CT Mucus Score and 129Xe MRI Ventilation Defects After 2.5 Years' Anti-IL-5Rα in Eosinophilic Asthma

Computed tomography in severe asthma assessment: a systematic review

OBJECTIVE

Chest computed tomography (CT) is usually performed in patients with severe asthma (SA) to exclude concomitant conditions related to poor clinical control. Despite the growing evidence regarding the utility of CT in the characterization of morphological abnormalities and airway remodeling, its role in SA assessment is still largely unexplored. The aim of our systematic review was to evaluate published data investigating the role of chest CT in patients with SA.

DATA SOURCES

The systematic search was conducted on the Medline database through the Pubmed search engine.

STUDY SELECTIONS

A total of 53 studies has been included.

RESULTS

Quantitative CT (qCT) parameters generally differ between SA patients compared to mild to moderate asthmatic patients or healthy controls and are related to functional decline. CT parameters allow to identify image-based clusters reflecting remodeling patterns and/or air trapping features. The detection of mucus plugs is more frequent in severe eosinophilic asthma, and it is related to marked airway obstruction and ventilation defects. Benralizumab treatment appears to reduce or vanish mucus plugging. Most studies regarding CT and bronchial thermoplasty (BT) detect the usefulness of this investigation in predicting treatment response. Lastly, conflicting results surround the relation between chest CT and SA assessment in children due to also the scarcity of studies focusing on pediatric population.

CONCLUSIONS

The role of CT scans in SA is still debated. Most studies focus on the identification of CT-derived disease clusters while studies primarily evaluating the predicting role of CT scan to different biologics are lacking and could represent an interesting research area.

Quantification of 129Xe MRI Ventilation-defect-percent Using Binary-threshold, Gaussian Linear-Binning and K-means Methods: Differences in Asthma and COPD

RATIONALE AND OBJECTIVES

Hyperpolarized 129Xe magnetic resonance imaging (MRI) provides a way to quantify ventilation heterogeneity as ventilation defect percent (VDP), calculated as the volume of unventilated lung volume normalized to the thoracic cavity volume. Currently used methods for quantifying VDP include (1) binary signal-intensity thresholds (Binary-threshold, BT), (2) Gaussian transformation of signal-intensity histogram with standard deviation thresholds or Gaussian-linear-binning (GLB), and (3) iterative centroid-based clustering of the signal-intensity histogram (k-means). These methods have not been directly compared in patients with asthma and chronic obstructive pulmonary disease (COPD), in whom ventilation defects are hallmark findings. Our objective was to quantify and compare VDP using these four different methods.

PATIENTS AND METHODS

Data from 175 participants (n=42 healthy, n=43 COPD, n=90 asthma) were retrospectively evaluated using a CNN co-registration and segmentation pipeline and GLB, GLBslice, (slice-wise evaluation of GLB) BT and k-means VDP quantification methods. Linear-regression and Bland-Altman plots were used to quantify inter-method correlations and agreement.

RESULTS

VDP was significantly different using GLB (Asthma: 6±9%, COPD: 7±7%, p<.001) and BT (Asthma: 6±7%, COPD: 10±8%, p<.001) methods compared to GLBslice (Asthma: 12±13%, COPD: 16±15%, p<.001) and k-means (Asthma: 12±12%, COPD: 25±17%, p<.001). VDP calculated using GLB (R2=.64, p<.001), GLBslice (R2=.84, p<.001) and BT (R2=.84, p<.001) was significantly correlated with k-means VDP. Bland-Altman plots revealed wide 95% confidence intervals of agreement for k-means with GLB/GLBslice (COPD -6%/-1%: 42%/23%; asthma -5%/-10%:16%/10%) and BT (COPD -4%:36%; asthma -6%:19%).

CONCLUSION

VDP differences in patients with asthma and COPD calculated using four methods are important to consider for multi-center studies.

Recent advances in asthma mucus biology and emerging treatment strategies

PURPOSE OF REVIEW

To describe the recent advances in the pathobiology and treatment of mucus hypersecretion in asthma, a critical factor contributing to airway obstruction, inflammation, and impaired lung function.

RECENT FINDINGS

Significant progress has been made in understanding how mucin protein regulation, mucus viscosity, and adhesion are affected by cytokine-driven inflammation, especially interleukin-13, and defects in ion transport mechanisms. Advances in imaging techniques, such as multidetector computed tomography (MDCT) and hyperpolarized gas MRI, allow for a more precise assessment of mucus plugging and associated ventilation defects. Emerging therapies, including biologicals targeting type-2 (T2) inflammation, and novel mucolytics aimed at modifying mucus properties and secretion, offer promising effects in reducing mucus in severe asthmatics.

SUMMARY

The growing understanding of mucus biology and the development of advanced imaging and therapeutic strategies could significantly improve the management of mucus-related complications in asthma. By targeting mucus characteristics, these findings support future approaches to reduce airway obstruction, enhance lung function, and improve clinical outcomes in patients with severe asthma. A deeper understanding of the glycobiology of mucus is critical to develop new therapies.

Long-Term Clinical Remission on Benralizumab Treatment in Severe Eosinophilic Asthma: A Four-Year Real-Life Study

Background: The current availability of monoclonal antibodies against key mediators of type-2 (T2) inflammation has led to a redefinition of the ultimate objectives of severe asthma treatment to a more composite concept of disease remission. Objectives: The aim of this real-life study was to estimate the percentage of patients who achieved clinical remission over 4 years of treatment with benralizumab, and to identify baseline predictors for the achievement of such a composite outcome in the long term. Methods: Data from a 4-year follow-up of 23 patients who were prescribed benralizumab as an add-on therapy because of uncontrolled severe eosinophilic asthma were retrospectively analyzed and compared. Clinical remission was considered to be "complete" if oral corticosteroid (OCS) use was not required, there were no exacerbations, an asthma control test (ACT) score ≥ 20 was achieved and a pre-bronchodilation percent predicted a forced expiratory volume in 1 s (FEV1%) ≥ 80%. Clinical remission was considered to be "partial" if OCS use was not required, plus at least two of the other three aforementioned criteria. Results: The overall percentage of patients who achieved clinical remission was 86.9% after 12 months, and 91.3% after 24 and 48 months of treatment. The rate of complete remission over partial remission increased over time. After 12 months of treatment, 65% of patients fulfilled the criteria for complete remission and 35.0% for partial remission. After 48 months of treatment, 71.4% of patients were in a status of complete remission and 28.6% in a status of partial remission. A long-term composite outcome of complete clinical remission was more likely to be achieved by severe eosinophilic asthma patients with comorbid nasal polyposis, bronchiectasis and osteoporosis, and with OCS dependency, a predicted pre-bronchodilation FEV1% ≥ 80% and a predicted FEF25-75% < 65% at baseline. Conclusions: Our real-life experience suggests that treatment with benralizumab may allow the achievement and long-term maintenance of clinical remission in a high percentage of severe eosinophilic asthma patients, up to 4 years of follow-up.

Effect of dupilumab on exhaled nitric oxide, mucus plugs, and functional respiratory imaging in patients with type 2 asthma (VESTIGE): a randomised, double-blind, placebo-controlled, phase 4 trial

BACKGROUND

Asthma is a respiratory disease characterised by chronic airway inflammation and mucus hypersecretion. VESTIGE used functional respiratory imaging to assess changes in airway structure and function, including mucus plugging, in response to dupilumab.

METHODS

VESTIGE was a randomised, double-blind, placebo-controlled, phase 4 trial done at 72 research sites or academic centres in 14 countries. We recruited adult patients (aged 18-70 years) with physician-diagnosed, uncontrolled, moderate-to-severe type 2 asthma (blood eosinophil count ≥300 cells/μL and fractional exhaled nitric oxide [FeNO] ≥25 parts per billion [ppb]) being treated with medium-dose to high-dose inhaled corticosteroids combined with other controller medications. Patients were randomly assigned (2:1; block size of 6) via interactive voice-web response technology to receive add-on dupilumab 300 mg subcutaneously once every 2 weeks or volume-matched placebo up to week 24. Randomisation was stratified by inhaled corticosteroids dose level and region (eastern Europe vs the rest of the world). Participants and investigators, including those assessing outcomes, were masked to group assignment. The primary endpoints were the proportion of patients with a FeNO concentration below 25 ppb at week 24, and percentage change from baseline to week 24 in airway volumes (specific regional airway volumes corrected for lung volume, [s]iVaw) at total lung capacity (TLC), both assessed in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study drug or placebo. The trial is registered with ClinicalTrials.gov, NCT04400318, and is completed.

FINDINGS

Patient recruitment occurred from July 18, 2020, to Jan 6, 2023. Patients (mean age 50·4 years [SD 12·6]; 68 [62%] female and 41 [38%] male) were randomly assigned to receive dupilumab 300 mg (n=72) or placebo (n=37). At week 24, patients in the dupilumab group were significantly more likely than those in the placebo group to have a FeNO concentration below 25 ppb (41 [57%] of 72 patients vs four [11%] of 37; odds ratio: 9·8 [95% CI 3·1 to 30·8]; p<0·001). Treatment with dupilumab versus placebo led to a numerical increase in (s)iVaw at TLC from baseline to week 24, although the difference was not significant (least squares [LS] mean percentage change from baseline to week 24: 19·7% [SE 8·1] for dupilumab and -2·0% [11·5] for placebo; LS mean difference vs placebo: 21·8% [95% CI -7·7 to 51·3]; p=0·14). Safety was consistent with the reported safety profile for dupilumab. Treatment-emergent adverse events related to study intervention were reported in 11 (15%) of 72 patients who received dupilumab and four (11%) of 37 who received placebo; no deaths occurred during the intervention period.

INTERPRETATION

The full results of this study indicate that dupilumab reduced airway inflammation and mucus plugging, and improved airway volume and flow, corresponding to improved lung function and asthma control. This study highlights the potential of imaging technology to assess disease burden, monitor progression, and evaluate therapeutic responses, which can provide valuable insights to guide clinical decision making for patients with uncontrolled, moderate-to-severe type 2 asthma.

FUNDING

Sanofi and Regeneron Pharmaceuticals.

Out of Breath, out of Options: Benralizumab as a Last Hope in ICU-Treated Near-Fatal Eosinophilic Asthma: A Case Series

Asthma exacerbations remain life-threatening events despite advancements in biologic therapies. This case series reports on four patients with near-fatal eosinophilic asthma exacerbations who had been admitted to intensive care and were treated with benralizumab as a last resort after failing maximal standard therapies. All patients exhibited marked blood or airway eosinophilia and required intensive care ventilatory support. Following the administration of benralizumab, significant clinical improvements were observed. This series highlights the potential role of benralizumab in treating life-threatening asthma exacerbations driven by eosinophilic airway inflammation and underlines the need for phenotyping and timely intervention in managing such patients with near-fatal asthma while also stressing the need for continued adherence to asthma guidelines to prevent these extreme situations.

Biologics and airway remodeling in asthma: early, late, and potential preventive effects

Although airway remodeling in severe and/or fatal asthma is still considered irreversible, its individual components as a cause of clinical symptoms and/or lung function changes remain largely unknown. While inhaled glucocorticoids have not consistently been shown to affect airway remodeling, biologics targeting specific pathways of airway inflammation have been shown to improve lung function, mucus plugging, and airway structural changes that can exceed those seen with glucocorticoids. This superiority of biologic treatment, which cannot be solely explained by insufficient doses or limited durations of glucocorticoid therapies, needs to be further explored. For this field of research, we propose a novel classification of the potential effects of biologics on airway remodeling into three temporal effects: early effects (days to weeks, primarily modulating inflammatory processes), late effects (months to years, predominantly affecting structural changes), and potential preventive effects (outcomes of early treatment with biologics). For the identification of potential preventive effects of biologics, we call for studies exploring the impact of early biological treatment on airway remodeling in patients with moderate-to-severe asthma, which should be accompanied by a long-term evaluation of clinical parameters, biomarkers, treatment burden, and socioeconomic implications.

Baseline forced oscillation technique predicting lack of exacerbations in adult patients with asthma: A 12-month prospective

BACKGROUND

The forced oscillation technique (FOT) is a minimally invasive test to evaluate asthma during resting ventilation. However, its role in longitudinal assessments, such as clinical remission, remains unclear.

OBJECTIVE

To longitudinally assess asthma clinical remission and identify parameters that predict clinical remission at 12 months from baseline FOT.

METHODS

Adult patients with asthma at our university hospital between April 2022 and May 2023 were enrolled in this prospective observational study. They were evaluated for 12 months after enrollment to determine whether they met the following clinical remission criteria: asthma control test score of more than or equal to 20 at enrollment and 12 months, no asthma exacerbations for 12 months, and no regular oral corticosteroid use during the 12 months. FOT parameters at enrollment were analyzed for associations with clinical remission.

RESULTS

A total of 94 patients with asthma completed the study and were categorized into clinical and nonclinical remission groups. Comparison of pulmonary function tests, including the FOT, between the 2 groups revealed significant differences in resistance at 5 Hz and resistance at 20 Hz (R20) but not in forced expiratory volume in 1 second. Multivariate logistic regression analysis revealed that R20 was associated with clinical remission, with adjusted odds ratios of 0.32 (95% CI: 0.12-0.91, P = .033) for R20.

CONCLUSION

R20 can be a useful predictor of future exacerbations in patients with asthma. These findings may assist in evaluating adult patients with asthma and normal forced expiratory volume in 1 second.

Real-world effectiveness of mepolizumab in Japanese asthma patients with diverse backgrounds: Improvements in rhinosinusitis imaging (J-Real-Mepo)

BACKGROUND

Although randomized controlled trials (RCT) have demonstrated the efficacy of mepolizumab for asthma, they have excluded certain patient subgroups. To bridge the gap between RCT and real-world practice, the effectiveness of mepolizumab in a diverse population, including those potentially excluded from RCT, was assessed. Its effects on imaging findings and symptoms of chronic rhinosinusitis (CRS) with asthma were also assessed.

METHODS

This retrospective observational study of patients in Japan (J-Real-Mepo: UMIN000045021) evaluated multiple endpoints and analyzed the relationship between clinical background and treatment outcomes.

RESULTS

Mepolizumab significantly reduced exacerbations, improved Asthma Control Test (ACT) scores, and forced expiratory volume in 1 s, and reduced oral corticosteroid (OCS) dose, regardless of patient characteristics, including age, body mass index, smoking history, and comorbidities. Regarding RCT exclusion criteria, 29.4 % of patients had no history of exacerbations. Although 25.4 % of these patients required continuous OCS, the OCS dose was reduced similar to those with a history of exacerbations. Disease control and mepolizumab effectiveness in patients with a smoking history ≥10 pack-years was similar to that of never-smokers. Patients with eosinophil counts <150/μL had lower ACT scores and higher OCS use compared with patients with eosinophilia and comparable effectiveness regarding exacerbation and OCS reduction. Significant improvements in Lund-Mackay scores and CRS symptoms were observed.

CONCLUSIONS

Mepolizumab effectiveness was demonstrated in a broad range of patients including those with RCT exclusion criteria, who had significant disease or OCS burden. These findings may explain the consistent results between RCT and real-world studies of mepolizumab.

Airway Remodeling in Asthma: Mechanisms, Diagnosis, Treatment, and Future Directions

Airway remodeling (AR) with chronic inflammation, are key features in asthma pathogenesis. AR characterized by structural changes in the bronchial wall is associated with a specific asthma phenotype with poor clinical outcomes, impaired lung function and reduced treatment response. Most studies focus on the role of inflammation, while understanding the mechanisms driving AR is crucial for developing disease-modifying therapeutic strategies. This review paper summarizes current knowledge on the mechanisms underlying AR, diagnostic tools, and therapeutic approaches. Mechanisms explored include the role of the resident cells and the inflammatory cascade in AR. Diagnostic methods such as bronchial biopsy, lung function testing, imaging, and possible biomarkers are described. The effectiveness on AR of different treatments of asthma including corticosteroids, leukotriene modifiers, bronchodilators, macrolides, biologics, and bronchial thermoplasty is discussed, as well as other possible therapeutic options. AR poses a significant challenge in asthma management, contributing to disease severity and treatment resistance. Current therapeutic approaches target mostly airway inflammation rather than smooth muscle cell dysfunction and showed limited benefits on AR. Future research should focus more on investigating the mechanisms involved in AR to identify novel therapeutic targets and to develop new effective treatments able to prevent irreversible structural changes and improve long-term asthma outcomes.

Molecular mechanisms and clinical impact of biologic therapies in severe asthma

Severe asthma is a critical condition for patients with asthma, characterized by frequent exacerbations, decreased pulmonary function, and unstable symptoms related to asthma. Consequently, the administration of systemic corticosteroids, which cause secondary damage because of their adverse effects, is considered. Recently, several types of molecular-targeted biological therapies have become available for patients with severe asthma, and they have a capacity to improve the pathophysiology of severe asthma. However, several clinical reports indicate that the effects differ depending on the biological targets of asthma in individual patients. In this review, the molecular mechanisms and clinical impact of biologic therapies in severe asthma are described. In addition, molecules targeted by possible future biologics are also addressed. Better understanding of the mechanistic basis for the role of biologics in severe asthma could lead to new therapeutic options for these patients.

Identifying super-responders: A review of the road to asthma remission

Asthma is a chronic respiratory disease marked by heterogeneity and variable clinical outcomes. Recent therapeutic advances have highlighted patients achieving optimal outcomes, termed "remission" or "super-response." This review evaluates the various definitions of these terms and explores how disease burden impedes the attainment of remission. We assessed multiple studies, including a recent systematic review and meta-analysis, on biologic treatments for asthma remission. Our review highlights that type 2 inflammation may be the strongest predictor of biologic response. Key comorbidities (eg, obesity and mood disorders) and behavioral factors (eg, poor adherence, improper inhalation technique, and smoking) were identified as dominant traits limiting remission. In addition, asthma burden and longer disease duration significantly restrict the potential for remission in patients with severe asthma under the current treatment paradigm. We review the potential for a "predict-and-prevent" approach, which focuses on early identification of high-risk patients with type 2 inflammation and aggressive treatment to improve long-term asthma outcomes. In conclusion, this scoping review highlights the following unmet needs in asthma remission: (1) a harmonized global definition, with better defined lung function parameters; (2) integration of nonbiologic therapies into remission strategies; and (3) a clinical trial of early biologic intervention in patients with remission-prone, very type 2-high, moderately severe asthma with clinical remission as a predefined primary end point.

A protocol for a Japanese prospective cohort evaluating the features of patients with uncontrolled asthma achieving clinical remission: J-CIRCLE

BACKGROUND

Increasing expectations that biologics can be used as disease-modifying agents have introduced the concept of clinical remission (CR) in managements of severe asthma. Given the clinical relevance of computed tomography (CT) and blood biomarkers, we hypothesized that further refinement of CR criteria as well as incorporation of CT and blood biomarkers as indicators for structural and biological remission (SR, BR) would enable predicting long-term disease stability in patients with severe asthma treated with biologics.

METHODS

This Japanese multicenter prospective observational cohort will enroll patients with severe asthma who will start a new biologic (including a change from another biologic). The enrolled patients will be longitudinally followed up for 3 years. At enrollment, patients will undergo postbronchodilator spirometry, blood tests, fractional exhaled nitric oxide, chest and sinus CT, and patient-reported outcome questionnaires. Follow-up examinations will be performed at 1, 3, 6, 12, 24, and 36 months. The rates of CR resulting from different criteria after 1 year of treatment with biologics will be compared, and factors associated with long-term disease stability after 3 years of biologic treatments will be identified.

DISCUSSION

This multicenter study in Japan will provide data that will help establish more appropriate criteria for CR, structural remission, and biological remission to predict long-term disease stability in patients with severe asthma who receive biologic therapy.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of Kyoto University (No. R4419, approval date June 11th, 2024).

TRIAL REGISTRATION

The University Hospital Medical Information Network (UMIN000053771).

Lung imaging in COPD and asthma

Chronic obstructive pulmonary disease (COPD) and asthma are common lung diseases with heterogeneous clinical presentations. Lung imaging allows evaluations of underlying pathophysiological changes and provides additional personalized approaches for disease management. This narrative review provides an overview of recent advances in chest imaging analysis using various modalities, such as computed tomography (CT), dynamic chest radiography, and magnetic resonance imaging (MRI). Visual CT assessment localizes emphysema subtypes and mucus plugging in the airways. Dedicated software quantifies the severity and spatial distribution of emphysema and the airway tree structure, including the central airway wall thickness, branch count and fractal dimension of the tree, and airway-to-lung size ratio. Nonrigid registration of inspiratory and expiratory CT scans quantifies small airway dysfunction, local volume changes and shape deformations in specific regions. Lung ventilation and diaphragm movement are also evaluated on dynamic chest radiography. Functional MRI detects regional oxygen transfer across the alveolus using inhaled oxygen and ventilation defects and gas diffusion into the alveolar-capillary barrier tissue and red blood cells using inhaled hyperpolarized 129Xe gas. These methods have the potential to determine local functional properties in the lungs that cannot be detected by lung function tests in patients with COPD and asthma. Further studies are needed to apply these technologies in clinical practice, particularly for early disease detection and tailor-made interventions, such as the efficient selection of patients likely to respond to biologics. Moreover, research should focus on the extension of healthy life expectancy in patients at higher risk and with established diseases.

Clinical characteristics and factors associated with mucus plugs under bronchoscopy in children hospitalized for acute asthma attack

Objective

To describe clinical characteristics of hospitalized children with acute asthma attacks complicated with mucus plugs and to investigate the factors associated with mucus plugs in asthma children.

Methods

This retrospective study analyzed hospitalized children and adolescents with acute asthma attacks from January 2016 to December 2021. The demographic information and characteristics were collected. Subjects were categorized into the mucus plug group and the control group based on the bronchoalveolar lavage results. The Logistic regression analyses were utilized to assess the relative factors associated with mucus plugs. All data were analyzed using SPSS 22.0.

Results

This study included 242 individuals. Out of the 151 subjects who underwent bronchoscopy, 62.9% were classified in the mucus plug group and 37.1% in the control group. The subjects with dyspnea had a higher proportion in the mucus plug group (52.6% vs. 26.8%). The serum total IgE level of the mucus plug group was lower than the control group. The proportion of subjects who were diagnosed with asthma for the first time during hospitalization (87.4% vs. 76.8%) and combined with respiratory infection (91.6% vs. 82.1%) in the mucus plug group might be higher than that in the control group. More subjects in the mucus plug group were administered systemic glucocorticoid, magnesium sulfate, aminophylline, and mucolytic drugs after hospitalization. In multivariable analysis, diagnosed with asthma for the first time during hospitalization (OR = 4.404; 1.101-17.614), dyspnea (OR = 4.039; 1.306-12.496), and cesarean (OR = 0.274; 0.092-0.812) might be associated with mucus plug in children hospitalized for an acute asthma attack.

Suggests

While our retrospective study suggests that some clinical features of children hospitalized with asthma who have mucus plugs differ from those without, further studies are required.

The epithelial era of asthma research: knowledge gaps and future direction for patient care

The Epithelial Science Expert Group convened on 18-19 October 2023, in Naples, Italy, to discuss the current understanding of the fundamental role of the airway epithelium in asthma and other respiratory diseases and to explore the future direction of patient care. This review summarises the key concepts and research questions that were raised. As an introduction to the epithelial era of research, the evolution of asthma management throughout the ages was discussed and the role of the epithelium as an immune-functioning organ was elucidated. The role of the bronchial epithelial cells in lower airway diseases beyond severe asthma was considered, as well as the role of the epithelium in upper airway diseases such as chronic rhinosinusitis. The biology and application of biomarkers in patient care was also discussed. The Epithelial Science Expert Group also explored future research needs by identifying the current knowledge and research gaps in asthma management and ranking them by priority. It was identified that there is a need to define and support early assessment of asthma to characterise patients at high risk of severe asthma. Furthermore, a better understanding of asthma progression is required. The development of new treatments and diagnostic tests as well as the identification of new biomarkers will also be required to address the current unmet needs. Finally, an increased understanding of epithelial dysfunction will determine if we can alter disease progression and achieve clinical remission.

Imaging in Pediatric Lung Disease: Current Practice and Future Directions

Pediatric diseases present differently from adult diseases and imaging forms a cornerstone of modern pediatric care through differential diagnosis, disease monitoring, and measuring response to therapy. Imaging is especially well suited to providing novel insights into the underlying mechanisms driving disease through structural and functional imaging. In this review, we describe key imaging findings in standard-of-care and state-of-the-art techniques in pediatric and adult diseases with origins in childhood. We examine applications in small airways disease, large airway disease, diseases of maturity, interstitial lung disease, neuromuscular disease, congenital disease, and pulmonary infection.

Benralizumab-resistant mucus plugs in severe asthma complicated by eosinophilic chronic rhinosinusitis

It is an absolute necessity to achieve complete control of comorbidities to obtain optimal asthma control. Importantly, type 2 asthma and ECRS share the same inflammatory pathophysiology and are common co-morbidities. If the initial biologic is insufficiently effective, it is worth considering an alternative biologic.

Eosinophilic mucus diseases

Eosinophilic inflammation is primarily characterized by type 2 immune responses against parasitic organisms. In the contemporary human being especially in developed countries, eosinophilic inflammation is strongly associated with allergic/sterile inflammation, and constitutes an undesired immune reaction. This situation is in stark contrast to neutrophilic inflammation, which is indispensable for the host defense against bacterial infections. Among eosinophilic inflammatory disorders, massive accumulation of eosinophils within mucus is observed in certain cases, and is often linked to the distinctive clinical finding of mucus with high viscosity. Eosinophilic mucus is found in a variety of diseases, including chronic allergic keratoconjunctivitis, chronic rhinosinusitis encompassing allergic fungal sinusitis, eosinophilic otitis media, eosinophilic sialodochitis, allergic bronchopulmonary aspergillosis/mycosis, eosinophilic plastic bronchitis, and eosinophilic asthma. In these pathological conditions, chronic inflammation and tissue remodeling coupled with irreversible organ damage due to persistent adhesion of toxic substances and luminal obstruction may impose a significant burden on the body. Eosinophils aggregate in the hyperconcentrated mucus together with cell-derived crystals, macromolecules, and polymers, thereby affecting the biophysical properties of the mucus. This review focuses on the clinically significant challenges of mucus and discusses the consequences of activated eosinophils on the mucosal surface that impact mucus and persistent inflammation.

Eosinophil-mucus interplay in severe asthma: Implications for treatment with biologicals

Airway mucus is a hydrogel with unique biophysical properties due to its primary water composition and a small proportion of large anionic glycoproteins or mucins. The predominant mucins in human mucus, MUC5AC and MUC5B, are secreted by specialized cells within the airway epithelium both in normal conditions and in response to various stimuli. Their relative proportions are correlated with specific inflammatory responses and disease mechanisms. The dysregulation of mucin expression is implicated in numerous respiratory diseases, including asthma, COPD, and cystic fibrosis, where the pathogenic role of mucus has been extensively described yet often overlooked. In airway diseases, excessive mucus production or impaired mucus clearance leads to mucus plugging, with secondary airway occlusion that contribute to airflow obstruction, asthma severity and poor control. Eosinophils and Charcot Leyden crystals in sputum contribute to the mucus burden and tenacity. Mucin may also contribute to eosinophil survival. Other mechanisms, including eosinophil-independent IL-13 release, mast-cell activation and non-type-2 (T2) cytokines, are also likely to participate in mucus pathobiology. An accurate assessment of mucus and its clinical and functional consequences require a thorough approach that includes evaluation of cellular predominance in sputum, airway cytokines and other inflammatory markers, mucus characteristics and composition and structural and functional impact measured by advanced lung imaging. This review, illustrated with clinical scenarios, provides an overview of current methods to assess mucus and its relevance to the choice of biologics to treat patients with severe asthma.

Emerging cell and molecular targets for treating mucus hypersecretion in asthma

Mucus provides a protective barrier that is crucial for host defense in the lungs. However, excessive or abnormal mucus can have pathophysiological consequences in many pulmonary diseases, including asthma. Patients with asthma are treated with agents that relax airway smooth muscle and reduce airway inflammation, but responses are often inadequate. In part, this is due to the inability of existing therapeutic agents to directly target mucus. Accordingly, there is a critical need to better understand how mucus hypersecretion and airway plugging are affected by the epithelial cells that synthesize, secrete, and transport mucus components. This review highlights recent advances in the biology of mucin glycoproteins with a specific focus on MUC5AC and MUC5B, the chief macromolecular components of airway mucus. An improved mechanistic understanding of key steps in mucin production and secretion will help reveal novel potential therapeutic strategies.

Type 2 severe asthma: pathophysiology and treatment with biologics

INTRODUCTION

The hallmark of most patients with severe asthma is type 2 inflammation, driven by innate and adaptive immune responses leading to either allergic or non-allergic eosinophilic infiltration of airways. The cellular and molecular pathways underlying severe type 2 asthma can be successfully targeted by specific monoclonal antibodies.

AREAS COVERED

This review article provides a concise overview of the pathophysiology of type 2 asthma, followed by an updated appraisal of the mechanisms of action and therapeutic efficacy of currently available biologic treatments used for management of severe type 2 asthma. Therefore, all reported information arises from a wide literature search performed on PubMed.

EXPERT OPINION

The main result of the recent advances in the field of anti-asthma biologic therapies is the implementation of a personalized medicine approach, aimed to achieve clinical remission of severe asthma. Today this accomplishment is made possible by the right choice of the most beneficial biologic drug for the pathologic traits characterizing each patient, including type 2 severe asthma and its comorbidities.

Unlocking the Long-Term Effectiveness of Benralizumab in Severe Eosinophilic Asthma: A Three-Year Real-Life Study

Background: Benralizumab has been shown to restore good control of severe eosinophilic asthma (SEA). Robust data on benralizumab effectiveness over periods longer than 2 years are scarce. Methods: This retrospective multicentric study was conducted on 108 Italian SEA patients treated with benralizumab for up to 36 months. Partial and complete clinical remission (CR) were assessed. Data were analyzed with descriptive statistics or using linear, logistic, and negative binomial mixed-effect regression models. Results: At 36 months, benralizumab reduced the exacerbation rate by 89% and increased the forced expiratory volume in 1 second (FEV1) (+440 mL at 36 months, p < 0.0001). Benralizumab improved asthma control as well as sinonasal symptoms in patients with chronic rhinosinusitis with nasal polyposis (CRSwNP). Up to 93.33% of patients either reduced or discontinued OCS; benralizumab also decreased ICS use and other asthma medications. Overall, 84.31% of patients achieved partial or complete CR. Conclusions: Benralizumab improved asthma and sinonasal outcomes up to 36 months. These findings support the potential of benralizumab to induce CR, emphasizing its role as a disease-modifying anti-asthmatic drug for the management of SEA. Further research is warranted to expand these findings by minimizing data loss and assessing benralizumab's long-term safety.

Tezepelumab and Mucus Plugs in Patients with Moderate-to-Severe Asthma

BACKGROUND: Mucus plugs in asthmatic airways are associated with airway obstruction and the activity of inflammatory cytokines, specifically interleukin (IL)-5 and IL-13, and they may provide an opportunity for targeted therapy. This analysis of the CASCADE (Study to Evaluate Tezepelumab on Airway Inflammation in Adults With Uncontrolled Asthma) placebo-controlled trial used computed tomography (CT) imaging to assess mucus plugs in patients with moderate-to-severe, uncontrolled asthma who received tezepelumab or placebo. METHODS: CASCADE was an exploratory, double-blind, placebo-controlled trial examining the anti-inflammatory effect of tezepelumab. Patients (aged 18 to 75 years old) were randomly assigned 1:1 to 210 mg tezepelumab or placebo every 4 weeks subcutaneously for at least 28 weeks. An expert radiologist, blinded to treatment groups and time points, objectively scored 18 lung segments for the presence of mucus plugs in CT scans obtained before and after treatment; greater numbers of mucus plugs resulted in higher mucus plug scores. RESULTS: Absolute change from baseline (mean [±standard deviation]) in mucus plug score was −1.7±2.6 in patients receiving tezepelumab (n=37) and 0.0±1.4 in patients receiving placebo (n=45). At baseline, mucus plug scores correlated positively with levels of inflammatory biomarkers (blood eosinophils, eosinophil-derived neurotoxin, fractional exhaled nitric oxide, IL-5, and IL-13) and negatively with lung function measures (prebronchodilator forced expiratory volume in 1 second and forced mid-expiratory flow). In tezepelumab recipients, reductions in mucus plug scores were correlated with improvements in lung function and reductions in blood eosinophil count and levels of eosinophil-derived neurotoxin, a biomarker of eosinophilic degranulation. CONCLUSIONS: Tezepelumab was associated with a reduction in occlusive mucus plugs versus placebo in a randomized controlled trial in patients with moderate-to-severe, uncontrolled asthma. (Funded by AstraZeneca and Amgen Inc.; ClinicalTrials.gov number, NCT03688074.)

Personalized Medicine in Asthma: Current Approach and Future Perspectives

Asthma is one of the most common chronic respiratory diseases, affecting over 300 million people worldwide [...].

Longitudinal Lung Function Assessment of Patients Hospitalized With COVID-19 Using 1H and 129Xe Lung MRI

BACKGROUND

Microvascular abnormalities and impaired gas transfer have been observed in patients with COVID-19. The progression of pulmonary changes in these patients remains unclear.

RESEARCH QUESTION

Do patients hospitalized with COVID-19 without evidence of architectural distortion on structural imaging exhibit longitudinal improvements in lung function measured by using 1H and 129Xe MRI between 6 and 52 weeks following hospitalization?

STUDY DESIGN AND METHODS

Patients who were hospitalized with COVID-19 pneumonia underwent a pulmonary 1H and 129Xe MRI protocol at 6, 12, 25, and 51 weeks following hospital admission in a prospective cohort study between November 2020 and February 2022. The imaging protocol was as follows: 1H ultra-short echo time, contrast-enhanced lung perfusion, 129Xe ventilation, 129Xe diffusion-weighted, and 129Xe spectroscopic imaging of gas exchange.

RESULTS

Nine patients were recruited (age 57 ± 14 [median ± interquartile range] years; six of nine patients were male). Patients underwent MRI at 6 (n = 9), 12 (n = 9), 25 (n = 6), and 51 (n = 8) weeks following hospital admission. Patients with signs of interstitial lung damage were excluded. At 6 weeks, patients exhibited impaired 129Xe gas transfer (RBC to membrane fraction), but lung microstructure was not increased (apparent diffusion coefficient and mean acinar airway dimensions). Minor ventilation abnormalities present in four patients were largely resolved in the 6- to 25-week period. At 12 weeks, all patients with lung perfusion data (n = 6) showed an increase in both pulmonary blood volume and flow compared with 6 weeks, although this was not statistically significant. At 12 weeks, significant improvements in 129Xe gas transfer were observed compared with 6-week examinations; however, 129Xe gas transfer remained abnormally low at weeks 12, 25, and 51.

INTERPRETATION

129Xe gas transfer was impaired up to 1 year following hospitalization in patients who were hospitalized with COVID-19 pneumonia, without evidence of architectural distortion on structural imaging, whereas lung ventilation was normal at 52 weeks.