Characterization of T2-Low and T2-High Asthma Phenotypes in Real-Life

Interleukin-33 modulates NET formation via an autophagy-dependent manner to promote neutrophilic inflammation in cigarette smoke-exposure asthma

Cigarette smoke (CS) contributes to IL---33 release and neutrophil inflammation in asthma. Neutrophil extracellular traps (NETs) are essential for neutrophil function. However, the effect of IL--33 on neutrophils in cigarette smoke--exposure asthma remains unclear. We found that CS exposure led to lower lung function and a neutrophil--related phenotype in asthma, characterized by elevated neutrophil and Th17 cell counts. Granulocytic airway inflammation was ablated by sST2, which blocked excessive IL--33 release. Transcriptome analysis of mouse lungs revealed that IL--33 enhanced NET formation in HDM/CS-treated mice, which was further confirmed in our experimental asthma model and in asthma patients. NETs were associated with poor lung function and airway inflammation and directly facilitated monocyte--derived dendritic cell activation, further inducing Th2/Th17 polarization. Furthermore, we demonstrated a feedforward loop between NETs and neutrophil autophagy, both of which are dependent on reactive oxygen species (ROS) production and the mTOR-Hif-1α signaling pathway. Notably, IL--33 knockout suppressed autophagy and NETs, whereas the autophagy agonist rapamycin reversed the inhibition of NETs by sST2 in a mTOR--dependent manner. Our findings revealed that the IL--33/ST2 signaling pathway interacts with the neutrophil -autophagy--mTOR-Hif-1α-NET pathway, ultimately aggravating Th2/Th17-related inflammation. These insights could lead to potential therapeutic targets for mitigating exacerbations in asthmatic patients who are exposed to CS.

A real-world study on tezepelumab effectiveness in severe asthma focusing on small airway dysfunction

BACKGROUND

Severe asthma (SA) is a complex condition often involving small airway dysfunction (SAD). Tezepelumab has demonstrated efficacy in clinical trials, but real-world evidence is scarce, and its impact on SAD remains unexplored.

OBJECTIVE

This prospective study evaluated the effectiveness of tezepelumab in patients with SA, stratified by the SAD presence and asthma phenotype (type 2-high vs type 2-low).

METHODS

Seventeen SA patients received tezepelumab. A range of clinical and laboratory outcomes were assessed, including annualized asthma exacerbation rate (AAER), lung function, and oral corticosteroids (OCS) use. Respiratory parameters were assessed using spirometry, body plethysmography, and forced oscillation technique (FOT).

RESULTS

After 6 months of treatment, tezepelumab significantly reduced median AAER (from 5.0 to 0.0, p = 0.001) and OCS dose (from 14.6 mg/day to 0.0 mg/day, p < 0.001), alongside a marked reduction in median blood eosinophil count (from 130 to 60 cells/mm3, p = 0.032). Among respiratory parameters, total resistance, measured by body plethysmography, improved significantly in the overall population (median values from 0.49 to 0.37 KPa L s-1, p = 0.005). Spirometry and FOT measures, including total reactance (p = 0.018) and tidal expiratory flow limitation (p = 0.043), improved only in patients with SAD.

CONCLUSION

Tezepelumab significantly reduced exacerbations and improved asthma control, positively impacting respiratory parameters and small airway function in patients with SAD. These findings support SAD as a treatable trait, highlighting the importance of integrating advanced diagnostic tools, such as body plethysmography and FOT, into routine clinical practice.

Dog allergen-induced asthma in mice: a relevant model of T2low severe asthma with airway remodelling

OBJECTIVE AND DESIGN

Airway remodelling (AR) is a disabling phenomenon in patients with severe asthma, yet suitable models are lacking. We previously developed a dog allergen-induced murine asthma model characterized by T2low Th17-driven neutrophilic airway inflammation and AR. To assess its relevance to human AR associated with T2low severe asthma, a condition characterised by poor response to inhaled steroids, we tested the steroid sensitivity of the key features of this model.

MATERIAL

Asthma was induced in C57BL/6 J mice by intranasal sensitization, followed by a three-week challenge with dog allergen.

TREATMENT

Daily intraperitoneal 1 mg kg-1 dexamethasone was administrated during the last week of challenge.

METHODS

We measured airway resistances in response to methacholine, cellular inflammation in bronchoalveolar lavage, lung cytokines, and quantified AR features, in response to dexamethasone.

RESULTS

Dexamethasone-treated mice showed persistent airway hyperresponsiveness, neutrophilic inflammation, and Il17a overexpression, whereas Il22 expression was abrogated. Pathological AR features, including mucus hyperproduction, subepithelial fibrosis and smooth muscle hypertrophy were not eliminated by dexamethasone.

CONCLUSIONS

Our dog allergen-induced murine model of asthma mirrors the steroid-insensitive traits of human severe T2low asthma with AR, making it a relevant tool for identifying novel therapeutic targets in this orphan asthma subset.

Natural killer cells in the lung: novel insight and future challenge in the airway diseases

Natural killer (NK) cells are innate lymphoid cells which are present in the lung as circulating and resident cells. They are key players both in airway surveillance and in crosstalk with (COPD) pathogenesis, and they seem to contribute to the development of bronchiectasis. In asthma, NK cell dysfunction was observed mainly in severe forms, and it can lead to a biased type-2 immune response and failure in the resolution of eosinophilic inflammation that characterise both allergic and eosinophilic phenotypes. Moreover, aberrant NK cell functions may interfere with antimicrobial immune response contributing to the frequency and severity of virus-induced exacerbations. In COPD, lung NK cells exhibit increased cytotoxicity against lung epithelium contributing to lung tissue destruction and emphysema. This cell destruction may be exacerbated by viral infections and cigarette smoke exposure through NKG2D-dependent detection of cellular stress. Lastly, in bronchiectasis, the airway NK cells might both promote neutrophil survival following stimulation by proinflammatory cytokines and promote neutrophil apoptosis. Systemic steroid treatment seemingly compromises NK activity, while biologic treatment with benralizumab could enhance NK cell proliferation, maturation and activation. This narrative review gives an overview of NK cells in airway diseases focusing on pathophysiological and clinical implications. Together, our findings emphasise the pleiotropic role of NK cells in airway diseases underscoring their possible implications as to therapeutical approaches.

Eosinophil-Driven vs. Eosinophil-Associated Severe Asthma: Practical Implications for Target Treatment

Severe asthma (SA) is a chronic inflammatory condition affecting approximately 10% of asthmatic patients, and eosinophils are considered key pathogenetic actors in a significant number of patients. Biological therapies have been demonstrated to improve asthma control by decreasing exacerbation rates and reducing the use of oral corticosteroids. In this context, phenotyping and endotyping patients with SA is essential for selecting the most effective therapeutic approach. For this purpose, biomarkers such as IgE, absolute blood eosinophil count, and fractional exhaled nitric oxide (FeNO) are crucial in defining a patient's inflammatory profile. Their integration provides a framework for classifying asthma into T2-high, T2-mild, or T2-low categories, guiding personalized treatment strategies. By incorporating multiple biomarkers into a unified model, it is possible to better stratify patients and optimize biologic therapy selection, paving the way for improved outcomes in SA management. This review aims to evaluate the role of phenotyping and endotyping SA patients, with particular attention to the impact of eosinophilic inflammation and combinatory biomarkers on decision-making processes for the selection of biological therapies.

T2-low severe asthma clinical spectrum and impact: The Greek PHOLLOW cross-sectional study

BACKGROUND

Data on type 2 (T2)-low severe asthma (SA) frequency is scarce, resulting in an undefined unmet therapeutic need in this patient population. Our objective was to assess the frequency and characterize the profile and burden of T2-low SA in Greece.

METHODS

PHOLLOW was a cross-sectional study of adult SA patients. Based on a novel proposed classification system, patients were classified as T2-low if blood eosinophil count (BEC; cells/μL) was <150, fractional exhaled nitric oxide (FeNO) < 25 ppb and any allergy status or BEC < 150/FeNO < 50 ppb/no allergy or BEC < 300/FeNO < 25 ppb/no allergy. For patients receiving biologics and/or oral corticosteroids, only those with BEC < 150/FeNO < 25 ppb/no allergy/no response to therapy were classified as T2-low. Secondary outcome measures were: Asthma Control Test (ACTTM), Mini-Asthma Quality of Life Questionnaire (Mini-AQLQ), hospital anxiety and depression scale (HADS), and Work Productivity and Activity Impairment:Respiratory Symptoms (WPAI:RS) questionnaire.

RESULTS

From 22-Mar-2022 to 15-Mar-2023, 602 eligible SA patients were enrolled. The frequency of T2-low asthma was 20.1%. Of those, 71.1% had experienced ≥1 clinically significant exacerbations in the past year, 62.8% had ACT score <20 (uncontrolled asthma), and 22.3% were biologic-treated. Mini-AQLQ score was <6 (impairment) in 79.5% of patients, HADS-total score was ≥15 (clinically significant emotional distress) in 43.8%, while median percent activity impairment and work productivity loss were 30.0 for both domains. Clinical and patient-reported outcomes were worse among patients with ACT-defined uncontrolled asthma.

CONCLUSIONS

One-fifth of SA patients present with a T2-low endotype. These patients frequently have uncontrolled disease and experience impairments in their quality of life, emotions and work ability.

A Multifaceted Exploration of Status Asthmaticus: A Retrospective Analysis in a Romanian Hospital

Background: Status asthmaticus is a severe, life-threatening asthma exacerbation requiring urgent medical intervention. This study aims to examine its epidemiology in Timis County, Romania, over 11 years. Methods: A retrospective analysis was conducted using hospital records from 2013 to 2023, focusing on demographic, geospatial, and temporal distributions. Network analysis of the recorded comorbidities was used to identify phenotypic clusters among patients. Results: Females and older adults were disproportionately affected. Several triggers and geospatial patterns were identified. Five phenotypic clusters were determined: two in the T2-high endotype, two in T2-low, and a mixed one. Conclusions: The findings highlight the need for personalized asthma management strategies and public healthcare interventions in Timiș County, addressing specific demographic and geospatial factors. This study also provides a valuable reference for similar regions.

An interpretable cluster-based logistic regression model, with application to the characterization of response to therapy in severe eosinophilic asthma

Asthma is a disease characterized by chronic airway hyperresponsiveness and inflammation, with signs of variable airflow limitation and impaired lung function leading to respiratory symptoms such as shortness of breath, chest tightness and cough. Eosinophilic asthma is a distinct phenotype that affects more than half of patients diagnosed with severe asthma. It can be effectively treated with monoclonal antibodies targeting specific immunological signaling pathways that fuel the inflammation underlying the disease, particularly Interleukin-5 (IL-5), a cytokine that plays a crucial role in asthma. In this study, we propose a data analysis pipeline aimed at identifying subphenotypes of severe eosinophilic asthma in relation to response to therapy at follow-up, which could have great potential for use in routine clinical practice. Once an optimal partition of patients into subphenotypes has been determined, the labels indicating the group to which each patient has been assigned are used in a novel way. For each input variable in a specialized logistic regression model, a clusterwise effect on response to therapy is determined by an appropriate interaction term between the input variable under consideration and the cluster label. We show that the clusterwise odds ratios can be meaningfully interpreted conditional on the cluster label. In this way, we can define an effect measure for the response variable for each input variable in each of the groups identified by the clustering algorithm, which is not possible in standard logistic regression because the effect of the reference class is aliased with the overall intercept. The interpretability of the model is enforced by promoting sparsity, a goal achieved by learning interactions in a hierarchical manner using a special group-Lasso technique. In addition, valid expressions are provided for computing odds ratios in the unusual parameterization used by the sparsity-promoting algorithm. We show how to apply the proposed data analysis pipeline to the problem of sub-phenotyping asthma patients also in terms of quality of response to therapy with monoclonal antibodies.

House dust mite allergen directly activates ILC2 cells via the TLR4 signaling pathway in allergic airway diseases

BACKGROUND

Unlike T cells and B cells, the activation process of group 2 innate lymphoid cells (ILC2s) is mainly driven by epithelial cell derived cytokines rather than specific antigen recognition. Whether antigens have a direct role in activating ILC2s remains poorly understood.

METHODS

Following stimulation, type 2 cytokine secretions and cell death were assessed in house dust mite (HDM)-stimulated ILC2s. To investigate the underlying mechanisms, RNA-sequencing (RNA-seq) was performed on HDM-stimulated ILC2s. The validation experiments were done through in vitro stimulation assays and an HDM-induced asthmatic murine model, using specific inhibitors targeting receptor and relevant proteins of signaling pathways.

RESULTS

HDM stimulation increased the secretion of IL-5 and IL-13 cytokines from ILC2s, inhibited apoptosis of ILC2, and promoted the proliferation of ILC2s. As confirmed by RNA-seq, HDM stimulation upregulated genes in ILC2s, including those responsible for type 2 cytokines, ILC2s-specific transcriptional factors, and related receptors. Both toll-like receptor (TLR) 1 and TLR4 were constitutively expressed on ILC2s, however, only TLR4 was predominantly upregulated upon HDM stimulation. TAK242, a specific TLR4 inhibitor, significantly blocked the effect of HDM on ILC2s, in terms of type 2 cytokine secretions and cell death. Using specific inhibitors in pathways, we confirmed that HDM promoted ILC2s activation via TLR4-ERK, p38, and NF-κB signaling pathways.

CONCLUSIONS

Allergen HDM directly activates ILC2s through TLR4 mediated-ERK/p38/NF-κB signaling pathway. These findings provide new insights into how antigens propagate type 2 immune response via ILC2s, contributing to chronic inflammations in allergic airway diseases.

Asthma and hypertension: the role of airway inflammation

Introduction

Asthma is a chronic inflammatory respiratory disease often associated with comorbidities. Among cardiovascular comorbidities, arterial hypertension seems to create an additional health burden in asthmatics. However, evidence on this relationship is lacking.

Objective

Our study aims to evaluate the characteristics of hypertensive asthmatics, focusing on the role of inflammation as a possible link between these diseases.

Methods

We conducted a monocentric retrospective analysis consecutively including asthmatics who underwent induced sputum (IS) at our asthma referral center. Patients were divided in two groups according to presence or absence of history of hypertension. Clinical, functional, and inflammatory (airway and systemic) data were collected.

Results

Data on two hundred and sixty asthmatic patients were analyzed. Seventy-nine (30.4%) of them had a diagnosis of hypertension requiring a specific pharmacological treatment. Asthmatics with hypertension were more frequently male (p = 0.047), older (p < 0.001), and with higher body max index (BMI) (p < 0.001) when compared to normotensive patients. No difference concerning asthma control, severity and pharmacological treatment was observed between the two groups (all p > 0.05); distribution of comorbidities and lung function impairment (forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC); all p < 0.05) were statistically different between groups. Mixed granulocytic airway inflammation was prevalent in the hypertensive asthmatics (p = 0.014). Interestingly, a multivariable analysis revealed that age ≥ 65 years and an increased percentage of sputum neutrophils (≥61%) were independent predictors of hypertensive status (p < 0.001).

Conclusion

Our data suggest that neutrophilic airway inflammation (as evaluated by induced sputum) is strictly associated with hypertension. In clinical practice, phenotyping asthmatic patients with comorbidities like hypertension could be useful also from a therapeutic point of view. Additional studies are mandatory to further elucidate the role of neutrophilic airway inflammation in asthma with cardiovascular diseases.

Bioinformatics analysis of G protein subunit gamma transduction protein 2-autophagy axis in CD11b+ dendritic cells as a potential regulator to skew airway neutrophilic inflammation in asthma endotypes

BACKGROUND

Asthma is a heterogeneous inflammatory disease with two main clinical endotypes: type 2 (T2) high and low asthma. The plasticity and autophagy in dendritic cells (DCs) influence T helper (Th)2 or Th17 differentiation to regulate asthma endotypes. Enhanced autophagy in DCs fosters Th2 differentiation in allergic environments, while reduced autophagy favors Th17 cell differentiation in sensitized and infected environments. Autophagy regulation in DCs involves interaction with various pathways like G protein-coupled receptor (GPCR), mammalian target of rapamycin (mTOR), or phosphoinositide 3-kinase (PI3K) pathway. However, specific molecules within DCs influencing asthma endotypes remain unclear.

METHODS

Gene expression data series (GSE) 64896, 6858, 2276, and 55247 were obtained from gene expression omnibus (GEO) database. Differentially expressed genes (DEGs) between CD103+ and CD11b+ DCs after induction by ovalbumin (OVA) and lipopolysaccharide (LPS) were analyzed using GEO2R. DEGs were examined through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) analyses. The hub gene network was construct with STRING database and Cytoscape. Autophagy differences in DCs and the selected hub gene in GSE6858, GSE2276, and GSE55247 were evaluated using student t tests.

RESULTS

Our analysis identified 635 upregulated and 360 downregulated genes in CD11b+ DCs, compared to CD103+ DCs. These DEGs were associated with "PI3K-AKT signaling pathway," "Ras signaling pathway," and so forth. Thirty-five hub genes were identified, in which G protein subunit gamma transduction protein 2 (Gngt2) in CD11b+ DCs exhibited a relatively specific increase in expression associated with autophagy defects under the induction environment similar to T2 low asthma model. No significant difference was found in lung Gngt2 expression between T2 high asthma model and control group.

CONCLUSION

Our analysis suggested Gngt2 acted as an adapter molecule that inhibited autophagy, promoting Th17-mediated airway inflammation via the GPCR pathway in a T2 low asthma mice model. Targeting this pathway provides new asthma treatment strategies in preclinical research.

Real-World Data on Tezepelumab in Patients With Severe Asthma in Germany

BACKGROUND

Tezepelumab is a novel biologic blocking thymic stromal lymphopoetin, approved for severe asthma irrespective of biomarker levels or phenotype.

OBJECTIVE

To characterize a real-world tezepelumab patient cohort and the efficacy among various asthma phenotypes.

METHODS

We performed a retrospective, multicenter study on patients with severe asthma initiating tezepelumab. Clinical response was evaluated at 3 and 6 months.

RESULTS

We included 129 patients with an average age of 52.5 ± 13.1 years, 59.7% were female. The majority (86.0%) had increased type 2 (T2) biomarkers, 68.2% an allergic and 31.8% an eosinophilic phenotype. 23.3% of patients were biologic-naive. 22 (18.2%) patients discontinued tezepelumab therapy owing to suspected side effects or insufficient efficacy. At 6 months' follow-up, median reduction in annualized exacerbation rate was-1 [25th percentile; 75% percentile {-2.9; 0.0}], the reduction of oral corticosteroid dose among patients with long-term oral corticosteroid therapy was -5 mg [-10; 0] and the Asthma Control Test (ACT) improved by 2 [0; 5] points. A treatment response according to Biologic Asthma Response Score of 80.8% was demonstrated. There were no significant differences in treatment response between T2-high versus T2-low, early- versus adult-onset and eosinophilic versus non-eosinophilic asthma. Prior treatment with other biologics was associated with inferior treatment response.

CONCLUSIONS

In this real-life cohort, including a large proportion of patients with history of previous biologic use and encompassing various subgroups, the majority responded to tezepelumab. Our data further suggest a steroid-sparing effect of tezepelumab.

Biologics in T2 Severe Asthma: Unveiling Different Effectiveness by Real-World Indirect Comparison

Background: Indirect comparison among biologics in severe asthma (SA) is a challenging but desirable goal for clinicians in real life. The aim of the study is to define characteristics of a biologic-treated T2-driven-SA population and to evaluate the effectiveness of biologic treatments in a real-world setting by variation in intra/inter-biologic parameters in an up to 4-year follow-up. Methods: Demographic, clinical, functional, and biological characteristics were evaluated retrospectively in 104 patients recruited until July 2022 at baseline (T0) and over a maximum of 4 years (T4) of biologic therapy (omalizumab/OmaG = 41, from T0 to T4, mepolizumab/MepoG = 26, from T0 to T4, benralizumab/BenraG = 18, from T0 to T2, and dupilumab/DupiG = 19, from T0 to T1). Variations of parameters using means of paired Delta were assessed. Results: At baseline, patients had high prevalence of T2-driven comorbidities, low asthma control test (ACT mean 17.65 ± 4.41), impaired pulmonary function (FEV1 65 ± 18 %pred), frequent exacerbations/year (AEs 3.5 ± 3), and OCS dependence (60%). DupiG had lower T2 biomarkers/comorbidities and AEs, and worse FEV1 (57 ± 19 %pred) compared to other biologics (p < 0.05). All biologics improved ACT, FEV1%, FVC%, AEs rate, and OCS use. FEV1% improved in MepoG and BenraG over the minimal clinically important difference and was sustained over 4 years in OmaG and MepoG. A significant RV reduction in OmaG (T4) and DupiG (T1), and BenraG normalization (T2) of airflow limitation were found. We observed through inter-biologic parameters pair delta variation comparison a significant nocturnal awakenings reduction in BenraG vs. OmaG/MepoG, and neutrophils reduction in BenraG/DupiG vs. OmaG. Conclusions: Indirect comparison among biologics unveils clinical and functional improvements that may mark a different effectiveness. These results may highlight the preference of a single biologic compared to another with regard to specific treatable traits.

Frequency of Severe Asthma and Its Clinical Phenotypes at the Asthma Clinic in One of the Largest Sudanese Tertiary Pediatric Hospitals: A Cross-Sectional Hospital-Outpatient-Based Study

Background

Asthma is one of the most common non-communicable diseases. Childhood asthma has been increasing in Sudan, with a 13-16% prevalence among Khartoum school children. To achieve and maintain good asthma control, proper diagnosis, assessment of severity, and appropriate medication administration are crucial, with phenotyping being a key factor in determining patients' specific treatment.

Objective

To study the frequency of severe asthma and the distribution of its different phenotypes and to investigate associations between age and gender and different phenotypes of asthma.

Methodology

This descriptive cross-sectional hospital-based study was conducted in the Asthma Clinic of Mohamed Al-Amin Hamid Pediatrics Hospital. It included 229 patients who were presented to the clinic from September 2021 to April 2022. Data were collected from the patients and/or their caregivers using a modified validated standard questionnaire and were analyzed using SPSS version 26.0. A p-value of 0.05 or less was considered statistically significant.

Results

In this study of 229 participants, 14.4% had severe asthma, with 44.5% and 41% exhibiting mild and moderate asthma, respectively. Most were effectively managed in steps 2 or 3. The cohort, primarily aged 5 or younger (40.2%) with a male majority (62%), showed a mean diagnosis age of 2.9 ± 2.8 years. Impressively, 90% maintained well-controlled asthma. Within severe asthma cases (87% atopic), 39.4% represented a severe allergic asthma phenotype. Elevated eosinophil counts were noted in 45.5% (serum) and 78.8% (sputum cytology), while 57.6% had normal serum IgE levels. The predominant symptom pattern in severe asthma was episodic multi-trigger wheezing (48.5%). Age and gender displayed no significant association with severe asthma phenotype.

Conclusion

This study reveals a concerning rise in childhood asthma prevalence in Sudan, emphasizing the importance of tailored treatment strategies. Severe asthma, characterized by atopic eosinophilic involvement, necessitates targeted interventions in pediatric asthma care for specific phenotypes.

Endotyping Chronic Respiratory Diseases: T2 Inflammation in the United Airways Model

Over the past 15 years, the paradigm of viewing the upper and lower airways as a unified system has progressively shifted the approach to chronic respiratory diseases (CRDs). As the global prevalence of CRDs continues to increase, it becomes evident that acknowledging the presence of airway pathology as an integrated entity could profoundly impact healthcare resource allocation and guide the implementation of pharmacological and rehabilitation strategies. In the era of precision medicine, endotyping has emerged as another novel approach to CRDs, whereby pathologies are categorized into distinct subtypes based on specific molecular mechanisms. This has contributed to the growing acknowledgment of a group of conditions that, in both the upper and lower airways, share a common type 2 (T2) inflammatory signature. These diverse pathologies, ranging from allergic rhinitis to severe asthma, frequently coexist and share diagnostic and prognostic biomarkers, as well as therapeutic strategies targeting common molecular pathways. Thus, T2 inflammation may serve as a unifying endotypic trait for the upper and lower airways, reinforcing the practical significance of the united airways model. This review aims to summarize the literature on the role of T2 inflammation in major CRDs, emphasizing the value of common biomarkers and integrated treatment strategies targeting shared molecular mechanisms.

Real-World Evaluation of Asthma Severity Following Endoscopic Sinus Surgery in Chronic Rhinosinusitis Patients

Objective

This study aimed to evaluate the impact of endoscopic sinus surgery (ESS) on asthma severity up to 12 months after surgical intervention.

Study Design

Retrospective cohort.

Setting

Tertiary care center.

Methods

Patients with a history of asthma and Chronic Rhinosinusitis (CRS) who underwent ESS between 2013 and 2023 were included. Asthma severity was assessed according to current Global Initiative for Asthma (GINA) guidelines, classifying patients into mild, moderate, and severe based on medication requirements. Asthma severity was evaluated up to 3 months prior to ESS and 1-year post-ESS. Patients with aspirin-exacerbated respiratory disease (AERD) were excluded. Statistical analysis was performed using McNemar test and Wilcoxon signed-rank test to assess differences in asthma severity, medication doses, and number of medications.

Results

Sixty-five patients were included, of which 44 (67.7%) had CRS with nasal polyps (CRSwNP) and 21 (32.3%) had CRS without nasal polyps (CRSsNP). No significant differences were found in asthma severity pre- and post-ESS (P = .175). Similarly, no differences were found in ICS doses (P = .999), total number of prescribed medications (P = .157) or presence of exacerbations before and after ESS (P = .078). However, a significant increase in time from last rescue inhaler use was noted after ESS, increasing from a median of 6.71 to 23.1 weeks (P = .004).

Conclusion

This study is the first to assess the impact of ESS on asthma severity in a real-world setting. Our findings suggest that ESS does not impact asthma severity classification. However, it might provide relief of asthma symptoms in the early postoperative period.

Baseline Characteristics and ICS/LAMA/LABA Response in Asthma: Analyses From the CAPTAIN Study

BACKGROUND

Findings from CAPTAIN (NCT02924688) suggest that treatment response to fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) differs according to baseline type 2 inflammation markers in patients with moderate to severe asthma. Understanding how other patient physiologic and clinical characteristics affect response to inhaled therapies may guide physicians toward a personalized approach for asthma management.

OBJECTIVE

To investigate, using CAPTAIN data, the predictive value of key demographic and baseline physiologic variables in patients with asthma (lung function, bronchodilator reversibility, age, age at asthma onset) on response to addition of the long-acting muscarinic antagonist UMEC to inhaled corticosteroid/long-acting β2-agonist combination FF/VI, or doubling the FF dose.

METHODS

Prespecified and post hoc analyses of CAPTAIN data were performed using categorical and continuous variables of key baseline characteristics to understand their influence on treatment outcomes (lung function [trough FEV1], annualized rate of moderate/severe exacerbations, and asthma control [Asthma Control Questionnaire]) following addition of UMEC to FF/VI or doubling the FF dose in FF/VI or FF/UMEC/VI.

RESULTS

Adding UMEC to FF/VI led to greater improvements in trough FEV1 versus doubling the FF dose across all baseline characteristics assessed. Doubling the FF dose was generally associated with numerically greater reductions in the annualized rate of moderate/severe exacerbations compared with adding UMEC, independent of baseline characteristics. Adding UMEC and/or doubling the FF dose generally led to improvements in Asthma Control Questionnaire scores irrespective of baseline characteristics.

CONCLUSIONS

Unlike previous findings with type 2 biomarkers, lung function, bronchodilator reversibility, age and age at asthma onset do not appear to predict response to inhaled therapy.

ERS International Congress 2023: highlights from the Airway Diseases Assembly

In this review, early career and senior members of Assembly 5 (Airway Diseases, Asthma, COPD and Chronic Cough) present key recent findings pertinent to airway diseases that were presented during the European Respiratory Society International Congress 2023 in Milan, Italy, with a particular focus on asthma, COPD, chronic cough and bronchiectasis. During the congress, an increased number of symposia, workshops and abstract presentations were organised. In total, 739 abstracts were submitted for Assembly 5 and the majority of these were presented by early career members. These data highlight the increased interest in this group of respiratory diseases.

Tropical high altitude and severe asthma in adults: house dust mite sensitization and phenotypic distribution

BACKGROUND

There is a lack of information on house dust mite (HDM) sensitization and phenotype distribution in patients with severe asthma (SA) living permanently at high-altitude (HA) in tropical regions, which may be different.

OBJECTIVE

The aim of this study was to characterize adults with SA in a tropical high altitude city (2,640 m): Bogotá, Colombia.

MATERIAL AND METHODS

This observational cross-sectional study included severe asthmatic outpatients (n = 129) referred to the ASMAIRE program of the Fundación Neumológica Colombiana in Bogotá (2,640 m). Clinical history, spirometry, total IgE, blood eosinophils, and skin prick test (SPT), including HDM allergens, were performed. Phenotype definitions: Allergic/atopic (AA): IgE ≥100 IU/mL and/or at least one positive SPT; eosinophilic (EOS): blood eosinophils ≥300 cells/µL; type 2-high: AA and/or EOS phenotype; type 2-low: non-AA/non-EOS phenotype (IgE <100 IU/mL, negative SPT, and blood eosinophils <300 cells/µL).

RESULTS

A total of 129 adults with SA were included, 79.8% female. Phenotype distribution: AA: 61.2%; EOS: 37.2%; type 2-high: 72.1%; type 2-low: 27.9%. Among AA patients, HDM sensitization was present in 87% and 34.9% were non-eosinophilic. There was a significant overlap between the phenotypes.

CONCLUSIONS

In contrast to non-tropical high-altitude regions, we found a high frequency of HDM sensitization in patients with AA phenotype living in a tropical high-altitude city. We also found a discrete lower frequency of EOS phenotype with no other significant differences in the phenotypic distribution compared to that described at low altitudes. We propose that tropical location may modify the effect of high altitude on HDM concentrations and allergenicity.

Genetic relationships between high blood eosinophil count, asthma susceptibility, and asthma severity

OBJECTIVE

Genetic relationships between blood eosinophil count (BEC), asthma susceptibility, and severity are unclear. We sought to identify the genetic difference between type 2 (T2) and nontype 2 (non-T2) asthma (defined by BEC) and investigate genetic relationships between high BEC, asthma susceptibility, and severity.

METHODS

Genome-wide association studies (GWASs) were performed for T2 (n = 9,064; BEC ≥ 300 cells/μL) versus non-T2 asthma (n = 14,379; BEC < 150 cells/μL) and asthma susceptibility (37,227 asthmatics vs. 124,132 nonasthma controls) in the UK Biobank and asthma severity (moderate-to-severe asthma [n = 2,153] vs. mild asthma [n = 5165]) in the All of Us Research Program (AoURP). Genetic causality between BEC, asthma susceptibility, and severity were dissected using Mendelian randomization (MR).

RESULTS

High BEC was associated with asthma and decreased pulmonary function. GWASs revealed four sets of genetic variants (p < 5 × 10-8): genes associated with only BEC or asthma and genes associated with high BEC and asthma in the same or opposite direction. The C allele of rs653178 in ATXN2 was associated with high BEC, risk for autoimmune diseases, and protection for asthma. Genetic variants associated with BEC or asthma were not associated with asthma severity. MR indicated high BEC and asthma were in bidirectional causal relationship (p < .001); however, they were not causal for asthma severity.

CONCLUSIONS

Genetic variants associated with asthma or BEC and asthma severity are distinctive. High BEC is a risk factor for asthma; however, it is neither necessary nor sufficient for asthma susceptibility and severity.

Effects of biological therapies on patients with Type-2 high asthma and comorbid obesity

Over 20 million adults and 6 million children in the United States (US) have asthma, a chronic respiratory disease characterized by airway inflammation, bronchoconstriction, and mucus hypersecretion. Obesity, another highly prevalent disease in the US, is a major risk factor for asthma and a significant cause of diminished asthma control, increased submucosal eosinophilia, and reduced quality of life. A large subgroup of these patients experiences severe symptoms and recurrent exacerbations despite maximal dosage of standard asthma therapies. In the past two decades, the development of biological therapies has revolutionized the field and advanced our understanding of type 2 inflammatory biomarkers. However, patients with obesity and comorbid asthma are not principally considered in clinical trials of biologics. Large landmark cluster analyses of patients with asthma have consistently identified specific asthma phenotypes that associate with obesity but may be differentiated by age of asthma onset and inflammatory cell profiles in sputum. These patterns suggest that biologic processes driving asthma pathology are heterogenous among patients with obesity. The biological mechanisms driving pathology in patients with asthma and comorbid obesity are not well understood and likely multifactorial. Future research needs to be done to elicit the cellular and metabolic functions in the relationship of obesity and asthma to yield the best treatment options for this multiplex condition. In this review, we explore the key features of type 2 inflammation in asthma and discuss the effectiveness, safety profile, and research gaps regarding the currently approved biological therapies in asthma patients with obesity.

Tailored Biologics Selection in Severe Asthma

The management of severe asthma presents a significant challenge in asthma treatment. Over the past few decades, remarkable progress has been made in developing new treatments for severe asthma, primarily in the form of biological agents. These advances have been made possible through a deeper understanding of the underlying pathogenesis of asthma. Most biological agents focus on targeting specific inflammatory pathways known as type 2 inflammation. However, recent developments have introduced a new agent targeting upstream alarmin signaling pathways. This opens up new possibilities, and it is anticipated that additional therapeutic agents targeting various pathways will be developed in the future. Despite this recent progress, the mainstay of asthma treatment has long been inhalers. As a result, the guidelines for the appropriate use of biological agents are not yet firmly established. In this review, we aim to emphasize the current state of biological therapy for severe asthma and provide insights into its future prospects.

Lung epithelial cells: Upstream targets in type 2-high asthma

Over the last years, technological advances in the field of asthma have led to the identification of two disease endotypes, namely, type 2-high and type 2-low asthma, characterized by different pathophysiologic mechanisms at a cellular and molecular level. Although specific immune cells are important contributors to each of the recognized asthma endotype, the lung epithelium is now regarded as a crucial player able to orchestrate responses to inhaled environmental triggers such as allergens and microbes. The impact of the epithelium goes beyond its physical barrier. It is nowadays considered as a part of the innate immune system that can actively respond to insults. Activated epithelial cells, by producing a specific set of cytokines, trigger innate and adaptive immune cells to cause pathology. Here, we review how the epithelium contributes to the development of Th2 sensitization to allergens and asthma with a "type 2-high" signature, in both murine models and human studies of this asthma endotype. We also discuss epithelial responses to respiratory viruses, such as rhinovirus, respiratory syncytial virus, and SARS-CoV-2, and how these triggers influence not only asthma development but also asthma exacerbation. Finally, we also summarize the results of promising clinical trials using biologicals targeting epithelial-derived cytokines in asthmatic patients.

Parkin Promotes Airway Inflammatory Response to Interferon Gamma

PURPOSE

Increased type 2 interferon (i.e., IFN-γ) signaling has been shown to be involved in airway inflammation in a subset of asthma patients who often show high levels of airway neutrophilic inflammation and poor response to corticosteroid treatment. How IFN-γ mediates airway inflammation in a mitochondrial dysfunction setting (e.g., Parkin up-regulation) remains poorly understood. The goal of this study was to determine the role of Parkin, an E3 ubiquitin ligase, in IFN-γ-mediated airway inflammation and the regulation of Parkin by IFN-γ.

METHODS

A mouse model of IFN-γ treatment in wild-type and Parkin knockout mice, and cultured human primary airway epithelial cells with or without Parkin gene deficiency were used.

RESULTS

Parkin was found to be necessary for the production of neutrophil chemokines (i.e., LIX and IL-8) and airway neutrophilic inflammation following IFN-γ treatment. Mechanistically, Parkin was induced by IFN-γ treatment both in vivo and in vitro, which was associated with less expression of a Parkin transcriptional repressor Thap11. Overexpression of Thap11 inhibited Parkin expression in IFN-γ-stimulated airway epithelial cells.

CONCLUSIONS

Our data suggest a novel mechanism by which IFN-γ induces airway neutrophilic inflammation through the Thap11/Parkin axis. Inhibition of Parkin expression or activity may provide a new therapeutic target for the treatment of excessive neutrophilic inflammation in an IFN-γ-high environment.

Biomarker-guided withdrawal of inhaled corticosteroids in asthma patients with a non-T2 inflammatory phenotype - a randomized controlled trial study protocol

BACKGROUND

Non-T2 asthma is characterized by the absence of elevated type 2 inflammatory biomarkers such as blood-eosinophils, total and allergen-specific Immunoglobulin E and Fractional exhaled Nitric Oxide (FeNO). According to guidelines, inhaled corticosteroids (ICS) are the cornerstone of asthma management. However, ICS treatment is associated with a risk of local side effects, including hoarseness and thrush, and long-term high-dose therapy may cause systemic adverse effects. Furthermore, whereas treatment with ICS is highly effective in T2 asthma, studies have shown a markedly reduced ICS efficacy in patients with a lower degree of T2 inflammation, thus posing a clinical challenge in this subgroup of patients. Hence, owing to the ICS dosage step-up approach in current clinical guidelines, patients with low T2 biomarkers are at risk of being exposed to high doses of ICS, and by that at risk of side effects. Thus, an ICS-treatment regime guided by biomarkers that reflects the inflammatory phenotype is warranted in order to reduce the corticosteroid burden in patients with non-T2 asthma. This study combines a panel of non-T2 inflammatory markers (low periostin, low blood-eosinophils, and low FeNO), to determine if this group of patients can maintain asthma control during ICS withdrawal.

METHODS

This is an ongoing prospective multicenter open-label randomized, controlled trial aiming to assess if ICS can be safely tapered in patients with non-T2 asthma. The patients are randomized 1:1 to either standard of care or an ICS tapering regimen (n = 55 in each group) where the initial ICS dose is reduced by 50% for 8 weeks followed by total ICS removal. The primary endpoint is change in asthma control questionnaire (ACQ) from baseline to post-tapered ICS. The secondary endpoints are time from baseline to drop-out caused by loss of asthma control, changes in serum-periostin, blood-eosinophils, FeNO, Forced Expiratory Volume in 1 s (FEV1) and in sputum-eosinophils.

DISCUSSION

This study aims to provide data on ICS tapering in non-T2 asthma patients and to contribute to a more individualized and corticosteroid-sparing treatment regime in this group of patients.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03141424. Registration date: May 5th, 2017.

The effect of anti-IL5 monoclonal antibodies on regulatory and effector T cells in severe eosinophilic asthma

INTRODUCTION

Biological treatments have redesigned the clinical management of severe eosinophilic asthmatic (SA) patients. Despite emerging evidence supporting the role of natural Killer (NK), and T regulatory cells (Treg) in the pathogenesis of asthma, no data is available on the effects of anti-IL5/IL5R therapies on these cell subsets.

METHODS

We prospectively enrolled fourteen SA patients treated with benralizumab (n = 7) or mepolizumab (n = 7) and compared them with healthy controls (HC) (n = 11) and mild to moderate asthmatic (MM) patients (n = 9). Clinical parameters were collected at baseline (T0) and during follow-up. Cellular analysis, including the analysis of T/NK cell subsets, was determined through multicolor flow cytometry.

RESULTS

At T0, SA patients showed higher percentages of CD4 TEM (33.3 ± 17.9 HC, 42.6 ± 16.6 MM and 66.1 ± 19.7 in SA; p < 0.0001) than HC and MM patients. With different timing, the two drugs induce a reduction of CD4 TEM ( 76 ± 19 T0; 43 ± 14 T1; 45 ± 23 T6; 62 ± 18 at T24; p < 0.0001 for mepolizumab and 55 ± 21 T0; 55 ± 22 T1; 43 ± 14 T6; 27 ± 12 at T24; p < 0.0001 for benralizumab) and an increase of Treg cells (1.2 ± 1.3 T0; 5.1 ± 2.5 T1; 6.3 ± 3.4 T6; 8.4 ± 4.6 at T24; p < 0.0001 for mepolizumab and 3.4 ± 1.7 T0; 1.9 ± 0.8 T1; 1.9 ± 1 T6; 5.1 ± 2.4 at T24; p < 0.0001 for benralizumab). The change of CD56dim PD-1+ significantly correlated with FEV1% (r = - 0.32; p < 0.01), while Treg expressing PD-1 correlates with the use of oral steroids ( r = 0.36 p = 0.0008) and ACT score (r = 0.36 p = 0.0008) p < 0.001) CONCLUSIONS: Beyond the clinical improvement, anti-IL-5 treatment induces a rebalancing of Treg and T effector cells in patients with SA.

The Unified Airway Hypothesis: Evidence From Specific Intervention With Anti-IL-5 Biologic Therapy

The unified airway hypothesis proposes that upper and lower airway diseases reflect a single pathological process manifesting in different locations within the airway. Functional, epidemiological, and pathological evidence has supported this well-established hypothesis for some time. However, literature on the pathobiologic roles/therapeutic targeting of eosinophils and IL-5 in upper and lower airway diseases (including asthma, chronic rhinosinusitis with nasal polyps [CRSwNP], and nonsteroidal anti-inflammatory drug-exacerbated respiratory disease) has recently emerged. This narrative review revisits the unified airway hypothesis by searching the scientific literature for recent learnings and clinical trial/real-world data that provide a novel perspective on its relevance for clinicians. According to the available literature, eosinophils and IL-5 have important pathophysiological roles in both the upper and lower airways, although the impact of eosinophils and IL-5 may vary in asthma and CRSwNP. Some differential effects of anti-IL-5 and anti-IL-5-receptor therapies in CRSwNP have been observed, requiring further investigation. However, pharmaceutical targeting of eosinophils and IL-5 in patients with upper, lower, and comorbid upper and lower airway inflammation has led to clinical benefit, supporting the hypothesis that these are linked conditions manifesting in different locations. Consideration of this approach may improve patient care and aid clinical decision making.

Advances in the Relationship between Respiratory Viruses and Asthma

Several studies have reported that viral infection is closely associated with the onset, progression, and exacerbation of asthma. The purpose of this review is to summarize the role that viral infections have in the pathogenesis of asthma onset and exacerbations, as well as discuss interrelated protective and risk factors of asthma and current treatment options. Furthermore, we present current knowledge of the innate immunological pathways driving host defense, including changes in the epithelial barrier. In addition, we highlight the importance of the genetics and epigenetics of asthma and virus susceptibility. Moreover, the involvement of virus etiology from bronchiolitis and childhood wheezing to asthma is described. The characterization and mechanisms of action of the respiratory viruses most frequently related to asthma are mentioned.

Reliability of Total Serum IgE Levels to Define Type 2 High and Low Asthma Phenotypes

Background: High total IgE levels are weak predictors of T2High and have been reported in nonallergic asthma. Therefore, the role of total serum IgE (IgE) in the T2High phenotype is still debated. Objective: This study investigated the reliability of stratifying asthmatics into IgEHigh and IgELow within the T2High and T2Low phenotypes. Methods: This cross-sectional single-center study investigated the association of clinical, functional, and bio-humoral parameters in a large asthmatic population stratified by IgE ≥ 100 kU/L, allergen sensitization, B-EOS ≥ 300/µL, and FENO ≥ 30 ppb. Results: Combining T2 biomarkers and IgE identifies (1) T2Low-IgELow (15.5%); (2) T2Low-IgEHigh (5.1%); (3) T2High-IgELow (33.6%); and T2High-IgEHigh (45.7%). T2Low-IgELow patients have more frequent cardiovascular and metabolic comorbidities, a higher prevalence of emphysema, and higher LAMA use than the two T2High subgroups. Higher exacerbation rates, rhinitis, and anxiety/depression syndrome characterize the T2Low-IgEHigh phenotype vs. the T2Low-IgELow phenotype. Within the T2High, low IgE was associated with female sex, obesity, and anxiety/depression. Conclusions: High IgE in T2Low patients is associated with a peculiar clinical phenotype, similar to T2High in terms of disease severity and nasal comorbidities, while retaining the T2Low features. IgE may represent an additional biomarker for clustering asthma in both T2High and T2Low phenotypes rather than a predictor of T2High asthma "per se".

Inhaled drug delivery for the targeted treatment of asthma

Asthma is a chronic lung disease affecting millions worldwide. While classically acknowledged to result from allergen-driven type 2 inflammatory responses leading to IgE and cytokine production and the influx of immune cells such as mast cells and eosinophils, the wide range in asthmatic pathobiological subtypes lead to highly variable responses to anti-inflammatory therapies. Thus, there is a need to develop patient-specific therapies capable of addressing the full spectrum of asthmatic lung disease. Moreover, delivery of targeted treatments for asthma directly to the lung may help to maximize therapeutic benefit, but challenges remain in design of effective formulations for the inhaled route. In this review, we discuss the current understanding of asthmatic disease progression as well as genetic and epigenetic disease modifiers associated with asthma severity and exacerbation of disease. We also overview the limitations of clinically available treatments for asthma and discuss pre-clinical models of asthma used to evaluate new therapies. Based on the shortcomings of existing treatments, we highlight recent advances and new approaches to treat asthma via inhalation for monoclonal antibody delivery, mucolytic therapy to target airway mucus hypersecretion and gene therapies to address underlying drivers of disease. Finally, we conclude with discussion on the prospects for an inhaled vaccine to prevent asthma.

Phenotype overlap in the natural history of asthma

The heterogeneity of asthma makes it challenging to unravel the pathophysiologic mechanisms of the disease. Despite the wealth of research identifying diverse phenotypes, many gaps still remain in our knowledge of the disease's complexity. A crucial aspect is the impact of airborne factors over a lifetime, which often results in a complex overlap of phenotypes associated with type 2 (T2), non-T2 and mixed inflammation. Evidence now shows overlaps between the phenotypes associated with T2, non-T2 and mixed T2/non-T2 inflammation. These interconnections could be induced by different determinants such as recurrent infections, environmental factors, T-helper plasticity and comorbidities, collectively resulting in a complex network of distinct pathways generally considered as mutually exclusive. In this scenario, we need to abandon the concept of asthma as a disease characterised by distinct traits grouped into static segregated categories. It is now evident that there are multiple interplays between the various physiologic, cellular and molecular features of asthma, and the overlap of phenotypes cannot be ignored.

Effects of Oxidative Stress on Airway Epithelium Permeability in Asthma and Potential Implications for Patients with Comorbid Obesity

20 million adults and 4.2 million children in the United States have asthma, a disease resulting in inflammation and airway obstruction in response to various factors, including allergens and pollutants and nonallergic triggers. Obesity, another highly prevalent disease in the US, is a major risk factor for asthma and a significant cause of oxidative stress throughout the body. People with asthma and comorbid obesity are susceptible to developing severe asthma that cannot be sufficiently controlled with current treatments. More research is needed to understand how asthma pathobiology is affected when the patient has comorbid obesity. Because the airway epithelium directly interacts with the outside environment and interacts closely with the immune system, understanding how the airway epithelium of patients with asthma and comorbid obesity is altered compared to that of lean asthma patients will be crucial for developing more effective treatments. In this review, we discuss how oxidative stress plays a role in two chronic inflammatory diseases, obesity and asthma, and propose a mechanism for how these conditions may compromise the airway epithelium.

Delineating asthma according to inflammation phenotypes with a focus on paucigranulocytic asthma

ABSTRACT

Asthma is characterized by chronic airway inflammation and airway hyper-responsiveness. However, the differences in pathophysiology and phenotypic symptomology make a diagnosis of "asthma" too broad hindering individualized treatment. Four asthmatic inflammatory phenotypes have been identified based on inflammatory cell profiles in sputum: eosinophilic, neutrophilic, paucigranulocytic, and mixed-granulocytic. Paucigranulocytic asthma may be one of the most common phenotypes in stable asthmatic patients, yet it remains much less studied than the other inflammatory phenotypes. Understanding of paucigranulocytic asthma in terms of phenotypic discrimination, distribution, stability, surrogate biomarkers, underlying pathophysiology, clinical characteristics, and current therapies is fragmented, which impedes clinical management of patients. This review brings together existing knowledge and ongoing research about asthma phenotypes, with a focus on paucigranulocytic asthma, in order to present a comprehensive picture that may clarify specific inflammatory phenotypes and thus improve clinical diagnoses and disease management.

Parkin promotes airway inflammatory response to interferon gamma

Background

Increased type 2 interferon (i.e., IFN-γ) signaling has been shown to be involved in airway inflammation in a subset of asthma patients who often show high levels of airway neutrophilic inflammation and poor response to corticosteroid treatment. How IFN-γ mediates airway inflammation in a mitochondrial dysfunction setting (e.g., Parkin up-regulation) remains poorly understood. The goal of this study was to determine the role of Parkin, an E3 ubiquitin ligase, in IFN-γ-mediated airway inflammation and the regulation of Parkin by IFN-γ.

Results

Using a mouse model of IFN-γ treatment in wild-type and Parkin knockout mice, and cultured human primary airway epithelial cells with or without Parkin gene deficiency, we found that Parkin was necessary for the production of neutrophil chemokines (i.e., KC and IL-8) and airway neutrophilic inflammation. Mechanistically, Parkin was induced by IFN-γ treatment both in vivo and in vitro, which was associated with less expression of a Parkin transcriptional repressor Thap11. Overexpression of Thap11 inhibited Parkin expression in IFN-γ-stimulated airway epithelial cells.

Conclusions

Our data suggests a novel mechanism by which IFN-γ induces airway neutrophilic inflammation through the Thap11/Parkin axis. Inhibition of Parkin expression or activity may provide a new therapeutic target for the treatment of excessive neutrophilic inflammation in an IFN-γ high environment.

Differentially expressed microRNAs in peripheral blood cell are associated with downregulated expression of IgE in nonallergic childhood asthma

Childhood asthma is a heterogeneous disease characterized by chronic airway inflammation, leading to a broad range of clinical presentations. Nonallergic asthma is asthma without allergic sensitization. Both clinical manifestations and immunopathological mechanisms of nonallergic childhood asthma were rarely investigated. We aimed to compare the clinical features between nonallergic and allergic childhood asthma and apply microRNA to explore the underlying mechanism of nonallergic childhood asthma. We enrolled 405 asthmatic children (76 nonallergic, 52 allergic with total IgE < 150 IU/mL and 277 allergic with total IgE > 150 IU/mL). Clinical characteristics were compared between groups. Comprehensive miRNA sequencing (RNA-seq) was performed using peripheral blood from 11 nonallergic and 11 allergic patients with elevated IgE, respectively. Differentially expressed miRNA (DEmiRNA) were determined with DESeq2. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis was performed to determine functional pathways involved. Publicly available mRNA expression data was applied to investigate the predicted target mRNA networks via Ingenuity Pathway Analysis (IPA). The average age of nonallergic asthma was significantly younger (5.614 ± 2.743 vs 6.676 ± 3.118 years-old). Higher severity and worse control were more common in nonallergic asthma (two-way ANOVA, P < 0.0001). Long-term severity was higher, and intermittent attacks persisted in nonallergic patients. We identified 140 top DEmiRNAs based on false discovery rate (FDR) q-value < 0.001. Forty predicted target mRNA gene were associated with nonallergic asthma. The enriched pathway based on GO included Wnt signaling pathway. IgE expression was predicted to be downregulated by a network involving simultaneous interaction with IL-4, activation of IL-10 and inhibition of FCER2. Nonallergic childhood asthma were distinct in their younger age, higher long-term severity and more persistent course. Differentially expressed miRNA signatures associate with downregulation of total IgE expression and predicted target mRNA genes related molecular networks contribute to canonical pathways of nonallergic childhood asthma. We demonstrated the negative role of miRNAs involved in regulating IgE expression indicating differences between asthma phenotypes. Identification of biomarkers of miRNAs could contribute to understand the molecular mechanism of endotypes in nonallergic childhood asthma, which can potentially allow delivery of precision medicine to pediatric asthma.

The "Asthma-Polycystic Ovary Overlap Syndrome" and the Therapeutic Role of Myo-Inositol

Asthma is a heterogeneous inflammatory disease characterized by abnormalities in immune response. Due to the inherent complexity of the disease and the presence of comorbidities, asthma control is often difficult to obtain. In asthmatic patients, an increased prevalence of irregular menstrual cycles, infertility, obesity, and insulin resistance has been reported. Given that these conditions are also common in patients with polycystic ovary syndrome (PCOS), we propose the definition of "asthma-PCOS overlap syndrome" to indicate a medical condition which shares characteristics of both diseases. The aim of this review is to analyze the links between asthma and PCOS and evaluate the therapeutic role of myo-inositol, a natural compound currently utilized in patients with PCOS, in the management of asthma patients.

Self-Reported Insufficient Sleep Is Associated With Clinical and Inflammatory Features of Asthma: A Prospective Cohort Study

BACKGROUND

A few studies have explored the association between short sleep duration and worse asthma outcomes in patients with self-reported asthma; however, all of them were cross-sectional.

OBJECTIVES

To investigate the association between self-reported sleep duration and asthma-related clinical and inflammatory characteristics and whether sleep duration is associated with asthma exacerbations (AEs) in the following year.

METHODS

A prospective cohort study consecutively recruited participants with asthma, who were classified into short (n = 58), normal (n = 380), and long (n = 84) sleep duration groups. We investigated the clinical and inflammatory characteristics and exacerbations within a 1-year follow-up.

RESULTS

Patients with short sleep duration were older and had significantly lower total IgE and FeNO levels and higher airway inflammation, characterized by increased levels of IL-6 and TNF-α in sputum than those of patients with normal sleep duration. Furthermore, they had a significantly increased risk for poorly controlled asthma (adjusted odds ratio = 2.741; 95% CI, 1.379-5.447; P = .004) and moderate to severe AEs (adjusted incidence rate ratio = 1.798; 95% CI, 1.098-2.942; P = .020).

CONCLUSIONS

Short sleep duration was associated with non-type 2 inflammation and is an independent risk factor for future AEs. Therefore, as a potentially treatable trait, sleep duration may have clinical implications for asthma management.

Baseline Characteristics of Patients Enrolled in Clinical Trials of Biologics for Severe Asthma as Potential Predictors of Outcomes

(1) Background: Over the past 20 years, monoclonal antibodies have been developed for the treatment of severe asthma, with numerous randomised controlled trials (RCTs) conducted to define their safety and efficacy. The growing availability of biologics, which until now have only been available for T2-high asthma, has been further enriched by the arrival of tezepelumab. (2) Methods: This review aims to evaluate the baseline characteristics of patients enrolled in RCTs of biologics for severe asthma to understand how they could potentially predict outcomes and how they can help differentiate between available options. (3) Results: The studies reviewed demonstrated that all biologic agents are effective in improving asthma control, especially with regard to reducing exacerbation rates and OCS use. As we have seen, in this regard, there are few data on omalizumab and none yet on tezepelumab. In analysing exacerbations and average doses of OCSs, pivotal studies on benralizumab have enrolled more seriously ill patients. Secondary outcomes, such as improvement in lung function and quality of life, showed better results-especially for dupilumab and tezepelumab. (4) Conclusion: Biologics are all effective, albeit with important differences. What fundamentally guides the choice is the patient's clinical history, the endotype represented by biomarkers (especially blood eosinophils), and comorbidities (especially nasal polyposis).

Evaluating the effects of vitamin D Level on airway obstruction in two asthma endotypes in humans and in two mouse models with different intake of vitamin D during early-life

Introduction

Asthma is primarily divided into two categories: type 2 (T2-high) and non-type 2 (T2-low). A relationship between asthma severity and vitamin D deficiency has been identified, but its impact on each asthma endotype remains unknown.

Methods

We clinically examined the influence of vitamin D on patients with T2-high (n = 60) or T2-low asthma (n = 36) compared with controls (n = 40). Serum 25(OH)D levels, inflammatory cytokines and spirometry were measured. Mouse models were then used to further analyze the effects of vitamin D on both asthmatic endotypes. BALB/c mice were fed with vitamin D-deficient (LVD), -sufficient (NVD), or -supplemented diets (HVD) throughout lactation and offspring followed the same diet after weaning. Offspring were sensitized/challenged with ovalbumin (OVA) to establish "T2-high" asthma or OVA combined with ozone exposure (OVA + ozone) to induce "T2-low" asthma. Spirometry and serum, bronchoalveolar lavage fluid (BALF), and lung tissues were analyzed.

Results

Serum 25(OH)D levels were decreased in asthmatic patients compared with controls. Patients with vitamin D deficiency (Lo) had varying degrees of elevation of the pro-inflammatory cytokines IL-5, IL-6, and IL-17A, decreased expression of the anti-inflammatory cytokine IL-10, and altered forced expiratory volume in the first second as a percentage of predicted value (FEV₁%pred) in both asthmatic endotypes. Vitamin D status had a stronger correlation with FEV₁%pred in T2-low asthma than T2-high asthma, and 25(OH)D level was only positively linked to maximal mid-expiratory flow as a percentage of predicted value (MMEF%pred) in the T2-low group. Inflammation, hyperresponsiveness, and airway resistance (R_L) was increased in both asthma models compared with controls while vitamin D deficiency further increased airway inflammation and airway obstruction. These findings were particularly prominent in T2-low asthma.

Discussion

The potential function and mechanisms of vitamin D and both asthma endotypes should be studied individually, and further analysis of the potential signaling pathways involved with vitamin D on T2-low asthma is warranted.

Age-Related Clinical Characteristics, Inflammatory Features, Phenotypes, and Treatment Response in Asthma

BACKGROUND

Emerging evidence suggests that aging affects asthma outcomes, but the mechanism remains largely unexplored.

OBJECTIVE

To explore age-related clinical characteristics, inflammatory features, phenotypes, and treatment response in asthma.

METHODS

This was a prospective cohort study of asthmatic patients with a 12-month follow-up in a real-world setting. Clinical inflammatory and phenotypic characteristics, future risk for exacerbations, and treatment response were assessed across different age groups (young was defined as age 18 to 39 years; middle-aged, 40 to 64 years; and elderly, 65 years or older).

RESULTS

Compared with young (n = 106) and middle-aged (n = 179) asthmatic patients, elderly patients (n = 55) had worse airway obstruction, more comorbidities including chronic obstructive pulmonary disease and diabetes, less atopy, and lower levels of IgE and FeNO, and were more likely to have late-onset and fixed airflow obstruction asthma and a reduced risk for having type 2 profile asthma. Levels of IFN-gamma, IL-17A, and IL-8 in induced sputum were significantly increased in elderly asthmatic patients (all P < .05). Path analysis indicated that age directly and significantly led to future exacerbations in asthma, partially mediated by an upregulation of airway IFN-gamma. Moreover, elderly patients with asthma had a reduced treatment response (improvement in FEV₁ of 12% or greater, or 200 mL, and a reduction in Borg scores of 1 or greater) (adjusted odds ratio = 0.11; 95% CI, 0.02-0.52; and adjusted odds ratio = 0.12; 95% CI, 0.03-0.49, respectively).

CONCLUSIONS

This study confirms that asthma in the elderly population represents a specific phenotype and indicates that aging can influence asthma in terms of clinical characteristics, inflammatory features, exacerbations, and treatment response.

Current evaluation and management of patients with chronic rhinosinusitis and nasal polyps

INTRODUCTION

A clear understanding of the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNP) and its close association with other airway pathologies, especially asthma, helps to comprehend the concept of the united airway and the importance of a multidisciplinary approach and the actual roll of biologic therapy.

AREAS COVERED

This expert review is the synthesis of a working group on the current state of the art of the evaluation and management of CRSwNP. A thorough analysis of the literature has been conducted for the latest studies and results, specially the European (EPOS 2020) and American (ICAR-RS 2021) guidelines.

EXPERT OPINION

The roles of optimal medical treatment and indications for surgery are becoming clearer, but much research is still needed regarding the extent and radicality when surgery is indicated. The main objectives of this review were to provide a clear and updated description of treatments, their indication, follow-up, and response criteria. These steps are considering the broad spectrum of inflammation endophenotypes and the biologic therapy available. Understanding the role and limitations of each specialty is key for providing greatest benefit to the patient.

Increased Oxidative Stress in Asthma-Relation to Inflammatory Blood and Lung Biomarkers and Airway Remodeling Indices

Airway inflammation in asthma is related to increased reactive oxygen species generation, potentially leading to tissue injury and subsequent airway remodeling. We evaluated oxidative stress in peripheral blood from asthmatic subjects (n = 74) and matched controls (n = 65), using recently developed real-time monitoring of the protein hydroperoxide (HP) formation by the coumarin boronic acid (CBA) assay. We also investigated the relation of the systemic oxidative stress response in asthma to disease severity, lung function, airway remodeling indices (lung computed tomography and histology), and blood and bronchoalveolar lavage fluid (BAL) inflammatory biomarkers. We documented enhanced systemic oxidative stress in asthma, reflected by 35% faster and 58% higher cumulative fluorescent product generation in the CBA assay (p < 0.001 for both). The dynamics of HP generation correlated inversely with lung function but not with asthma severity or histological measures of airway remodeling. HP generation was associated positively with inflammatory indices in the blood (e.g., C-reactive protein) and BAL (e.g., interleukin [IL]-6, IL-12p70, and neutrophil count). Bronchial obstruction, thicker airway walls, increased BAL IL-6, and citrullinated histone 3 in systemic circulation independently determined increased HP formation. In conclusion, a real-time CBA assay showed increased systemic HP generation in asthma. In addition, it was associated with inflammatory biomarkers, suggesting that proper disease control can also lead to a decrease in oxidative stress.

Cigarette Smoking and Asthma

Globally, around half the adult asthma population are current or former cigarette smokers. Cigarette smoking and asthma interact to induce an "asthma-smoking phenotype(s)," which has important implications for diagnosis, pathogenic mechanisms, and management. The lack of progress in understanding the effects of smoking on adults with asthma is due in part to their exclusion from most investigative studies and large clinical trials. In this review, we summarize the adverse clinical outcomes associated with cigarette smoking in asthma, highlight challenges in diagnosing asthma among cigarette smokers with chronic respiratory symptoms, particularly in older individuals with a long-standing smoking history, and review pathogenic mechanisms involving smoking- and asthma-related airway inflammation, tissue remodeling, corticosteroid insensitivity, and low-grade systemic inflammation. We discuss the key components of management including the importance of smoking cessation strategies, evidence for the effectiveness of the Global Initiative for Asthma recommendations on treatment in cigarette smokers, and the role of treatable traits such as type 2 eosinophilic airway inflammation. Lastly, we provide an algorithm to aid clinicians to manage current and former smokers with asthma. In the future, controlled and pragmatic trials in real-world populations should include cigarette smokers with asthma to provide an evidence base for treatment recommendations.

Which Therapy for Non-Type(T)2/T2-Low Asthma

Currently, the asthmatic population is divided into Type 2-high and non-Type 2/Type 2-low asthmatics, with 50% of patients belonging to one of the two groups. Differently from T2-high, T2-low asthma has not been clearly defined yet, and the T2-low patients are identified on the basis of the absence or non-predominant expression of T2-high biomarkers. The information about the molecular mechanisms underpinning T2-low asthma is scarce, but researchers have recognized as T2-low endotypes type 1 and type 3 immune response, and remodeling events occurring without inflammatory processes. In addition, the lack of agreed biomarkers reprents a challenge for the research of an effective therapy. The first-choice medication is represented by inhaled corticosteroids despite a low efficacy is reported for/in T2-low patients. However, macrolides and long-acting anti-muscarinic drugs have been recognized as efficacious. In recent years, clinical trials targeting biomarkers playing key roles in T3 and T1 immune pathways, alarmins, and molecules involved in neutrophil recruitment have provided conflicting results probably misleading (or biased) in patients' selection. However, further studies are warranted to achieve a precise characterization of T2-low asthma with the aim of defining a tailored therapy for each single asthmatic patient.