COPD is on the rise, with the prediction that it will be the leading cause of morbidity and mortality over the next decade. Despite the global burden of COPD and its associated morbidity and mortality, treatment remains limited. Although the understanding of the pathogenesis of COPD has increased over the last two decades, molecular approaches to develop new therapies for the treatment of COPD have lagged. Here, we review the molecular approaches that have the potential for developing novel therapies for COPD.

Persistent Blood Eosinophilia and Eosinopenia: Relationship with Outcomes in Bronchiectasis

INTRODUCTION

Blood eosinophil counts (BEC) have been related to the severity of bronchiectasis and its response to inhaled corticosteroids. However, only the baseline BEC has been used to assess this relationship and it is known that BEC could change over time. The objective of this study is to analyse the association of persistent eosinophilia or eosinopenia with outcomes in bronchiectasis.

METHODS

Multicentre, prospective and observational study from 43 centres in Spain derived from the Spanish Bronchiectasis Registry (RIBRON). Asthma and anti-eosinophil treatments were excluded. Patients with at least two yearly BEC measures (including the baseline measure) were included. Persistent eosinophilia (at least 300cells/μL) or persistent eosinopenia (less than 100cells/μL) were defined as the persistence in the same eosinophil group after three yearly measures (being the baseline the first measure).

RESULTS

Five hundred two patients with at least three BEC measures were included; 24.5% and 16.6% presented baseline eosinophilia or eosinopenia, respectively. Of these, 57.7% and 56.6% presented persistent eosinophilia and eosinopenia, respectively. Patients with persistent eosinophilia presented greater severity and a higher number/greater severity of exacerbations than those with non-persistent eosinophilia and those with persistent or non-persistent eosinopenia. Finally, patients with non-persistent eosinopenia presented more severity and a higher number/greater severity of exacerbations than those with non-persistent eosinophilia.

CONCLUSION

When only the baseline BEC was taken into account, patients with eosinopenia presented greater severity than those with eosinophilia. However, patients with persistent eosinophilia presented greater severity than those with persistent eosinopenia. Monitoring the BEC seems to be important in bronchiectasis.

Analysis of factors influencing bronchiectasis patients with active pulmonary tuberculosis and development of a nomogram prediction model

Background

To identify the risk factors for bronchiectasis patients with active pulmonary tuberculosis (APTB) and to develop a predictive nomogram model for estimating the risk of APTB in bronchiectasis patients.

Methods

A retrospective cohort study was conducted on 16,750 bronchiectasis patients hospitalized at the Affiliated Hospital of Guangdong Medical University and the Second Affiliated Hospital of Guangdong Medical University between January 2019 and December 2023. The 390 patients with APTB were classified as the case group, while 818 patients were randomly sampled by computer at a 1:20 ratio from the 16,360 patients with other infections to serve as the control group. Relevant indicators potentially leading to APTB in bronchiectasis patients were collected. Patients were categorized into APTB and inactive pulmonary tuberculosis (IPTB) groups based on the presence of tuberculosis. The general characteristics of both groups were compared. Variables were screened using the least absolute shrinkage and selection operator (LASSO) analysis, followed by multivariate logistic regression analysis. A nomogram model was established based on the analysis results. The model's predictive performance was evaluated using calibration curves, C-index, and ROC curves, and internal validation was performed using the bootstrap method.

Results

LASSO analysis identified 28 potential risk factors. Multivariate analysis showed that age, gender, TC, ALB, MCV, FIB, PDW, LYM, hemoptysis, and hypertension are independent risk factors for bronchiectasis patients with APTB (p < 0.05). The nomogram demonstrated strong calibration and discrimination, with a C-index of 0.745 (95% CI: 0.715-0.775) and an AUC of 0.744 for the ROC curve. Internal validation using the bootstrap method produced a C-index of 0.738, further confirming the model's robustness.

Conclusion

The nomogram model, developed using common clinical serological characteristics, holds significant clinical value for assessing the risk of APTB in bronchiectasis patients.

Fungal melanin suppresses airway epithelial chemokine secretion through blockade of calcium fluxing

Respiratory infections caused by the human fungal pathogen Aspergillus fumigatus are a major cause of mortality for immunocompromised patients. Exposure to these pathogens occurs through inhalation, although the role of the respiratory epithelium in disease pathogenesis has not been fully defined. Employing a primary human airway epithelial model, we demonstrate that fungal melanins potently block the post-translational secretion of the chemokines CXCL1 and CXCL8 independent of transcription or the requirement of melanin to be phagocytosed, leading to a significant reduction in neutrophil recruitment to the apical airway both in vitro and in vivo. Aspergillus-derived melanin, a major constituent of the fungal cell wall, dampened airway epithelial chemokine secretion in response to fungi, bacteria, and exogenous cytokines. Furthermore, melanin muted pathogen-mediated calcium fluxing and hindered actin filamentation. Taken together, our results reveal a critical role for melanin interaction with airway epithelium in shaping the host response to fungal and bacterial pathogens.

Bronchiectasis

Non-cystic fibrosis bronchiectasis, a condition that remains relatively underrecognized, has garnered increasing research focus in recent years. This scientific interest has catalyzed advancements in diagnostic methodologies, enabling comprehensive clinical and molecular profiling. Such progress facilitates the development of personalized treatment strategies, marking a significant step toward precision medicine for these patients. Bronchiectasis poses significant diagnostic challenges in both clinical settings and research studies. While computed tomography (CT) remains the gold standard for diagnosis, novel alternatives are emerging. These include artificial intelligence-powered algorithms, ultra-low dose chest CT, and magnetic resonance imaging (MRI) techniques, all of which are becoming recognized as feasible diagnostic tools. The precision medicine paradigm calls for refined characterization of bronchiectasis patients by analyzing their inflammatory and molecular profiles. Research into the underlying mechanisms of inflammation and the evaluation of biomarkers such as neutrophil elastase, mucins, and antimicrobial peptides have led to the identification of distinct patient endotypes. These endotypes present variable clinical outcomes, necessitating tailored therapeutic interventions. Among these, eosinophilic bronchiectasis is notable for its prevalence and specific prognostic factors, calling for careful consideration of treatable traits. A deeper understanding of the microbiome's influence on the pathogenesis and progression of bronchiectasis has inspired a holistic approach, which considers the multibiome as an interconnected microbial network rather than treating pathogens as solitary entities. Interactome analysis therefore becomes a vital tool for pinpointing alterations during both stable phases and exacerbations. This array of innovative approaches has revolutionized the personalization of treatments, incorporating therapies such as inhaled mannitol or ARINA-1, brensocatib for anti-inflammatory purposes, and inhaled corticosteroids specifically for patients with eosinophilic bronchiectasis.

Fungal melanin suppresses airway epithelial chemokine secretion through blockade of calcium fluxing

Respiratory infections caused by the human fungal pathogen Aspergillus fumigatus are a major cause of mortality for immunocompromised patients. Exposure to these pathogens occurs through inhalation, although the role of the respiratory epithelium in disease pathogenesis has not been fully defined. Employing a primary human airway epithelial model, we demonstrate that fungal melanins potently block the post-translational secretion of the chemokines CXCL1 and CXCL8 independent of transcription or the requirement of melanin to be phagocytosed, leading to a significant reduction in neutrophil recruitment to the apical airway both in vitro and in vivo . Aspergillus -derived melanin, a major constituent of the fungal cell wall, dampened airway epithelial chemokine secretion in response to fungi, bacteria, and exogenous cytokines. Furthermore, melanin muted pathogen-mediated calcium fluxing and hindered actin filamentation. Taken together, our results reveal a critical role for melanin interaction with airway epithelium in shaping the host response to fungal and bacterial pathogens.

Does asthma-bronchiectasis overlap syndrome (ABOS) really exist?

OBJECTIVE

To analyze the relationship between asthma and bronchiectasis, as well as the necessary conditions that this connection must meet for this group of patients to be considered a special phenotype.

DATA SOURCES

We performed a PubMed search using the MeSH terms "asthma" and "bronchiectasis." The literature research was limited to clinical trials, meta-analyses, randomized controlled trials, cohort studies, and systematic reviews, involving adult patients, published until November 30th, 2022.

STUDY SELECTIONS

Selected papers were initially evaluated by the Authors, to assess their eligibility in contributing to the statements.

RESULTS

The prevalence of bronchiectasis is higher than expected in patients with asthma, particularly in those with more severe disease, and in some patients, between 1.4% and 7% of them, asthma alone could be the cause of bronchiectasis. Both diseases share etiopathogenic mechanisms, such as neutrophilic and eosinophilic inflammation, altered airway microbiota, mucus hypersecretion, allergen sensitization, immune dysfunction, altered microRNA, dysfunctional neutrophilic activity, and variants of the HLA system. Besides that, they also share comorbidities, such as gastroesophageal reflux disease and psychiatric illnesses. The clinical presentation of asthma is very similar to patients with bronchiectasis, which could cause mistakes with diagnoses and delays in being prescribed the correct treatment. The coexistence of asthma and bronchiectasis also poses difficulties for the therapeutic focus.

CONCLUSIONS

The evidence available seems to support that the asthma-bronchiectasis phenotype really exists although longitudinal studies which consistently demonstrate that asthma is the cause of bronchiectasis are still lacking.

Bronchiectasis-COPD Overlap Syndrome: Role of Peripheral Eosinophil Count and Inhaled Corticosteroid Treatment

Both chronic obstructive pulmonary disease and bronchiectasis are highly prevalent diseases. In both cases, inhaled corticosteroids (ICs) are associated with a decrease in exacerbations in patients with a high peripheral blood eosinophil count (BEC), but it is still not known what occurs in bronchiectasis-COPD overlap syndrome (BCOS). The present study aimed to assess the effect of ICs on various outcomes in patients with BCOS, according to BEC values. We undertook a post-hoc analysis of a cohort of 201 GOLD II-IV COPD patients with a long-term follow-up (median 74 [IQR: 40-106] months). All participants underwent computerized tomography and 115 (57.2%) had confirmed BCOS. A standardized clinical protocol was followed and two sputum samples were collected at each medical visit (every 3-6 months), whenever possible. During follow-up, there were 68 deaths (59.1%), and the mean rate of exacerbations and hospitalizations per year was 1.42 (1.2) and 0.57 (0.83), respectively. A total of 44.3% of the patients presented at least one pneumonic episode per year. The mean value of eosinophils was 402 (112) eosinophils/µL, with 27 (23.5%), 63 (54.8%), and 25 patients (21.7%) presenting, respectively, less than 100, 101-300, and more than 300 eosinophils/µL. A total of 84 patients (73.1%) took ICs. The higher the BEC, the higher the annual rate of exacerbations and hospitalizations. Patients with less than 100 eosinophils/µL presented more infectious events (incident exacerbations, pneumonic episodes, and chronic bronchial infection via pathogenic bacteria). Only those patients with eosinophilia (>300 eosinophils/µL) treated with ICs decreased the number (1.77 (1.2) vs. 1.08 (0.6), p < 0.001) and the severity (0.67 (0.8) vs. 0.35 (0.5), p = 0.011) of exacerbations, without any changes in the other infectious outcomes or mortality. In conclusion, ICs treatment in patients with BCOS with increased BEC decreased the number and severity of incident exacerbations without any negative influence on other infectious outcomes (incidence of pneumonia or chronic bronchial infection).

Etiology of Bronchiectasis in the World: Data from the Published National and International Registries

Bronchiectasis is the third leading chronic inflammatory disease of the airway caused by dozens of pulmonary and extra-pulmonary diseases. Infection by pathogenic microorganisms is very common. We aimed to analyze, for the first time in the literature, the etiology of bronchiectasis throughout the world via data published in national and international registries. A bibliographic search was carried out in PubMed and Web of Science. Seven studies were included, with a total of 27,258 patients from 33 countries of four continents. The most frequent cause of bronchiectasis was post-infectious: 30.5% (range: 19.1-40.4%), followed by idiopathic: 28.7% (18.5-38.1%). Post-tuberculous bronchiectasis accounted for 14.1% (1.8-35.5%), while etiologies associated with COPD and asthma comprised 7% (3.4-10.9%) and 5.2% (2.5-7.8%). In conclusion, there was a high degree of heterogeneity in the relative percentages of the main causes of bronchiectasis in the world, although post-infectious and idiophatic bronchiectasis continue to be the most frequent causes.

The U-Shaped Relationship Between Eosinophil Count and Bronchiectasis Severity: The Effect of Inhaled Corticosteroids

BACKGROUND

Although a proven relationship exists between the blood eosinophil count (BEC) and the severity of both asthma and COPD, its relationship with bronchiectasis has not been well established. The objective of this study was to analyze the relationship between BEC and the number and severity of exacerbations, and patients' responses to inhaled corticosteroid (IC) treatment in bronchiectasis RESEARCH QUESTION: Does an association exist among BEC, the number of exacerbations and severity of bronchiectasis, and IC treatment?

STUDY DESIGN AND METHODS

This was a multicenter (43 centers) prospective observational study derived from the Spanish Bronchiectasis Registry. Patients with proven bronchiectasis and a known BEC were included, whereas those with asthma or antieosinophilic treatments were excluded. Patients were divided into four groups according to the BEC at the time of inclusion in the study in a steady-state situation: (1) eosinopenic bronchiectasis (< 50 eosinophils/μL), (2) low number of eosinophils (51-100/μL), (3) normal number of eosinophils (101-300/μL), and (4) eosinophilic bronchiectasis (> 300 eosinophils/μL).

RESULTS

Nine hundred twenty-eight patients finally were included: 123 patients (13.3%) with < 50 eosinophils/μL (eosinopenic group), 164 patients (17.7%) with 50-100 eosinophils/μL, 488 patients (52.6%) with 101-300 eosinophils/μL, and 153 patients (16.5%) with > 300 eosinophils/μL (eosinophilic group). BEC showed a significant U-shaped relationship with severity, exacerbations, lung function, microbiologic profile, and IC treatment (these being higher in the eosinopenic group compared with the eosinophilic group). IC treatment significantly decreased the number and severity of exacerbations only in the group of bronchiectasis patients with > 300 eosinophils/μL.

INTERPRETATION

A significant U-shaped relationship was found between BEC and severity and exacerbations in bronchiectasis that was more pronounced in the eosinopenic group. IC treatment decreased the number and severity of exacerbations only in the eosinophilic group.

Isolation of Pseudomonas aeruginosa in Stable Chronic Obstructive Pulmonary Disease Patients-Should We Treat It?

Chronic obstructive pulmonary disease (COPD) is one of the most frequent inflammatory diseases of the airways [...].

Novel Anti-Inflammatory Approaches to COPD

Airway inflammation, driven by different types of inflammatory cells and mediators, plays a fundamental role in COPD and its progression. Neutrophils, eosinophils, macrophages, and CD4+ and CD8+ T lymphocytes are key players in this process, although the extent of their participation varies according to the patient's endotype. Anti-inflammatory medications may modify the natural history and progression of COPD. However, since airway inflammation in COPD is relatively resistant to corticosteroid therapy, innovative pharmacological anti-inflammatory approaches are required. The heterogeneity of inflammatory cells and mediators in annethe different COPD endo-phenotypes requires the development of specific pharmacologic agents. Indeed, over the past two decades, several mechanisms that influence the influx and/or activity of inflammatory cells in the airways and lung parenchyma have been identified. Several of these molecules have been tested in vitro models and in vivo in laboratory animals, but only a few have been studied in humans. Although early studies have not been encouraging, useful information emerged suggesting that some of these agents may need to be further tested in specific subgroups of patients, hopefully leading to a more personalized approach to treating COPD.

Efficacy and Safety of Dry Powder Antibiotics: A Narrative Review

The use of inhaled antibiotics was initially almost exclusively confined to patients with cystic fibrosis (CF). However, it has been extended in recent decades to patients with non-CF bronchiectasis or chronic obstructive pulmonary disease who present with chronic bronchial infection by potentially pathogenic microorganisms. Inhaled antibiotics reach high concentrations in the area of infection, which enhances their effect and enables their long-term administration to defeat the most resistant infections, while minimizing possible adverse effects. New formulations of inhaled dry powder antibiotics have been developed, providing, among other advantages, faster preparation and administration of the drug, as well as avoiding the requirement to clean nebulization equipment. In this review, we analyze the advantages and disadvantages of the different types of devices that allow the inhalation of antibiotics, especially dry powder inhalers. We describe their general characteristics, the different inhalers on the market and the proper way to use them. We analyze the factors that influence the way in which the dry powder drug reaches the lower airways, as well as aspects of microbiological effectiveness and risks of resistance development. We review the scientific evidence on the use of colistin and tobramycin with this type of device, both in patients with CF and with non-CF bronchiectasis. Finally, we discuss the literature on the development of new dry powder antibiotics.

Inhaled Corticosteroids and Bronchiectasis: Friend or Foe?

The three most common chronic inflammatory airway diseases are asthma, chronic obstructive pulmonary disease (COPD), and bronchiectasis [...].