Different endotypes and phenotypes drive the heterogeneity in severe asthma

Exploring the therapeutic potential of monoclonal antibodies targeting TSLP and IgE in asthma management

BACKGROUND

In recent years, there has been a growing interest in the utilization of biologic therapies for the management of asthma. Both TSLP and IgE are important immune molecules in the development of asthma, and they are involved in the occurrence and regulation of inflammatory response.

METHODS

A comprehensive search of PubMed and Web of Science was conducted to gather information on anti-TSLP antibody and anti-IgE antibody.

RESULTS

This investigation elucidates the distinct mechanistic roles of Thymic Stromal Lymphopoietin (TSLP) and Immunoglobulin E (IgE) in the pathogenesis of asthma, with a particular emphasis on delineating the therapeutic mechanisms and pharmacological properties of monoclonal antibodies targeting IgE and TSLP. Through a meticulous examination of clinical trials involving paradigmatic agents such as omalizumab and tezepelumab, we offer valuable insights into the potential treatment modalities for diseases with shared immunopathogenic pathways involving IgE and TSLP.

CONCLUSION

The overarching objective of this comprehensive study is to delve into the latest advancements in asthma therapeutics and to provide guidance for future investigations in this domain.

Real-world biologics response and super-response in the International Severe Asthma Registry cohort

BACKGROUND

Biologic asthma therapies reduce exacerbations and long-term oral corticosteroids (LTOCS) use in randomized controlled trials (RCTs); however, there are limited data on outcomes among patients ineligible for RCTs. Hence, we investigated responsiveness to biologics in a real-world population of adults with severe asthma.

METHODS

Adults in the International Severe Asthma Registry (ISAR) with ≥24 weeks of follow-up were grouped into those who did, or did not, initiate biologics (anti-IgE, anti-IL5/IL5R, anti-IL4/13). Treatment responses were examined across four domains: forced expiratory volume in 1 second (FEV1) increase by ≥100 mL, improved asthma control, annualized exacerbation rate (AER) reduction ≥50%, and any LTOCS dose reduction. Super-response criteria were: FEV1 increase by ≥500 mL, new well-controlled asthma, no exacerbations, and LTOCS cessation or tapering to ≤5 mg/day.

RESULTS

5.3% of ISAR patients met basic RCT inclusion criteria; 2116/8451 started biologics. Biologic initiators had worse baseline impairment than non-initiators, despite having similar biomarker levels. Half or more of initiators had treatment responses: 59% AER reduction, 54% FEV1 increase, 49% improved control, 49% reduced LTOCS, of which 32%, 19%, 30%, and 39%, respectively, were super-responses. Responses/super-responses were more frequent in biologic initiators than in non-initiators; nevertheless, ~40-50% of initiators did not meet response criteria.

CONCLUSIONS

Most patients with severe asthma are ineligible for RCTs of biologic therapies. Biologics are initiated in patients who have worse baseline impairments than non-initiators despite similar biomarker levels. Although biologic initiators exhibited clinical responses and super-responses in all outcome domains, 40-50% did not meet the response criteria.

Comorbid functional dyspepsia reflects IL-33-mediated airway neuronal dysfunction in asthma

BACKGROUND

Neuronal dysfunction is implicated in the pathophysiology of asthma and functional dyspepsia (FD). However, the relationship between these diseases remains unclear.

OBJECTIVE

This study aimed to clarify the clinical implications of comorbid FD in asthma and to explore the unified pathway between asthma and FD by focusing on airway neuronal dysfunction.

METHODS

Clinical indices and biomarkers, including capsaicin cough sensitivity (C-CS), were compared between patients with asthma with and without FD. C-CS was determined on the basis of capsaicin concentration that induced at least 2 coughs (C2) or 5 coughs (C5). Additionally, the associations of airway inflammation with airway innervation and gastrointestinal motility were evaluated in mouse models of type 2 airway inflammation.

RESULTS

Patients with asthma with FD had worse asthma control and cough severity and lower C2 and C5 thresholds than those without FD. The severity of FD symptoms was negatively correlated with C2 and C5 thresholds. FD and poor asthma control were predictors of heightened C-CS (defined as C5 ≤ 2.44 μmol) in asthma. A mouse model of papain-induced airway inflammation developed airway hyperinnervation and gastrointestinal dysmotility, and both pathologies were ameliorated by an anti-IL-33 antibody. Moreover, papain-induced gastrointestinal dysmotility was mitigated by silencing the airway sensory neurons using QX-314, a sodium channel blocker. Furthermore, sputum IL-33 levels were significantly elevated in patients with asthma with FD or heightened C-CS compared to their counterparts.

CONCLUSION

FD is significantly associated with airway neuronal dysfunction in asthma. IL-33-mediated airway neuronal dysfunction may contribute to the interaction between asthma and FD.

Phenotyping of Severe Asthma in the Era of Broad-Acting Anti-Asthma Biologics

Severe asthma is associated with significant morbidity and mortality despite the maximal use of inhaled corticosteroids and additional controller medications, and has a high economic burden. Biologic therapies are recommended for the management of severe, uncontrolled asthma to help to prevent exacerbations and to improve symptoms and health-related quality of life. The effective management of severe asthma requires consideration of clinical heterogeneity that is driven by varying clinical and inflammatory phenotypes, which are reflective of distinct underlying disease mechanisms. Phenotyping patients using a combination of clinical characteristics such as the age of onset or comorbidities and biomarker profiles, including blood eosinophil counts and levels of fractional exhaled nitric oxide and serum total immunoglobulin E, is important for the differential diagnosis of asthma. In addition, phenotyping is beneficial for risk assessment, selection of treatment, and monitoring of the treatment response in patients with asthma. This review describes the clinical and inflammatory phenotypes of asthma, provides an overview of biomarkers routinely used in clinical practice and those that have recently been explored for phenotyping, and aims to assess the value of phenotyping in severe asthma management in the current era of biologics.

Disease-associated immune cell endotypes in anti-MDA5-positive dermatomyositis using unbiased hierarchical clustering

Objective

Clinical and prognostic features of Anti-MDA5-Positive Dermatomyositis (MDA5+ DM) are diverse. This study aimed to examine the peripheral immune cell profiles of patients with MDA5+ DM, identify disease endotypes related to the heterogeneous manifestations and prognosis, and guide individualized therapy regimen.

Methods

This inpatient cohort included 123 patients with MDA5+ DM. Unsupervised hierarchical clustering analysis was used to derive disease endotypes from the circulating immune cell profiles on admission. Clinical symptoms, laboratory test results, inpatient treatments, and disease outcomes were then analyzed among the identified endotypes.

Results

Three disease endotypes in MDA5+ DM were identified from peripheral immune cell profiles. Endotype1 had the highest percentages of CD4+ T cells and monocytes, and the lowest percentage of neutrophils; Endotype2 had the highest percentage of B cells; Endotype3 had the highest percentage of CD8+ T cells and NK cells. Clinical and prognostic heterogeneity of the endotypes were revealed. Endotype1 had the lowest 3-month mortality with the high incidence of periungual capillary changes. Endotype2 and Endotype3 had higher prevalence of rapidly progressive interstitial lung disease (RPILD) and mortality at 3 months than Endotype1. Meanwhile, Endotype3 had higher pneumocystis jiroveci and CMV viremia cases with significantly elevated of activated CD8+ T cells and multiple cytokines than Endotype1.

Conclusion

Clustering analysis of peripheral immune cell profiles identified three different endotypes in MDA5+ dermatomyositis. Endotpye2 and 3 showed higher RPILD, 3-month mortality, pneumocystis jiroveci and CMV viremia.

Factors influencing poor response to type 2 targeted therapies in severe asthma: a retrospective cohort study

BACKGROUND

A significant breakthrough has been made in treating severe asthma, with the recognition of various asthma phenotypes and an updated management guideline. Type 2 targeted therapies, such as benralizumab and omalizumab; have been identified as an effective treatment for severe asthma, improving patient response, lung function tests and asthma symptom control. This study aimed to evaluate factors contributing to poor response to therapy.

METHODS

A retrospective single-center cohort study of 162 patients with severe asthma who started biologic therapy; their data were retrieved from medical records for further analysis. Poor responders were patients remained clinically and functionally uncontrolled despite even after augmenting all treatment options.

RESULTS

Childhood-onset asthma, bronchiectasis, poor symptom control (ACT below 19), severe airway obstruction (< 60% predicted), and maintenance oral corticosteroid (mOCS) use were significantly associated with poor response to omalizumab and benralizumab; p = 0.0.4 and 0.01; 0.003 and 0.01; 0.01 and 0.001, 0.05 and 0.04; 0.006 and 0.02, respectively. However, chronic rhinosinusitis and IgE < 220kIU/L were associated with higher poor response rates to omalizumab (p = 0.01 and 0.04, respectively). At the same time, female patients and those with blood eosinophils level < 500 cells/mm3 had a higher poor response rate to benralizumab (p = 0.02 and 0.01, respectively). Ischemic heart disease (IHD), bronchiectasis, and continued use of OCS increased the likelihood of poor response to omalizumab by 21, 7, and 24 times (p = 0.004, 0.008, and 0.004, respectively). In contrast, the female gender, childhood-onset asthma and higher BMI increased the likelihood of poor response to benralizumab by 7, 7 and 2 times more, p = 0.03, 0.02 and 0.05, respectively.

CONCLUSION

Poor response to omalizumab treatment was independently associated with ischemic heart disease (IHD), bronchiectasis, and a history of maintenance oral corticosteroid (mOCS) use. Conversely, poor response to benralizumab therapy was independently linked to female gender, childhood-onset asthma and higher body mass index (BMI).

Omalizumab Transitions in Severe Asthma: Factors Influencing Switching Decisions and Timing for Optimal Response

OBJECTIVE

The objective of this study was to assess the effectiveness of switching from omalizumab to another biologic therapy for patients with severe asthma and evaluate factors that influenced the decision to switch and determined the optimal time for a good biologic response.

SUBJECTS AND METHODS

A retrospective study of severe asthma patients was conducted at Al-Rashed Allergy Center, a tertiary center in Kuwait. After meeting the eligibility criteria, patients were divided into two comparative groups: those continuing with omalizumab and those who started with omalizumab but switched to another biologic.

RESULTS

One hundred sixteen patients with severe asthma were recruited, and only 33 had access to multiple biological treatments. Approximately 22.4% switched from omalizumab. Male patients with a history of ischemic heart disease, chronic rhinosinusitis, and nasal polyps were more likely to switch if they had higher levels of eosinophils in the sputum. This study showed that every 1% increase in sputum eosinophils doubled the likelihood of a switch. Patients with access to alternative biological options had a much shorter mean duration of omalizumab therapy before switching compared to those with only affordable omalizumab: 4.9 ± 1.5 years versus 8.9 ± 1.3 years (p < 0.001). The optimal time to predict the likelihood of a good response was less than 5.5 years, with an area under the curve of 0.91 and p = 0.003. This cutoff point provided a sensitivity and specificity of approximately 89% and 100%, respectively.

CONCLUSION

An early transition from omalizumab, specifically within the first 5 years of treatment, in patients with severe asthma and higher sputum eosinophils may enhance the likelihood of a good response if other biological therapies were available.

A Decade of Pathogenesis Advances in Non-Type 2 Inflammatory Endotypes in Chronic Rhinosinusitis: 2012-2022

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by localized inflammation of the upper airways. CRS includes two main phenotypes, namely, CRS with nasal polyps and CRS without nasal polyps. The phenotype-based classification method cannot reflect the pathological mechanism. The endotype-based classification method has been paid more and more attention by researchers. It is mainly divided into type 2 and non-type 2 endotypes. The mechanism driving the pathogenesis of non-type 2 inflammation is currently unknown. In this review, the PubMed and Web of Science databases were searched to conduct a critical analysis of representative literature works on the pathogenesis of non-type 2 inflammation in CRS published in the past decade. This review summarizes the latest evidence that may lead to the pathogenesis of non-type 2 inflammation. It is the main method that analyzing the pathogenesis from the perspective of immunology. Genomics and proteomics technique provide new approaches to the study of the pathogenesis. Due to differences in race, environment, geography, and living habits, there are differences in the occurrence of non-type 2 inflammation, which increase the difficulty of understanding the pathogenesis of non-type 2 inflammation in CRS. Studies have confirmed that non-type 2 endotype is more common in Asian patients. The emergence of overlap and unclassified endotypes has promoted the study of heterogeneity in CRS. In addition, as the source of inflammatory cells and the initiation site of the inflammatory response, microvessels and microlymphatic vessels in the nasal mucosal subepithelial tissue participate in the inflammatory response and tissue remodeling. It is uncertain whether CRS patients affect the risk of infection with SARS-CoV-2. In addition, the pathophysiological mechanism of non-type 2 CRS combined with COVID-19 remains to be further studied, and it is worth considering how to select the befitting biologics for CRS patients with non-type 2 inflammation.

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".

Obese Asthma Phenotype Is Associated with hsa-miR-26a-1-3p and hsa-miR-376a-3p Modulating the IGF Axis

Clarifying inflammatory processes and categorising asthma into phenotypes and endotypes improves asthma management. Obesity worsens severe asthma and reduces quality of life, although its specific molecular impact remains unclear. We previously demonstrated that hsa-miR-26a-1-3p and hsa-miR-376a-3p, biomarkers related to an inflammatory profile, discriminate eosinophilic from non-eosinophilic asthmatics. We aimed to study hsa-miR-26a-1-3p, hsa-miR-376a-3p, and their target genes in asthmatic subjects with or without obesity to find biomarkers and comprehend obese asthma mechanisms. Lung tissue samples were obtained from asthmatic patients (n = 16) and healthy subjects (n = 20). We measured miRNA expression using RT-qPCR and protein levels (IGF axis) by ELISA in confirmation samples from eosinophilic (n = 38) and non-eosinophilic (n = 39) obese (n = 26) and non-obese (n = 51) asthma patients. Asthmatic lungs showed higher hsa-miR-26a-1-3p and hsa-miR-376a-3p expression than healthy lungs. A study of seven genes regulated by these miRNAs revealed differential expression of IGFBP3 between asthma patients and healthy individuals. In obese asthma patients, we found higher hsa-miR-26a-1-3p and IGF-1R values and lower values for hsa-miR-376a-3p and IGFBP-3. Hsa-miR-26a-1-3p and IGFBP-3 were directly and inversely correlated with body mass index, respectively. Hsa-miR-26a-1-3p and hsa-miR-376a-3p could be used as biomarkers to phenotype patients with eosinophilic and non-eosinophilic asthma in relation to comorbid obesity.

Bronchial thermoplasty improves cough hypersensitivity and cough in severe asthmatics

BACKGROUND

Cough is a troublesome symptom of asthma because it is associated with disease severity and poor asthma control. Bronchial thermoplasty (BT) may be effective in improving cough severity and cough-related quality of life in severe uncontrolled asthma.

OBJECTIVE

To evaluate the efficacy of BT for cough in severe uncontrolled asthma.

METHODS

Twelve patients with severe uncontrolled asthma were enrolled in this study between 2018 May and March 2021 and arbitrarily divided into cough-predominant [cough severity Visual Analog Scale (VAS) ≥ 40 mm, n = 8] and typical asthma (cough VAS <40 mm, n = 4) groups. Clinical parameters, such as capsaicin cough sensitivity [C-CS: the concentrations to inhaled capsaicin required to induce at least two (C2) and five (C5) coughs], lung function, and type-2-related biomarkers (fractional nitric oxides and absolute eosinophil counts) and cough-related indices [cough severity VAS and the Leicester Cough Questionnaire (LCQ)] were evaluated before and 3 months after performing BT.

RESULTS

BT significantly improved both cough-related indices and C-CS in the cough-predominant group. Changes in C-CS were significantly correlated with changes in the LCQ scores (C5: r = 0.65, p = 0.02 for all patients, and r = 0.81, p = 0.01 for the cough-predominant group).

CONCLUSIONS

BT may be effective for cough in severe uncontrolled asthma by improving C-CS. However, further larger cohort studies are necessary to confirm the effect of BT for cough in asthma.

CLINICAL TRIAL REGISTRATION

This study was registered in the UMIN Clinical Trials Registry (Registry ID UMIN: 000031982).

New insights into the pathophysiology and therapeutic targets of asthma and comorbid chronic rhinosinusitis with or without nasal polyposis

Asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) or without (CRSsNP) are chronic respiratory diseases. These two disorders often co-exist based on common anatomical, immunological, histopathological, and pathophysiological basis. Usually, asthma with comorbid CRSwNP is driven by type 2 (T2) inflammation which predisposes to more severe, often intractable, disease. In the past two decades, innovative technologies and detection techniques in combination with newly introduced targeted therapies helped shape our understanding of the immunological pathways underlying inflammatory airway diseases and to further identify several distinct clinical and inflammatory subsets to enhance the development of more effective personalized treatments. Presently, a number of targeted biologics has shown clinical efficacy in patients with refractory T2 airway inflammation, including anti-IgE (omalizumab), anti-IL-5 (mepolizumab, reslizumab)/anti-IL5R (benralizumab), anti-IL-4R-α (anti-IL-4/IL-13, dupilumab), and anti-TSLP (tezepelumab). In non-type-2 endotypes, no targeted biologics have consistently shown clinical efficacy so far. Presently, multiple therapeutical targets are being explored including cytokines, membrane molecules and intracellular signalling pathways to further expand current treatment options for severe asthma with and without comorbid CRSwNP. In this review, we discuss existing biologics, those under development and share some views on new horizons.

Asthma: The Use of Animal Models and Their Translational Utility

Asthma is characterized by chronic lower airway inflammation that results in airway remodeling, which can lead to a permanent decrease in lung function. The pathophysiology driving the development of asthma is complex and heterogenous. Animal models have been and continue to be essential for the discovery of molecular pathways driving the pathophysiology of asthma and novel therapeutic approaches. Animal models of asthma may be induced or naturally occurring. Species used to study asthma include mouse, rat, guinea pig, cat, dog, sheep, horse, and nonhuman primate. Some of the aspects to consider when evaluating any of these asthma models are cost, labor, reagent availability, regulatory burden, relevance to natural disease in humans, type of lower airway inflammation, biological samples available for testing, and ultimately whether the model can answer the research question(s). This review aims to discuss the animal models most available for asthma investigation, with an emphasis on describing the inciting antigen/allergen, inflammatory response induced, and its translation to human asthma.

Development of an inhaled anti-TSLP therapy for asthma

Thymic stromal lymphopoietin (TSLP), an epithelial cell-derived cytokine, acts as a key mediator in airway inflammation and modulates the function of multiple cell types, including dendritic cells and group 2 innate lymphoid cells. TSLP plays a role in asthma pathogenesis as an upstream cytokine, and data suggest that TSLP blockade with the anti-TSLP monoclonal antibody, tezepelumab, could be efficacious in a broad asthma population. Currently approved asthma biologic therapies target allergic or eosinophilic disease and require phenotyping; therefore, an unmet need exists for a therapy that can address Type 2 (T2)-high and T2-low inflammation in asthma. All currently approved biologic treatments are delivered intravenously or subcutaneously; an inhaled therapy route that allows direct targeting of the lung with reduced systemic impact may offer advantages. Currently in development, ecleralimab (CSJ117) represents the first inhaled anti-TSLP antibody fragment that binds soluble TSLP and prevents TSLP receptor activation, thereby inhibiting further inflammatory signalling cascades. This anti-TSLP antibody fragment is being developed for patients with severe uncontrolled asthma despite standard of care inhaled therapy. A Phase IIa proof of concept study, using allergen bronchoprovocation as a model for asthma exacerbations, found that ecleralimab was well-tolerated and reduced allergen-induced bronchoconstriction in adult patients with mild asthma. These results suggest ecleralimab may be a promising, new therapeutic class for asthma treatment.

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.

Decreased capsaicin cough reflex sensitivity predicts hospitalisation due to COPD

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) are often hospitalised due to severe acute exacerbation (AE) or community-acquired pneumonia (CAP). Previous studies revealed the association of cough reflex sensitivity with the pathophysiology of COPD and pneumonia. We hypothesised that cough reflex sensitivity may be associated with severe AE or CAP requiring hospitalisation in patients with COPD.

METHODS

We prospectively recruited 68 patients with COPD between June 2018 and January 2020. Patient characteristics, lung and cardiac functions, and biomarkers, including capsaicin cough reflex sensitivity and blood eosinophil count, were evaluated at enrolment. All participants were monitored for AE or CAP requiring hospitalisation for 12 months. We determined the risk factors and ORs for hospitalisation in patients with COPD using a multivariate analysis.

RESULTS

Eight patients experienced AE (n=3) or CAP (n=5) and required hospitalisation during follow-up. Patients in the hospitalisation+ group had higher modified Medical Research Council scores and blood eosinophil counts (≥300 µL) than those in the hospitalisation- group. Capsaicin cough reflex sensitivity tended to decrease in the hospitalisation+ group compared with that in the hospitalisation- group. Multivariate analysis revealed that a decreased capsaicin cough reflex and high eosinophil count (≥300 µL) were predictive risk factors for future hospitalisation due to AE-COPD or CAP.

CONCLUSION

In addition to eosinophils, decreased capsaicin cough reflex sensitivity was associated with hospitalisation due to AE-COPD or CAP. Capsaicin cough reflex sensitivity in patients with COPD may play a role in the prevention of severe AE or pneumonia requiring hospitalisation.

TRIAL REGISTRATION NUMBER

UMIN000032497.

Upper airway disease diagnosis as a predictive biomarker of therapeutic response to biologics in severe asthma

Asthma is a heterogeneous disease sharing airway instability but with different biology, risk factors, and response-to-therapy patterns. Biologics have revolutionized the one-size-fits-to-all approach to personalized medicine in severe asthma (SA), which relies on the identification of biomarkers that define distinct endotypes. Thus, blood eosinophils and, to some extent, exhaled nitric oxide (FeNO) can predict the response to approved anti-type 2 (T2) biologics (anti-IgE, anti-IL-5, and anti-IL-4R alpha), whereas age at onset and comorbidities such as anxiety/depression, obesity, reflux, and upper airway disease (UAD) also influence therapeutic responses in SA. In this article, focusing on the predictive value of biomarkers for the therapeutic response to biologics in SA, we first summarize the level of prediction achieved by T2 biomarkers (blood eosinophils, FeNO) and then review whether data support the predictive value of upper airway diagnosis on such outcomes. Post hoc analysis of most studies with T2 biologics suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) and, to a lower extent, allergic rhinitis may help in predicting clinical response. Considering that T2 biologics are now also approved for the treatment of severe CRSwNP, diagnosis of upper airway disease is a key step in determining eligibility for such therapy.

Fungal exposome, human health, and unmet needs: A 2022 update with special focus on allergy

Humans inhale, ingest, and touch thousands of fungi each day. The ubiquity and diversity of the fungal kingdom, reflected by its complex taxonomy, are in sharp contrast with our scarce knowledge about its distribution, pathogenic effects, and effective interventions at the environmental and individual levels. Here, we present an overview of salient features of fungi as permanent players of the human exposome and key determinants of human health, through the lens of fungal allergy and other fungal hypersensitivity reactions. Improved understanding of the fungal exposome sheds new light on the epidemiology of fungal-related hypersensitivity diseases, their immunological substratum, the currently available methods, and biomarkers for environmental and medical fungi. Unmet needs are described and potential approaches are highlighted as perspectives.

Recent insights in the role of biomarkers in severe asthma management

Contemporary asthma management requires a proactive and individualized approach, combining precision diagnosis and personalized treatment. The introduction of biologic therapies for severe asthma to everyday clinical practice, increases the need for specific patient selection, prediction of outcomes and monitoring of these costly and long-lasting therapies. Several biomarkers have been used in asthma in disease identification, prediction of asthma severity and prognosis, and response to treatment. Novel advances in the area of personalized medicine regarding disease phenotyping and endotyping, encompass the development and application of reliable biomarkers, accurately quantified using robust and reproducible methods. The availability of powerful omics technologies, together with integrated and network-based genome data analysis, and microbiota changes quantified in serum, body fluids and exhaled air, will lead to a better classification of distinct phenotypes or endotypes. Herein, in this review we discuss on currently used and novel biomarkers for the diagnosis and treatment of asthma.

Eosinophilic inflammation: An Appealing Target for Pharmacologic Treatments in Severe Asthma

Severe asthma is characterized by different endotypes driven by complex pathologic mechanisms. In most patients with both allergic and non-allergic asthma, predominant eosinophilic airway inflammation is present. Given the central role of eosinophilic inflammation in the pathophysiology of most cases of severe asthma and considering that severe eosinophilic asthmatic patients respond partially or poorly to corticosteroids, in recent years, research has focused on the development of targeted anti-eosinophil biological therapies; this review will focus on the unique and particular biology of the eosinophil, as well as on the current knowledge about the pathobiology of eosinophilic inflammation in asthmatic airways. Finally, current and prospective anti-eosinophil therapeutic strategies will be discussed, examining the reason why eosinophilic inflammation represents an appealing target for the pharmacological treatment of patients with severe asthma.

Clinical implications of asthma endotypes and phenotypes

Background: Asthma is a complex disorder with variable clinical expression. Recognizable clinical and laboratory features define phenotypes, and specific biologic pathways define endotypes. Identifying the specific pathway responsible for persistent asthma would enable the clinician to select the optimal inhibitors, which currently are biologic therapies. Objective: To provide an up-to-date review of the current clinical status of endotype and phenotype characterizations of asthma and discuss these categories in relation to the available, or likely available, biologic therapies for asthma. Methods: The medical literature was reviewed based on the search terms: asthma biologics, severe asthma, uncontrolled asthma, corticosteroid-dependent asthma, phenotype, endotype, and type 2. We also used our knowledge of the literature and current research. Results: All of the current biologics, including the recently approved tezepelumab, were most effective with increased type 2 biomarkers, which identify exacerbation-prone asthma. Current biomarkers do not permit consistent identification of specific endotypes to facilitate informed selection of the optimal therapy for an individual patient. Thus, empiricism and the art of care continue to play major roles in treatment selection. Conclusion: Current biologic therapies for asthma and those likely to be U.S. Food and Drug Administration approved within the near future work best in subjects with strong type 2 signatures. Available biomarkers and observable characteristics do not enable clinicians to recognize specific endotypes, but rather subphenotypes or overlapping endotypes. The goal of identifying the optimal patient for a specific therapy remains elusive, but worthy of pursuit. In the interim, the availability of an increasing number of treatment options allows the clinician to help most of his or her patients.

Novel Biological Therapies for Severe Asthma Endotypes

Severe asthma comprises several heterogeneous phenotypes, underpinned by complex pathomechanisms known as endotypes. The latter are driven by intercellular networks mediated by molecular components which can be targeted by specific monoclonal antibodies. With regard to the biological treatments of either allergic or non-allergic eosinophilic type 2 asthma, currently available antibodies are directed against immunoglobulins E (IgE), interleukin-5 (IL-5) and its receptor, the receptors of interleukins-4 (IL-4) and 13 (IL-13), as well as thymic stromal lymphopoietin (TSLP) and other alarmins. Among these therapeutic strategies, the best choice should be made according to the phenotypic/endotypic features of each patient with severe asthma, who can thus respond with significant clinical and functional improvements. Conversely, very poor options so far characterize the experimental pipelines referring to the perspective biological management of non-type 2 severe asthma, which thereby needs to be the focus of future thorough research.

Clinical Remission in Severe Asthma: A Pooled Post Hoc Analysis of the Patient Journey with Benralizumab

Introduction

Consensus definitions for clinical remission and super-response were recently established for severe asthma. Benralizumab is an interleukin-5 (IL-5) receptor α-directed monoclonal antibody for severe, uncontrolled asthma; efficacy and safety were demonstrated in previous pivotal phase 3 trials (SIROCCO, CALIMA, ZONDA). This analysis applied a composite remission definition to characterize individual responses to benralizumab after 6 and 12 months.

Methods

In previous phase 3 studies, eligible patients were those with severe, uncontrolled asthma receiving medium- or high-dosage inhaled corticosteroids plus long-acting β₂-agonists. This post hoc analysis included patients randomized to the approved benralizumab dose and not receiving oral corticosteroids (OCS) at baseline (SIROCCO/CALIMA) or OCS ≤ 12.5 mg per day (ZONDA). Individual remission components were zero exacerbations; zero OCS use; Asthma Control Questionnaire-6 (ACQ-6) score < 1.5 or ≤ 0.75; and pre-bronchodilator forced expiratory volume in 1 s (FEV₁) increase ≥ 100 mL; clinical remission incorporated zero exacerbations, zero OCS use, ACQ-6 score ≤ 0.75, and pre-bronchodilator FEV₁ increase ≥ 100 mL after 6 or 12 months.

Results

Overall, 609 patients (N = 301 and N = 308) and 586 patients (N = 293 and N = 293) receiving benralizumab in SIROCCO and CALIMA were included at 6 and 12 months, respectively; 40 ZONDA patients were included after 6 months. In SIROCCO/CALIMA, similar to 6-month findings,  approx. 83% and approx. 49% receiving benralizumab, and 77% and 37% on placebo achieved ≥ 2 and ≥ 3 remission components after 12 months; 14.5% (85/586) on benralizumab and 7.7% (48/620) on placebo achieved clinical remission at 12 months. Among ZONDA patients, 75% and approx. 48% on benralizumab and 35% and 20% on placebo achieved ≥ 2 and ≥ 3 remission components at 6 months, respectively; 22.5% (9/40) on benralizumab and 7.5% on placebo achieved clinical remission.

Conclusions

This analysis demonstrates clinical remission is achievable by targeting the underlying drivers of inflammation. Precision medicines can help shift treatment paradigms toward treat-to-target, with clinical remission as the ultimate therapeutic goal in severe asthma.

Clinical trial registration

SIROCCO (NCT01928771); CALIMA (NCT01914757); ZONDA (NCT02075255).

Steroid-induced fibroblast growth factors drive an epithelial-mesenchymal inflammatory axis in severe asthma

Asthma and inflammatory airway diseases restrict airflow in the lung, compromising gas exchange and lung function. Inhaled corticosteroids (ICSs) can reduce inflammation, control symptoms, and improve lung function; however, a growing number of patients with severe asthma do not benefit from ICS. Using bronchial airway epithelial brushings from patients with severe asthma or primary human cells, we delineated a corticosteroid-driven fibroblast growth factor (FGF)-dependent inflammatory axis, with FGF-responsive fibroblasts promoting downstream granulocyte colony-stimulating factor (G-CSF) production, hyaluronan secretion, and neutrophilic inflammation. Allergen challenge studies in mice demonstrate that the ICS, fluticasone propionate, inhibited type 2-driven eosinophilia but induced a concomitant increase in FGFs, G-CSF, hyaluronan, and neutrophil infiltration. We developed a model of steroid-induced neutrophilic inflammation mediated, in part, by induction of an FGF-dependent epithelial-mesenchymal axis, which may explain why some individuals do not benefit from ICS. In further proof-of-concept experiments, we found that combination therapy with pan-FGF receptor inhibitors and corticosteroids prevented both eosinophilic and steroid-induced neutrophilic inflammation. Together, these results establish FGFs as therapeutic targets for severe asthma patients who do not benefit from ICS.

Therapeutic Potential for Intractable Asthma by Targeting L-Type Amino Acid Transporter 1

Bronchial asthma is a chronic disease characterized by airway inflammation, obstruction, and hyperresponsiveness. CD4⁺ T cells, particularly T helper (Th) 2 cells, and their specific cytokines are important mediators in asthma pathogenesis. However, it has been established that Th subsets, other than Th2, as well as various cell types, including innate lymphoid cells (ILCs), significantly contribute to the development of allergic inflammation. These cells require facilitated amino acid uptake to ensure their full function upon activation. Emerging studies have suggested the potential of pharmacological inhibition of amino acid transporters to inhibit T cell activation and the application of this strategy for treating immunological and inflammatory disorders. In the present review, we explore the possibility of targeting L-type amino acid transporter (LAT) as a novel therapeutic approach for bronchial asthma, including its steroid-resistant endotypes.

What we know and still ignore on COVID-19 immune pathogenesis and a proposal based on the experience of allergic disorders

The coronavirus disease 2019 (COVID-19) pandemic started in March 2020 and caused over 5 million confirmed deaths worldwide as far August 2021. We have been recently overwhelmed by a wide literature on how the immune system recognizes severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and contributes to COVID-19 pathogenesis. Although originally considered a respiratory viral disease, COVID-19 is now recognized as a far more complex, multi-organ-, immuno-mediated-, and mostly heterogeneous disorder. Though efficient innate and adaptive immunity may control infection, when the patient fails to mount an adequate immune response at the start, or in advanced disease, a high innate-induced inflammation can lead to different clinical outcomes through heterogeneous compensatory mechanisms. The variability of viral load and persistence, the genetic alterations of virus-driven receptors/signaling pathways and the plasticity of innate and adaptive responses may all account for the extreme heterogeneity of pathogenesis and clinical patterns. As recently applied to some inflammatory disorders as asthma, rhinosinusitis with polyposis, and atopic dermatitis, herein we suggest defining different endo-types and the related phenotypes along COVID-19. Patients should be stratified for evolving symptoms and tightly monitored for surrogate biomarkers of innate and adaptive immunity. This would allow to preventively identify each endo-type (and its related phenotype) and to treat patients precisely with agents targeting pathogenic mechanisms.

Association of increased basic salivary proline-rich protein 1 levels in induced sputum with type 2-high asthma

BACKGROUND

The aim of this study is to reveal whether basic salivary proline-rich protein BstNI subfamily 1 (PRB1) may be used as a diagnostic biomarker for type 2-high asthma.

METHODS

PRB1 protein levels in the induced sputum of 67 subjects with asthma and 27 controls were determined by an enzyme-linked immunosorbent assay. Correlation analyses between PRB1 in the induced sputum and airway inflammatory indicators were also performed.

RESULTS

PRB1 protein levels were significantly upregulated in the induced sputum of asthmatic patients (p =0.0098) and correlated with clinical eosinophil-related indicators and type 2 airway inflammation. These results indicate that PRB1 is a promising biomarker for type 2-high asthma.

CONCLUSIONS

The expression of PRB1 in induced sputum is a potential biomarker for type 2-high asthma. The results of this study present new insights into the diagnosis and treatment of asthma.

Asthma with Fixed Airflow Obstruction: From Fixed to Personalized Approach

Asthma is generally characterized by variable symptoms such as dyspnea and wheezing and variable airflow obstruction. This review focuses on a subset of patients suffering from asthma with persistent airflow limitation that is not fully reversible (asthma with fixed airflow obstruction, FAO). The pathophysiology, the risk factors and the clinical outcomes associated with FAO are presented, as well as the distinct clinical entity of severe asthma and its inflammatory subtypes (T2 and non-T2). The current strategies for the treatment of these endotypes and treatment of the distinct Asthma/COPD overlap (ACO) phenotype are described. Management and medical interventions in FAO and/or ACO patients demand a holistic approach, which is not yet clearly established in guidelines worldwide. Finally, a treatment algorithm that includes FAO/ACO management based on pharmacological and non-pharmacological treatment, guideline-based management for specific co-morbidities, and modification of the risk factors is proposed.

Positionspapier: Empfehlungen zur Anwendung von Mepolizumab bei chronischer Rhinosinusitis mit Polyposis nasi (CRSwNP) im deutschen Gesundheitssystem – Empfehlungen des Ärzteverbandes Deutscher Allergologen (AeDA) und der AGs Klinische Immunologie, Allergologie und Umweltmedizin und Rhinologie und Rhinochirurgie der Deutschen Gesellschaft für HNO-Heilkunde, Kopf- und Hals-Chirurgie (DGHNO-KHC)

BACKGROUND

 Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial inflammatory disease of the paranasal sinus mucosa with eosinophilic inflammation as the most common endotype. The anti-IL5 antibody mepolizumab was approved for the treatment of severe CRSwNP in the EU in November 2021.

METHODS

 A literature search was performed to analyze the immunology of CRSwNP and determine the available evidence by searching Medline, Pubmed, and the German national and international trial and guideline registries and the Cochrane Library. Human studies published in the period up to and including 12/2021 that investigated the effect of mepolizumab in CRSwNP were considered.

RESULTS

 Based on the international literature and previous experience, recommendations for the use of mepolizumab in CRSwNP in the German health care system are given by an expert panel on the basis of a documentation form.

CONCLUSIONS

 Understanding about the immunological basis of CRSwNP opens new non-surgical therapeutic approaches with biologics for patients with severe courses. Mepolizumab is approved since November 2021 for add-on therapy with intranasal corticosteroids for the treatment of adult patients with severe CRSwNP who cannot be adequately controlled with systemic corticosteroids and/or surgical intervention.

STOP: an open label crossover trial to study ICS withdrawal in patients with a combination of obesity and low-inflammatory asthma and evaluate its effect on asthma control and quality of life

Background

Asthma patients with obesity often have a high disease burden, despite the use of high-dose inhaled corticosteroids (ICS). In contrast to asthmatics with normal weight, the efficacy of ICS in patients with obesity and asthma is often relatively low. Meanwhile, patients do suffer from side effects, such as weight gain, development of diabetes, cataract, or high blood pressure. The relatively poor response to ICS might be explained by the low prevalence of type 2 inflammatory patterns (T2-low) in patients with asthma and obesity. T2-low inflammation is characterized by low eosinophilic count, low Fractional exhaled NO (FeNO), no clinically allergy-driven asthma, and no need for maintenance oral corticosteroids (OCS). We aim to study whether ICS can be safely withdrawn in patients with T2-low asthma and obesity while maintaining an equal level of asthma control. Secondary outcomes focus on the prevalence of ‘false-negative’ T2-low phenotypes (i.e. T2-hidden) and the effect of ICS withdrawal on parameters of the metabolic syndrome. This study will lead to a better understanding of this poorly understood subgroup and might find new treatable traits.

Methods

The STOP trial is an investigator-initiated, multicenter, non-inferiority, open-label, crossover study aiming to assess whether ICS can be safely withdrawn in adults aged 17–75 years with T2-low asthma and obesity (body mass index (BMI) ≥ 30 kg/m2). Patients will be randomly divided into two arms (both n = 60). One arm will start with fixed-dose ICS (control group) and one arm will taper and subsequently stop ICS (intervention group). Patients in the intervention group will remain ICS naïve for ten weeks. After a washout of 4 weeks, patients will crossover to the other study arm. The crossover study takes 36 weeks to complete. Patients will be asked to participate in the extension study, to investigate the long-term metabolic benefits of ICS withdrawal.

Discussion

This study yields valuable data on ICS tapering in patients with T2-low asthma and obesity. It informs future guidelines and committees on corticosteroid-sparing algorithms in these patients.

Trial registration Netherlands Trial Register, NL8759, registered 2020–07-06, https://www.trialregister.nl/trial/8759.

Protocol version and date: version 2.1, 20 November 2020.

Association of sudden sensorineural hearing loss with asthma: a longitudinal follow-up study using a national sample cohort

OBJECTIVE

To investigate the risk of sudden sensorineural hearing loss (SSNHL) in asthma patients.

DESIGN

A longitudinal follow-up study using a retrospective cohort SETTING: The 2002-2013 Korean National Health Insurance Service-Health Screening Cohort PARTICIPANTS AND INTERVENTIONS: The ≥40 years old Korean population were enrolled. The asthma patients were 1:1 matched with the control group for age, sex, income and region of residence.

MAIN OUTCOME MEASURE

The occurrence of SSNHL was followed in both asthma and control groups. The stratified Cox proportional hazard model was used. Age, sex, income and region of residence were stratified, and Charlson Comorbidity Index scores, obesity, smoking, alcohol consumption and atopic dermatitis histories were adjusted. Subgroup analysis was performed according to age, sex, obesity, smoking and alcohol consumption.

RESULTS

The results showed that 1.0% (877/90 564) of the asthma group and 0.8% (706/90,564) of the control group exhibited SSNHL (p<0.001). The asthma group demonstrated a higher HR for SSNHL than the control group (adjusted HR 1.23, 95% CI 1.11 to 1.36, p<0.001). According to age and sex, the female subgroup showed elevated HRs for SSNHL in asthma patients. Both the non-smoker and current smoker groups demonstrated higher HRs for SSNHL in asthma patients than in controls. According to alcohol consumption or obesity, the <1 time a week alcohol consumption group and normal weight and severe obesity groups showed higher HRs for SSNHL in asthma patients than in the controls.

CONCLUSIONS

Adult asthma patients had a higher risk of SSNHL than the control participants matched for demographic and socioeconomic factors.

Reflux-related symptoms reflect poor asthma control and the presence of airway neuronal dysfunction

BACKGROUND

Gastroesophageal reflux may be associated with the worsening of asthma by increasing cough reflex sensitivity. Hull Airway Reflux Questionnaire (HARQ) consists of 14 prevalent reflux-related symptoms. It may be useful in predicting the presence of cough reflex hypersensitivity in asthma.

METHODS

From August 2018 to July 2020, 266 asthmatic patients completed the HARQ. They underwent blood analysis, spirometry, fraction of exhaled nitric oxide (FeNO) measurement, and the capsaicin cough challenge test. Patients were considered to have reflux-related symptoms if their HARQ scores were 13 points or higher. We evaluated the association between reflux-related symptoms and clinical asthma outcomes. Finally, we performed a multivariate analysis to determine the clinical significance of the HARQ for asthma. This study was registered in the University Hospital Medical Information Network (UMIN000040732).

RESULTS

The mean HARQ scores were 13.1 (standard deviation 12.0). Patients in the high HARQ scores group (HARQ ≥13, n = 105) showed a lower prevalence of atopic predisposition, lower levels of FeNO, heightened capsaicin cough reflex sensitivity, poorer asthma control, and more frequent admissions due to asthma than those in the low HARQ groups (all p values < 0.05). The HARQ was useful in selecting patients with poor controlled asthma and those with severe cough when the cut-off value was set at 13. Multivariate analysis revealed that heightened capsaicin cough reflex sensitivity affected reflux-related symptoms, as well as lower levels of FeNO and younger age.

CONCLUSIONS

Higher HARQ scores (≥13) may be useful in predicting not only poor asthma condition but also the presence of airway neuronal dysfunction in patients with asthma to some extent.

Stratified approaches for using biomarkers in phenotyping for the management of severe asthma in India

Various respiratory societies including the Global Initiative for Asthma (GINA), European Respiratory Society (ERS) and American Thoracic Society (ATS) define severe asthma as asthma that requires or remains uncontrolled despite treatment with systemic corticosteroids or high-dose inhaled corticosteroids plus another controller such as long acting beta agonist. The management of asthma as an entity is not straightforward due to inter-individual variability in assessment parameters. With the advent of science, targeted therapies are on the emergence for management of severe asthma. A biomarker can be used as a surrogate to phenotype a patient as well as to measure the response to therapy with any drug. Biomarkers have been critical for studies of disease pathogenesis and the development of new therapies in severe asthma. From a resource constraint perspective like countries in India, it is imperative to use biomarkers that are easily available are affordable cost. Choosing an ideal biomarkers is also important from a perspective of choosing a particular therapy. The cost associated with the biologicals is high and it is imperative to gauge the treatment effectiveness with the therapy at the earliest considering the out of pocket spends of the patients.

[Possible therapeutic use of L-type amino acid transporter 1 (LAT1)-specific inhibitor for intractable asthma treatment]

Bronchial asthma (asthma) is characterized by chronic airway inflammation, reversible obstruction, and hyperresponsive conditions. Although most asthma patients have been becoming controllable by virtue of inhaled corticosteroid (ICS), substantial number of patients still do not respond to the steroid-based therapy. Mast cells, eosinophils, and helper T (Th) 2 cells have been considered as key players in asthma pathogenesis. However, emerging studies have revealed that Th subsets other than Th2, as well as various other immune cells, significantly contribute to the development of steroid-resistant intractable asthma. T cells and other inflammatory cells require incorporating a large amount of nutrients such as amino acids and glucose to exhibit their full function following activation. Based on this remarkable character, it has recently been suggested that the pharmacological inhibition of amino acid transporters is promising for treating immunological and inflammatory disorders through the suppression of inflammatory cell activation. In this review, we explore the possible management of intractable asthma by developing a selective inhibitor for L-type amino acid transporter (LAT) 1.

Switch from Omalizumab to Benralizumab in Allergic Patients with Severe Eosinophilic Asthma: A Real-Life Experience from Southern Italy

Background. The wide availability of monoclonal antibodies for the add-on therapy of severe asthma currently allows for the personalization of biologic treatment by selecting the most appropriate drug for each patient. However, subjects with overlapping allergic and eosinophilic phenotypes can be often eligible to more than one biologic, so that the first pharmacologic choice can be quite challenging for clinicians. Within such a context, the aim of our real-life investigation was to verify whether allergic patients with severe eosinophilic asthma, not adequately controlled by an initial biologic treatment with omalizumab, could experience better therapeutic results from a pharmacologic shift to benralizumab. Patients and methods. Twenty allergic patients with severe eosinophilic asthma, unsuccessfully treated with omalizumab and then switched to benralizumab, were assessed for at least 1 year in order to detect eventual changes in disease exacerbations, symptom control, oral corticosteroid intake, lung function, and blood eosinophils. Results. In comparison to the previous omalizumab therapy, after 1 year of treatment with benralizumab our patients experienced significant improvements in asthma exacerbation rate (p < 0.01), rescue medication need (p < 0.001), asthma control test (ACT) score (p < 0.05), forced expiratory volume in the first second (FEV₁) (p < 0.05), and blood eosinophil count (p < 0.0001). Furthermore, with respect to the end of omalizumab treatment, the score of sino-nasal outcome test-22 (SNOT-22) significantly decreased after therapy with benralizumab (p < 0.05). Conclusion. The results of this real-life study suggest that the pharmacologic shift from omalizumab to benralizumab can be a valuable therapeutic approach for allergic patients with severe eosinophilic asthma, not adequately controlled by anti-IgE treatment.

Advances and highlights in biomarkers of allergic diseases

During the past years, there has been a global outbreak of allergic diseases, presenting a considerable medical and socioeconomical burden. A large fraction of allergic diseases is characterized by a type 2 immune response involving Th2 cells, type 2 innate lymphoid cells, eosinophils, mast cells, and M2 macrophages. Biomarkers are valuable parameters for precision medicine as they provide information on the disease endotypes, clusters, precision diagnoses, identification of therapeutic targets, and monitoring of treatment efficacies. The availability of powerful omics technologies, together with integrated data analysis and network‐based approaches can help the identification of clinically useful biomarkers. These biomarkers need to be accurately quantified using robust and reproducible methods, such as reliable and point‐of‐care systems. Ideally, samples should be collected using quick, cost‐efficient and noninvasive methods. In recent years, a plethora of research has been directed toward finding novel biomarkers of allergic diseases. Promising biomarkers of type 2 allergic diseases include sputum eosinophils, serum periostin and exhaled nitric oxide. Several other biomarkers, such as pro‐inflammatory mediators, miRNAs, eicosanoid molecules, epithelial barrier integrity, and microbiota changes are useful for diagnosis and monitoring of allergic diseases and can be quantified in serum, body fluids and exhaled air. Herein, we review recent studies on biomarkers for the diagnosis and treatment of asthma, chronic urticaria, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food allergies, anaphylaxis, drug hypersensitivity and allergen immunotherapy. In addition, we discuss COVID‐19 and allergic diseases within the perspective of biomarkers and recommendations on the management of allergic and asthmatic patients during the COVID‐19 pandemic.

Characteristics of tissue-resident ILCs and their potential as therapeutic targets in mucosal and skin inflammatory diseases

Discovery of innate lymphoid cells (ILCs), which are non-T and non-B lymphocytes that have no antigen-specific receptors, changed the classical concept of the mechanism of allergy, which had been explained mainly as antigen-specific acquired immunity based on IgE and Th2 cells. The discovery led to dramatic improvement in our understanding of the mechanism of non-IgE-mediated allergic inflammation. Numerous studies conducted in the past decade have elucidated the characteristics of each ILC subset in various organs and tissues and their ontogeny. We now know that each ILC subset exhibits heterogeneity. Moreover, the functions and activating/suppressing factors of each ILC subset were found to differ among both organs and types of tissue. Therefore, in this review, we summarize our current knowledge of ILCs by focusing on the organ/tissue-specific features of each subset to understand their roles in various organs. We also discuss ILCs' involvement in human inflammatory diseases in various organs and potential therapeutic/preventive strategies that target ILCs.

Highlights in the advances of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex upper airway inflammatory disease with a broad spectrum of clinical variants. As our understanding of the disease pathophysiology evolves, so too does our philosophy towards the approach and management of CRS. Endotyping is gaining favour over phenotype-based classifications, owing to its potential in prognosticating disease severity and delivering precision treatment. Endotyping is especially useful in challenging CRS with nasal polyposis cases, for whom novel treatment options such as biologicals are now available. The latest European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS2020) reflects these changes with updated rhinosinusitis classifications and new integrated care pathways. With the coronavirus disease 2019 (COVID-19) pandemic, physicians and rhinologists have to balance the responsibility of managing their patients' upper airway while adequately protecting themselves from droplet and aerosol transmission. This review summarises the key updates from EPOS2020, endotype-based classification and biomarkers. The role of biologicals in CRS and the lessons we can draw from their use in severe asthma will be examined. Finally, the principles of CRS management during COVID-19 will also be discussed.

Short-Term Evaluation of Dupilumab Effects in Patients with Severe Asthma and Nasal Polyposis

Background

Having been approved for biological treatment of atopic dermatitis, dupilumab has also been recently licensed as add-on therapy for severe asthma and nasal polyposis. With regard to the latter diseases, few real-life clinical investigations have been carried out to date.

Objective

The primary end point of this single-center observational study was to evaluate in a real-life setting the short-term therapeutic effects of dupilumab in patients with severe asthma and nasal polyposis.

Methods

At baseline and after 4 weeks of add-on therapy with dupilumab, several clinical and functional parameters were assessed in 20 patients with severe asthma and nasal polyposis, including both allergic and nonallergic subjects.

Results

After 4 weeks of treatment with dupilumab, all patients experienced remarkable improvement in both severe asthma and nasal polyposis. In particular, asthma-control test and sinonasal outcome test 22 scores had significantly increased (p<0.0001) and decreased (p<0.0001), respectively. Oral corticosteroid intake got to zero within 4 weeks (p<0.0001). Moreover, in week 4, significant increases were detected with regard to both prebronchodilator forced expiratory volume in the first second (p<0.01) and forced vital capacity (FVC; p<0.05). At the same time point, dupilumab had significantly reduced residual volume (p<0.0001) and total lung capacity (p<0.001), whereas it had enhanced forced midexpiratory flow of 25%–75% FVC (p<0.01) and peak expiratory flow (p<0.01). After 4 weeks of treatment, dupilumab had also lowered levels of fractional exhaled nitric oxide (p<0.0001).

Conclusion

The results of this real-life study suggest that dupilumab can be utilized in both allergic and nonallergic patients with severe asthma and nasal polyposis as a valuable add-on biological therapy with rapid onset of action.

The inflammatory profile of exacerbations in patients with severe refractory eosinophilic asthma receiving mepolizumab (the MEX study): a prospective observational study

BACKGROUND

Clinical trials with mepolizumab, a humanised monoclonal antibody against interleukin-5, show a 50% reduction in severe asthma exacerbations in people with severe eosinophilic asthma. Exacerbations in patients treated with mepolizumab seem to be different to exacerbations in those given placebo, as patients treated with mepolizumab report fewer symptoms, have a lower sputum eosinophil count, and smaller fall in peak expiratory flow. We aimed to investigate the inflammatory phenotype and physiological characteristics of exacerbation events in patients with severe eosinophilic asthma who were treated with mepolizumab.

METHODS

This multicentre, prospective, observational cohort study was carried out at four UK specialist severe asthma centres. Participants were aged 18-80 years, with severe eosinophilic asthma (Global Initiative for Asthma steps 4 and 5), and were eligible for mepolizumab therapy. All participants received mepolizumab 100 mg subcutaneously every 4 weeks, had a scheduled study visit when stable on mepolizumab (≥3 months on treatment), and measured daily peak flow and completed symptoms diaries throughout the course of the study. Participants attended their study centre for unscheduled exacerbation assessment when symptoms worsened outside of their normal daily variation and before commencing rescue treatment. If a participant was unable to attend their study centre for exacerbation or had initiated rescue treatment before the study visit, clinical details of the missed exacerbation were collected by clinical staff. In this exploratory study, the endpoint was 100 clinical assessments at exacerbation completed across all sites for participants on mepolizumab before initiation of rescue treatment. Characteristics of those who had exacerbations on mepolizumab were compared with those who did not, peak flow and symptoms diaries were compared for assessed versus missed exacerbations, and exacerbation phenotypes defined by sputum eosinophil cell count were compared. The utility of fractional exhaled nitric oxide (FeNO) and C-reactive protein in determining exacerbation phenotype on mepolizumab treatment were also assessed. This study is registered with ClinicalTrials.gov, NCT03324230.

FINDINGS

Between Nov 30, 2017, and May 29, 2019, 145 participants were enrolled and treated with mepolizumab, five were excluded from the analysis. 172 exacerbations occurred, with 96 (56%) assessed before commencing rescue treatment. Compared with patients who did not exacerbate, patients who exacerbated had a higher exacerbation rate and more emergency department attendances in the year before commencing mepolizumab. The change in peak expiratory flow at nadir in the assessed exacerbation group was mean -40·5 L/min (SD 76·3) versus mean -37·0 L/min (93·0; p=0·84) in the missed exacerbation group, and there was no difference in reported symptom burden. When comparing exacerbations with a high sputum eosinophil count (≥2%; SEHIGH) with exacerbations with a low sputum eosinophil count (<2%; SELOW), the SEHIGH exacerbations were FeNO high (median difference 33 parts per billion [ppb; 95% CI 8 to 87]; p=0·0004), with lower FEV1 percent predicted (mean difference -15·9% [-27·0 to -4·8]; p=0·0075), lower FEV1 to forced vital capacity ratio (mean difference -10·3 [-17·0 to -3·6]; p=0·0043), and higher blood eosinophil counts (median difference 40 cells per μL [20 to 70]; p=0·0009). By contrast, SELOW exacerbations had higher C-reactive protein concentrations (median difference 12·7 mg/L [3·5 to 18·5]; p<0·0001), higher sputum neutrophil counts (median difference 52·7% [34·5 to 59·2]; p<0·0001), and were more likely to be treated with antibiotics (p=0·031). FeNO (≤20 or ≥50 ppb) was the most useful discriminator of inflammatory phenotype at exacerbation. The most common adverse event was hospital admission due to asthma exacerbation (17 [50%] of 34 events), none of the adverse events were study procedure related.

INTERPRETATION

Exacerbations on mepolizumab are two distinct entities, which can largely be differentiated using FeNO: non-eosinophilic events are driven by infection with a low FeNO and high C-reactive protein concentration, whereas eosinophilic exacerbations are FeNO high. The results of the MEX study challenge the routine use of oral corticosteroids for the treatment of all asthma exacerbation events on mepolizumab, as well as the switching of biological therapies for treatment failure without profiling the inflammatory phenotype of ongoing asthma exacerbations. The results highlight clinically available tools to enable profiling of these residual exacerbations in patients treated with mepolizumab.

FUNDING

UK Medical Research council.

Reduction/elimination of blood eosinophils in severe asthma: should there be a safety consideration?

INTRODUCTION

Eosinophils play a central role in the inflammation of asthma and are the target of new biologic treatments for patients with severe asthma. Biologics targeting the IL-5 pathway have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life, accompanied by reduced or even eliminated blood eosinophils. Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of these long-term therapies that reduce or eliminate them.

AREAS COVERED

In this review, we explore the current safety profile of biologics regarding the impact they may have on blood eosinophils, trying to answer the question about any safety consideration.

EXPERT OPINION

Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of long-term therapies that reduce or eliminate these blood cells.

Interactions between NCR+ILC3s and the Microbiome in the Airways Shape Asthma Severity

Asthma is a heterogeneous disease whose development is shaped by a variety of environmental and genetic factors. While several recent studies suggest that microbial dysbiosis in the gut may promote asthma, little is known about the relationship between the recently discovered lung microbiome and asthma. Innate lymphoid cells (ILCs) have also been shown recently to participate in asthma. To investigate the relationship between the lung microbiome, ILCs, and asthma, we recruited 23 healthy controls (HC), 42 patients with non-severe asthma, and 32 patients with severe asthma. Flow cytometry analysis showed severe asthma associated with fewer natural cytotoxicity receptor (NCR)+ILC3s in the lung. Similar changes in other ILC subsets, macrophages, and monocytes were not observed. The asthma patients did not differ from the HC in terms of the alpha and beta-diversity of the lung and gut microbiomes. However, lung function correlated positively with both NCR+ILC3 frequencies and microbial diversity in the lung. Sputum NCR+ILC3 frequencies correlated positively with lung microbiome diversity in the HC, but this relationship was inversed in severe asthma. Together, these data suggest that airway NCR+ILC3s may contribute to a healthy commensal diversity and normal lung function.

Tezepelumab: A Potential New Biological Therapy for Severe Refractory Asthma

Thymic stromal lymphopoietin (TSLP) is an innate cytokine, belonging to the group of alarmins, which plays a key pathogenic role in asthma by acting as an upstream activator of cellular and molecular pathways leading to type 2 (T2-high) airway inflammation. Released from airway epithelial cells upon tissue damage induced by several noxious agents including allergens, viruses, bacteria, and airborne pollutants, TSLP activates dendritic cells and group 2 innate lymphoid cells involved in the pathobiology of T2-high asthma. Tezepelumab is a fully human monoclonal antibody that binds to TSLP, thereby preventing its interaction with the TSLP receptor complex. Preliminary results of randomized clinical trials suggest that tezepelumab is characterized by a good safety and efficacy profile in patients with severe, uncontrolled asthma.

Therapeutic Effects of Benralizumab Assessed in Patients with Severe Eosinophilic Asthma: Real-Life Evaluation Correlated with Allergic and Non-Allergic Phenotype Expression

Background

Benralizumab can be utilized as add-on biological treatment of severe eosinophilic asthma. However, so far only a few real-life studies have been published with regard to the use of this anti-IL-5 receptor humanized monoclonal antibody.

Objective

The primary aim of this multicenter observational investigation has been to assess the therapeutic effects of benralizumab in patients with severe uncontrolled, corticosteroid refractory eosinophilic asthma. The secondary objective was to evaluate the efficacy of benralizumab with regard to positive or negative skin prick test (SPT).

Methods

Clinical, functional, and laboratory parameters were evaluated in order to verify the therapeutic actions of benralizumab in atopic and non atopic subjects with difficult-to-treat eosinophilic asthma. Moreover, a comparative evaluation was carried out in relation to the presence or absence of SPT positivity.

Results

After 6 months of add-on biological therapy with benralizumab, our 111 patients experienced a marked improvement of their severe eosinophilic asthma, expressed by significant changes in asthma exacerbation rate, prednisone intake, daily use of short-acting β₂-adrenergic agonists (SABA), asthma control test (ACT) score, asthma quality of life questionnaire (AQLQ) score (56 patients), forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), blood eosinophil count, blood basophil count (59 patients), and fractional exhaled nitric oxide (FeNO) levels (39 patients). In addition, significantly more effective outcomes were detected in patients with positive SPT, when compared to subjects with negative SPT, only in regard to asthma exacerbation number, ACT score, and daily SABA utilization. No significant correlation was found between serum IgE concentrations and each of all measured parameters.

Conclusion and Clinical Relevance

Taken together, the results of this real-world study indicate that in both allergic and non-allergic subjects benralizumab can be used as a valuable pharmacotherapeutic option for add-on biological therapy of severe eosinophilic asthma, regardless of SPT positivity or negativity.

The cost-effectiveness of azithromycin in reducing exacerbations in uncontrolled asthma

Add-on azithromycin (AZM) results in a significant reduction in exacerbations among adults with persistent uncontrolled asthma. The aim of this study was to assess the cost-effectiveness of add-on AZM in terms of healthcare and societal costs.The AMAZES trial randomly assigned 420 participants to AZM or placebo. Healthcare use and asthma exacerbations were measured during the treatment period. Healthcare use included all prescribed medicine and healthcare contacts. Costs of antimicrobial resistance (AMR) were estimated based on overall consumption and published estimates of costs. The value of an avoided exacerbation was based on published references. Differences in cost between the two groups were related to differences in exacerbations in a series of net monetary benefit estimates. Societal costs included lost productivity, over the counter medicines, steroid induced morbidity and AMR costs.Add-on AZM resulted in a reduction in healthcare costs (mean (95% CI)) including nights in hospital (AUD 433.70 (AUD 48.59-818.81) or EUR 260.22 (EUR 29.15-491.29)), unplanned healthcare visits (AUD 20.25 (AUD 5.23-35.27) or EUR 12.15 (EUR 3.14-21.16)), antibiotic costs (AUD 14.88 (AUD 7.55-22.21) or EUR 8.93 (EUR 4.53-13.33)) and oral corticosteroid costs (AUD 4.73 (AUD 0.82-8.64) or EUR 2.84 (EUR 0.49-5.18)); all p<0.05. Overall healthcare and societal costs were lower (AUD 77.30 (EUR 46.38) and AUD 256.22 (EUR 153.73) respectively) albeit not statistically significant. The net monetary benefit of add-on AZM was estimated to be AUD 2072.30 (95% CI AUD 1348.55-2805.23) or (EUR 1243.38 (EUR 809.13-1683.14) assuming a willingness to pay per exacerbation avoided of AUD 2651 (EUR 1590.60). Irrespective of the sensitivity analysis applied, the net monetary benefit for total, moderate and severe exacerbations remained positive and significant.Add-on AZM therapy in poorly controlled asthma was a cost-effective therapy. Costs associated with AMR did not influence estimated cost-effectiveness.

Biologics in severe asthma

Asthma is a chronic airway disease consisting of usually variable airflow limitation and bronchial hyperresponsiveness. Many different phenotypes characterize the clinical expression of asthma, determined by heterogeneous inflammatory patterns driven by distinct cellular and molecular mechanisms known as endotypes. Inside the complex framework of asthma pathobiology, several molecules such as immunoglobulins E (IgE), pro-inflammatory cytokines and their receptors can be targeted by present and future biological treatments of severe asthma. Within this context, already registered monoclonal antibodies including omalizumab, mepolizumab, reslizumab, benralizumab and dupilumab may interfere at various levels with the pathogenic pathways responsible for type-2 airway inflammation. In particular, these drugs target IgE (omalizumab), IL-5 (mepolizumab and reslizumab), IL-5 receptor (benralizumab) and IL-4/IL-13 receptors (dupilumab), respectively. Moreover, other biological therapies are under evaluation in pre-marketing trials, mainly aimed to assess the efficacy and safety of monoclonal antibodies directed against innate cytokines such as IL-33 and thymic stromal lymphopoietin (TSLP). Among current and perspective therapeutic approaches, clinicians can choose phenotype/endotype-driven tailored treatments, able to pursue an effective control of difficult to treat type-2 asthma.

IL-33 and Superantigenic Activation of Human Lung Mast Cells Induce the Release of Angiogenic and Lymphangiogenic Factors

Human lung mast cells (HLMCs) express the high-affinity receptor FcεRI for IgE and are strategically located in different compartments of human lung, where they play a role in several inflammatory disorders and cancer. Immunoglobulin superantigens (e.g., protein A of Staphylococcus aureus and protein L of Peptostreptococcus magnus) bind to the variable regions of either the heavy (V_H3) or light chain (κ) of IgE. IL-33 is a cytokine expressed by epithelial cells that exerts pleiotropic functions in the lung. The present study investigated whether immunoglobulin superantigens protein A and protein L and IL-33 caused the release of inflammatory (histamine), angiogenic (VEGF-A) and lymphangiogenic (VEGF-C) factors from HLMCs. The results show that protein A and protein L induced the rapid (30 min) release of preformed histamine from HLMCs. By contrast, IL-33 did not induce the release of histamine from lung mast cells. Prolonged incubation (12 h) of HLMCs with superantigens and IL-33 induced the release of VEGF-A and VEGF-C. Preincubation with IL-33 potentiated the superantigenic release of histamine, angiogenic and lymphangiogenic factors from HLMCs. Our results suggest that IL-33 might enhance the inflammatory, angiogenic and lymphangiogenic activities of lung mast cells in pulmonary disorders.

EAACI Biologicals Guidelines-Recommendations for severe asthma

Severe asthma imposes a significant burden on patients, families and healthcare systems. Management is difficult, due to disease heterogeneity, co-morbidities, complexity in care pathways and differences between national or regional healthcare systems. Better understanding of the mechanisms has enabled a stratified approach to the management of severe asthma, supporting the use of targeted treatments with biologicals. However, there are still many issues that require further clarification. These include selection of a certain biological (as they all target overlapping disease phenotypes), the definition of response, strategies to enhance the responder rate, the duration of treatment and its regimen (in the clinic or home-based) and its cost-effectiveness. The EAACI Guidelines on the use of biologicals in severe asthma follow the GRADE approach in formulating recommendations for each biological and each outcome. In addition, a management algorithm for the use of biologicals in the clinic is proposed, together with future approaches and research priorities.