Personalized medicine with biologics for severe type 2 asthma: current status and future prospects

Geographic and economic influences on benralizumab prescribing for severe asthma in Japan

Benralizumab, a monoclonal antibody targeting IL-5 receptors, reduces exacerbations and oral corticosteroid requirements for severe, uncontrolled eosinophilic asthma. In Japan, geographic disparities in asthma outcomes suggest differential prescribing and access. This study aimed to quantify regional prescribing variations for benralizumab nationwide. Using Japan's National Database (NDB) of insurance claims (2009-2019), benralizumab standardized claim ratios (SCRs) were calculated for 47 prefectures. Correlations between SCRs and other biologics' SCRs, economic variables like average income, and physician densities were evaluated through univariate analysis and multivariate regressions. Income-related barriers to optimal prescribing were examined. Wide variation emerged in benralizumab SCRs, from 40.1 to 184.2 across prefectures. SCRs strongly correlated with omalizumab (r = 0.61, p < 0.00001) and mepolizumab (r = 0.43, p = 0.0024). Average monthly income also positively correlated with benralizumab SCRs (r = 0.45, p = 0.0016), whereas lifestyle factors were insignificant. Respiratory specialist density modestly correlated with SCRs (r = 0.29, p = 0.047). In multivariate regressions, average income remained the most robust predictor (B = 0.74, p = 0.022). Benralizumab SCRs strongly associate with income metrics more than healthcare infrastructure/population factors. Many regions show low SCRs, constituting apparent prescribing gaps. Access barriers for advanced asthma therapies remain inequitable among Japan's income strata. Addressing affordability alongside specialist allocation can achieve better prescribing quality and asthma outcomes.

Asthma Phenotypes in the Era of Personalized Medicine

Asthma is a widespread disease affecting approximately 300-million people globally. This condition leads to significant morbidity, mortality, and economic strain worldwide. Recent clinical and laboratory research advancements have illuminated the immunological factors contributing to asthma. As of now, asthma is understood to be a heterogeneous disease. Personalized medicine involves categorizing asthma by its endotypes, linking observable characteristics to specific immunological mechanisms. Identifying these endotypic mechanisms is paramount in accurately profiling patients and tailoring therapeutic approaches using innovative biological agents targeting distinct immune pathways. This article presents a synopsis of the key immunological mechanisms implicated in the pathogenesis and manifestation of the disease's phenotypic traits and individualized treatments for severe asthma subtypes.

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.

The combination of machine learning and untargeted metabolomics identifies the lipid metabolism -related gene CH25H as a potential biomarker in asthma

BACKGROUND

Lipids, significant signaling molecules, regulate a multitude of cellular responses and biological pathways in asthma which are closely associated with disease onset and progression. However, the characteristic lipid genes and metabolites in asthma remain to be explored. It is also necessary to further investigate the role of lipid molecules in asthma based on high-throughput data.

OBJECTIVE

To explore the biomarkers and molecular mechanisms associated with lipid metabolism in asthma.

METHODS

In this study, we selected three mouse-derived datasets and one human dataset (GSE41665, GSE41667, GSE3184 and GSE67472) from the GEO database. Five machine learning algorithms, LASSO, SVM-RFE, Boruta, XGBoost and RF, were used to identify core gene. Additionally, we used non-negative matrix breakdown (NMF) clustering to identify two lipid molecular subgroups and constructed a lipid metabolism score by principal component analysis (PCA) to differentiate the subtypes. Finally, Western blot confirmed the altered expression levels of core genes in OVA (ovalbumin) and HDM+LPS (house dust mite+lipopolysaccharide) stimulated and challenged BALB/c mice, respectively. Results of non-targeted metabolomics revealed multiple differentially expressed metabolites in the plasma of OVA-induced asthmatic mice.

RESULTS

Cholesterol 25-hydroxylase (CH25H) was finally localized as a core lipid metabolism gene in asthma and was verified to be highly expressed in two mouse models of asthma. Five-gene lipid metabolism constructed from CYP2E1, CH25H, PTGES, ALOX15 and ME1 was able to distinguish the subtypes effectively. The results of non-targeted metabolomics showed that most of the aberrantly expressed metabolites in the plasma of asthmatic mice were lipids, such as LPC 16:0, LPC 18:1 and LPA 18:1.

CONCLUSION

Our findings imply that the lipid-related gene CH25H may be a useful biomarker in the diagnosis of asthma.

The Role and Clinical Relevance of Osteopontin in Allergic Airway Diseases

The airway epithelium is exposed to numerous external irritants including infectious agents, environmental allergens, and atmospheric pollutants, releasing epithelial cytokines including thymic stromal lymphopoietin (TSLP), IL-33, and IL-25 and initiating downstream type 2 (IL-4, IL-13, and IL-5) and IgE-driven pathways. These pathways trigger the initiation and progression of allergic airway diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP), allergic rhinitis (AR), and allergic asthma. However, the use of biological agents that target downstream cytokines, such as IL-5, IL-4, and IL-13 receptors and IgE, might not be sufficient to manage some patients successfully. Instead of blocking downstream cytokines, targeting upstream epithelial cytokines has been proposed to address the complex immunologic networks associated with allergic airway diseases. Osteopontin (OPN), an extracellular matrix glyco-phosphoprotein, is a key mediator involved in Th1-related diseases, including systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Emerging evidence, including ours, indicates that epithelial-cell-derived OPN also plays an essential role in Th2-skewed airway diseases, including CRSwNP, AR, and allergic asthma involving the Th17 response. Therefore, we reviewed the current knowledge of epithelial-cell-derived OPN in the pathogenesis of three type-2-biased airway diseases and provided a direction for its future investigation and clinical relevance.

Dupilumab Efficacy in Patients with Uncontrolled Moderate-to-Severe Type 2 Asthma Regardless of Perennial Aeroallergen Sensitization

Purpose

Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukins-4/-13, key and central drivers of type 2 (T2) inflammation in multiple diseases. In phase 3 QUEST (NCT02414854), dupilumab vs placebo significantly reduced asthma exacerbation rates (AER) and improved pre-bronchodilator forced expiratory volume in 1 second (FEV₁) in patients with uncontrolled, moderate-to-severe asthma, with greater effects in patients with elevated T2 biomarkers (≥150 eosinophils/µL or fractional exhaled nitric oxide [FeNO] ≥25 parts per billion). Overall safety was consistent with the known dupilumab safety profile. This post hoc analysis assessed dupilumab efficacy in QUEST patients with T2 asthma with evidence of an allergic phenotype (baseline serum IgE ≥30 IU/mL and aeroallergen-specific IgE ≥0.35 IU/mL) by number of aeroallergen sensitizations: 1, 2, 3, or ≥4. Non-sensitized patients (serum total IgE <30 IU/mL without evidence of allergic phenotype) were also assessed.

Patients and Methods

Endpoints were annualized AER, change from baseline in pre-bronchodilator FEV₁ and asthma control (5-item Asthma Control Questionnaire [ACQ-5]), and FeNO and serum total IgE levels over the 52-week treatment period.

Results

In all subgroups by number of allergens sensitized, dupilumab vs placebo reduced AER by 35-67% and improved both pre-bronchodilator FEV₁ at Week 12 (least squares mean differences: 0.10-0.26 L across subgroups) and ACQ-5 score at Week 52 (-0.26 to -0.43). Dupilumab significantly reduced FeNO and total IgE levels at Week 52 compared with placebo. Similar results were observed in non-sensitized patients.

Conclusion

Dupilumab improved clinical outcomes and reduced biomarker levels in patients with uncontrolled, moderate-to-severe T2 asthma irrespective of allergen sensitization status or number.

Clinical Trial Registration

ClinicalTrials.gov Identifier: NCT02414854.

The Role of Staphylococcus aureus and Its Toxins in the Pathogenesis of Allergic Asthma

Bronchial asthma is one of the most common chronic diseases worldwide and affects more than 300 million patients. Allergic asthma affects the majority of asthmatic children as well as approximately 50% of adult asthmatics. It is characterized by a Th2-mediated immune response against aeroallergens. Many aspects of the overall pathophysiology are known, while the underlying mechanisms and predisposing factors remain largely elusive today. Over the last decade, respiratory colonization with Staphylococcus aureus (S. aureus), a Gram-positive facultative bacterial pathogen, came into focus as a risk factor for the development of atopic respiratory diseases. More than 30% of the world’s population is constantly colonized with S. aureus in their nasopharynx. This colonization is mostly asymptomatic, but in immunocompromised patients, it can lead to serious complications including pneumonia, sepsis, or even death. S. aureus is known for its ability to produce a wide range of proteins including toxins, serine-protease-like proteins, and protein A. In this review, we provide an overview of the current knowledge about the pathophysiology of allergic asthma and to what extent it can be affected by different toxins produced by S. aureus. Intensifying this knowledge might lead to new preventive strategies for atopic respiratory diseases.

Uncontrolled severe T2 asthma: Which biological to choose? A biomarker-based approach

In recent years, advances in knowledge of molecular mechanisms involved in asthma have changed uncontrolled severe asthma (USA) treatment, with the appearance of biological treatment. USA is a heterogeneous entity with different endotypes and phenotypes. Nowadays, the biological drugs approved with asthma indication are omalizumab, mepolizumab, reslizumab, benralizumab and dupilumab. Tezepelumab is approved by the Food and Drug Administration (FDA) in the United States and, recently, by the European Medicines Agency (EMA). All these biological drugs have shown their efficacy in clinical trials, especially in reducing exacerbations, improving asthma control, quality of life, pulmonary function, and withdrawing systemic corticosteroids or at least reducing their daily dose, with some differences between them. Except for mepolizumab and reslizumab, biological drugs have different targets and thus different therapeutic indications should be expected; however, in some patients, more than one drug could be indicated, making the election more difficult. Because there are no direct comparisons between biological drugs, some biomarkers are used to choose between them, but they are not unbeatable. In this article, an algorithm to choose the first biological drug in a specific patient is proposed based on different study results and patient' characteristics.

Dupilumab efficacy and safety in Latin American patients with uncontrolled, moderate-to-severe asthma: phase 3 LIBERTY ASTHMA QUEST study

Objective: While advances in asthma care have been made in Latin America, there is still a large unmet need in patients with uncontrolled asthma. This post hoc analysis of the QUEST study assessed safety and efficacy of dupilumab in the subgroup of patients enrolled in Latin American countries with a type 2 inflammatory asthma phenotype (blood eosinophils ≥150cells/µL or FeNO ≥25ppb).Methods: LIBERTY ASTHMA QUEST (NCT02414854) was a phase 3, multinational, randomized, double-blind, placebo-controlled study in patients with uncontrolled, moderate-to-severe asthma. Eligible patients ≥12 years of age were randomized in a 2:2:1:1 ratio to receive 52 weeks of add-on subcutaneous dupilumab 200 or 300mg every 2 weeks or matched-volume placebos. Pre-specified co-primary efficacy endpoints were the annualized rate of severe exacerbations during the treatment period and the change from baseline in pre-bronchodilator FEV₁ at treatment week 12. Asthma control, changes in asthma biomarker levels, and dupilumab safety were also evaluated.Results: 530 (27.9% of the overall QUEST population; dupilumab: 353, placebo: 177) Latin-American patients were recruited; 420 (79.2%) had a type 2 inflammatory asthma phenotype. Dupilumab vs placebo reduced the annualized rate of severe exacerbations by 52.7% (P < 0.001) and increased pre-bronchodilator FEV₁ at week 12 by 0.15L (P < 0.001), in the type 2 population. Safety was consistent with the known dupilumab safety profile.Conclusions: Consistent with the results in the overall population, dupilumab reduced the risk of severe asthma exacerbations and improved lung function in Latin American patients with uncontrolled, moderate-to-severe asthma and a type 2 phenotype.

Biologics in severe asthma: Outcomes in clinical trials-Similarities and differences

INTRODUCTION

Severe asthma is a heterogenous disease characterized by multiple phenotypes. Targeted biologic therapies have revolutionarily changed the management of severe asthma by affecting various clinical outcomes, mainly by reducing exacerbations and the use of maintenance corticosteroids, but also by improving lung function and patient quality of life.

AREAS COVERED

Randomized controlled trials have convincingly demonstrated the efficacy of different biologics in improving the above outcomes. However, no head-to-head studies exist to compare their efficacy and many patients with severe asthma are eligible for more than one biologic agent. In this review, we present the effect of various biologics in the various outcomes as shown in randomized controlled trials and discuss their similarities and differences.

EXPERT OPINION

Both the initial choice of a biologic as well as the option of switching to another give the clinician an interesting but also difficult decision when choosing a biologic therapy for patients with severe asthma. This decision is mainly based on the individual characteristics of the patient, especially rate of exacerbations and use of systemic corticosteroids, but is also influenced by the presence of comorbidities and lung function impairment. No safety concerns have been raised around the use of these biologics.

Severe asthma in children: An official statement from Saudi Pediatric Pulmonology Association

In Saudi Arabia, the prevalence of pediatric asthma ranges between 8% and 25%. However, there are no sufficient data regarding severe asthma in childhood in Saudi Arabia. Therefore, a task force has been formed by the Saudi Pediatric Pulmonology Association which is a subsidiary group of the Saudi Thoracic Society and consists of Saudi experts with well-respected academic and clinical backgrounds in the fields of pediatric asthma as well as other respiratory diseases to write a consensus on definitions, phenotypes, and pathophysiology, evaluation, and management. To achieve this, the subject was divided into various sections, each of which was assigned to at least 2 experts. Without a central literature review, the authors searched the literature using their own strategies. To reach an agreement, the entire panel reviewed and voted on proposed findings and recommendations.

Interpretation of Clinical Efficacy of Biologics in Chronic Rhinosinusitis With Nasal Polyps via Understanding the Local and Systemic Pathomechanisms

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease treated with medication or surgery. For recalcitrant type 2 CRSwNP, biological agents have been effectively used to improve nasal polyp score, nasal congestion score, daily symptoms related to CRSwNP, and time to systemic corticosteroid use or revision surgery. Although general guidelines for using biologics to treat CRSwNP were proposed by the European Position Paper on Rhinosinusitis and Nasal Polyps in 2020 and various studies have tested their efficacy, there is much more to learn about biologics—specific indication and choice of biologics based on the endotypes, for instance. Understanding the vascular distribution of monoclonal antibodies and the differences in the vascularity of the non-polyp mucosa and nasal polyp tissue will not only aid understanding of each biologic’s clinical effect but also provide insights to establishing a more personalized approach to treating recalcitrant CRSwNP with biologics.

Eosinophils as Drivers of Severe Eosinophilic Asthma: Endotypes or Plasticity?

Asthma is now recognized as a heterogeneous disease, encompassing different phenotypes driven by distinct pathophysiological mechanisms called endotypes. Common phenotypes of asthma, referred to as eosinophilic asthma, are characterized by the presence of eosinophilia. Eosinophils are usually considered invariant, terminally differentiated effector cells and have become a primary therapeutic target in severe eosinophilic asthma (SEA) and other eosinophil-associated diseases (EADs). Biological treatments that target eosinophils reveal an unexpectedly complex role of eosinophils in asthma, including in SEA, suggesting that "not all eosinophils are equal". In this review, we address our current understanding of the role of eosinophils in asthma with regard to asthma phenotypes and endotypes. We further address the possibility that different SEA phenotypes may involve differences in eosinophil biology. We discuss how these differences could arise through eosinophil "endotyping", viz. adaptations of eosinophil function imprinted during their development, or through tissue-induced plasticity, viz. local adaptations of eosinophil function through interaction with their lung tissue niches. In doing so, we also discuss opportunities, technical challenges, and open questions that, if addressed, might provide considerable benefits in guiding the choice of the most efficient precision therapies of SEA and, by extension, other EADs.

Ding Chuan Tang Attenuates Airway Inflammation and Eosinophil Infiltration in Ovalbumin-Sensitized Asthmatic Mice

Asthma is a T helper 2 (Th2) cell-associated chronic inflammatory diseases characterized with airway obstruction, increased mucus production, and eosinophil infiltration. Conventional medications for asthma treatment cannot fully control the symptoms, and potential side effects are also the concerns. Thus, complement or alternative medicine (CAM) became a new option for asthma management. Ding Chuan Tang (DCT) is a traditional Chinese herbal decoction applied mainly for patients with coughing, wheezing, chest tightness, and asthma. Previously, DCT has been proved to improve children airway hyperresponsiveness (AHR) in a randomized and double-blind clinical trial. However, the mechanisms of how DCT alleviates AHR remain unclear. Since asthmatic features such as eosinophil infiltration, IgE production, and mucus accumulation are relative with Th2 responses, we hypothesized that DCT may attenuate asthma symptoms through regulating Th2 cells. Ovalbumin (OVA) was used as a stimulant to sensitize BALB/c mice to establish an asthmatic model. AHR was detected one day before sacrifice. BALF and serum were collected for immune cell counting and antibody analysis. Splenocytes were cultured with OVA in order to determine Th2 cytokine production. Lung tissues were collected for histological and gene expression analyses. Our data reveal that DCT can attenuate AHR and eosinophil accumulation in the 30-day sensitization asthmatic model. Histological results demonstrated that DCT can reduce cell infiltration and mucus production in peribronchial and perivascular site. In OVA-stimulated splenocyte cultures, a significant reduction of IL-5 and IL-13 in DCT-treated mice suggests that DCT may alleviate Th2 responses. In conclusion, the current study demonstrates that DCT has the potential to suppress allergic responses through the reduction of mucus production, eosinophil infiltration, and Th2 activity in asthma.

Fasting impairs type 2 helper T cell infiltration in the lung of an eosinophilic asthma mouse model

Eosinophilic asthma is a form of bronchial asthma that is caused by the pulmonary infiltration of eosinophils and accounts for approximately half of the patients with severe asthma. Several cell types of the immune system in synergy with the epithelial cells of the lung provoke an inflammatory response in patients with asthma. Recently, the effect of fasting on immune cells and inflammation has attracted considerable attention. Therefore, we examined whether fasting may serve as novel preventive strategy in patients with asthma. In our study, we employed a previously established mouse model of eosinophilic asthma. C57BL/6 mice were inoculated intranasally with interleukin‐33 and ovalbumin (OVA) in order to induce eosinophil infiltration in the lung and subjected to a 48‐h long fasting period directly after or 7 days postinoculation. We used flow cytometry to characterise infiltrated immune cells in the lung and measured the quantity of inflammatory cytokines as well as antigen‐specific immunoglobins (Ig) by ELISA. Our results indicated that fasting lowered the number of eosinophilic pulmonary infiltrates in the eosinophilic asthma model mice. Furthermore, fasting suppressed anti‐OVA IgG1 production. Fasting suppressed Th2 cytokine production by impairing Th2 accumulation in the lung. The findings suggest that fasting may be a novel preventive strategy for eosinophilic asthma.

Effect of omalizumab as add-on therapy to Quality of Life Questionnaire for Korean Asthmatics (KAQLQ) in Korean patients with severe persistent allergic asthma

BACKGROUND/AIMS

Omalizumab is the first biologic known to be effective in patients with severe allergic asthma.

METHODS

This study was conducted as a multicenter, single-group, open trial to evaluate the improvement in the quality of life with the additional administration of omalizumab for 24 weeks in Korean patients with severe persistent allergic asthma.

RESULTS

Of the 44 patients, 31.8% were men and the mean age was 49.8 ± 11.8 years. A score improvement of 0.5 points or more in the Quality of Life Questionnaire for Korean Asthmatics (KAQLQ) was noted in 50.0% (22/44) of the patinets. In the improved group, the baseline total immunoglobulin E (IgE) level and the amount of omalizumab used were higher, and the day and night asthma symptoms were more severe, compared to those in the non-improved group. According to the Global Evaluation of Treatment Effectiveness, favorable outcomes were found in 78.6% of patients. The Korean asthma control test (p < 0.005) and forced expiratory volume in 1 second % predicted (FEV1%; p < 0.01) improved significantly in patients who received omalizumab treatment, compared to that at week 0, and the total dose of rescue systemic corticosteroids significantly decreased (p < 0.05). The improved group on KAQLQ showed a significant improvement in FEV1% (p < 0.001).

CONCLUSION

Omalizumab can be considered a biological treatment for Korean patients with severe allergic asthma. It is recommended to consider omalizumab as add-on therapy in patients with high baseline total IgE levels and severe asthma symptoms.

Asthma Phenotypes as a Guide for Current and Future Biologic Therapies

Asthma has been increasingly recognized as being a heterogeneous disease with multiple distinct mechanisms and pathophysiologies. Evidence continues to build regarding the existence of different cell types, environmental exposures, pathogens, and other factors that produce a similar set of symptoms known collectively as asthma. This has led to a movement from a "one size fits all" symptom-based methodology to a more patient-centered, individualized approach to asthma treatment targeting the underlying disease process. A significant contributor to this shift to more personalized asthma therapy has been the increasing availability of numerous biologic therapies in recent years, providing the opportunity for more targeted treatments. When targeted biologics began to be developed for treatment of asthma, the hope was that distinct biomarkers would become available, allowing the clinician to determine which biologic therapy was best suited for which patients. Presence of certain biomarkers, like eosinophilia or antigen-specific IgE, is important features of specific asthma phenotypes. Currently available biomarkers can help with decision making about biologics, but are generally too broad and non-specific to clearly identify an asthma phenotype or the single biologic best suited to an asthmatic. Identification of further biomarkers is the subject of intense research. Yet, identifying a patient's asthma phenotype can help in predicting disease course, response to treatment, and biologic therapies to consider. In this review, major asthma phenotypes are reviewed, and the evidence for the utility of various biologics, both those currently on the market and those in the development process, in each of these phenotypes is explored.

Novel therapeutic approaches targeting endotypes of severe airway disease

Introduction: Severe asthma and chronic rhinosinusitis (CRS), with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP), are heterogeneous diseases characterized by different mechanistic pathways (endotypes) and variable clinical presentations (phenotypes).Areas covered: This review provides the clinician with an overview of the prevalence and clinical impact of severe chronic upper and lower airways disease and suggests a novel therapeutic approach with biological agents with possible biomarkers. To select relevant literature for inclusion in this review, we conducted a literature search using the PubMed database, using terms 'severe airways disease' AND 'endotype' AND 'treatment.' The literature review was performed for publication years 2010-2020, restricting the articles to humans and English language publications.Expert opinion: The coronavirus disease (COVID-19) pandemic has brought forth many challenges for patients with severe airway disease and healthcare practitioners involved in care. These patients could have an increased risk of developing severe SARS-CoV-2 disease, although treatment with biologics is not associated with a worse prognosis. Eosinopenia on hospital admission plays a key role as a diagnostic and prognostic biomarker.

Evolution of our view on the IgE molecule role in bronchial asthma and the clinical effect of its modulation by omalizumab: Where do we stand today?

Bronchial asthma is a heterogeneous disease whose definition and treatment are based on evidence of variable airway obstruction and airway inflammation. Despite the enormous increase in the amount of information on the pathogenesis of this disease, diagnosis is still an unresolved problem, as we still lack sensitive and specific biomarkers. On the other hand, at the turn of the 20th and 21st century, there was a rapid development of therapeutic modalities based on the principle of biological therapy. The first authorized drug matching these characteristics was omalizumab – a monoclonal antibody directed against immunoglobulin E (IgE). It has been used for the treatment of severe forms of bronchial asthma for more than 15 years, which is a sufficient time to acquire ways of its effective use and to assess whether the treatment with omalizumab has met our expectations. However, we continue to discover new and surprising facts about the effects of omalizumab treatment which leads to widening of therapeutic indications. In this work, a basic overview of the very complex role of the IgE molecule in the organism (with a special emphasis on allergic asthma) is discussed, and the most important practical and clinical consequences resulting from its modulation by targeted therapy with omalizumab are summarized.

Defining type 2 asthma and patients eligible for dupilumab in Italy: a biomarker-based analysis

Background

Asthma is a chronic disease characterized by airway hyperresponsiveness, inflammation and mucus production. In Type 2 asthma, two phenotypic components are often co-expressed (eosinophilic and allergic). Elevated biomarker levels, such as eosinophils (EOS), fraction of exhaled nitric oxide (FeNO) and immunoglobulin E (IgE), are key clinical indicators of Type 2 inflammation. Dupilumab has been recently approved for the treatment of uncontrolled severe Type 2 asthma. Type 2 asthma includes allergic and/or eosinophilic phenotypes. The aim of this analysis was to estimate the dupilumab-eligible population in Italy and characterize it by expected biomarker status.

Methods

A 4-step approach was carried out to calculate dupilumab-eligible population. The approach consisted in: (1) estimating the total number of asthma patients in Italy (using 2016–2017 Italian-adapted Global Initiative for Asthma -GINA- guidelines); (2) estimating the number of severe asthma patients with poorly controlled or uncontrolled disease (using the findings of two recent administrative claim analyses conducted in Italy); (3) stratifying the severe uncontrolled population by biomarker levels (EOS, FeNO and IgE) according to the outcomes of the QUEST trial (a clinical study assessing the efficacy of dupilumab in patients with uncontrolled moderate-to-severe asthma; NCT02414854); (4) identifying the sub-populations of severe uncontrolled asthma patients characterised by raised blood EOS and/or FeNO level (thus indicated to receive dupilumab).

Results

According to these estimates, about 3.3 million asthmatic patients live in Italy (6.10% of the population). Of them, almost 20 thousand (N = 19,960) have uncontrolled severe asthma. Dupilumab-eligible patients would be N = 15,988, corresponding to 80.1% of the total uncontrolled severe population. Most of these patients (89.3%; N = 14,271) have at least an increase of EOS level, while slightly more than half (51.9%; N = 8,303) have raised levels of both biomarkers. Increased FeNO levels without increased EOS are observed less frequently (N = 1,717; 10.7% of the eligible population).

Conclusions

There is a strong rationale for testing all asthma biomarkers during diagnosis and disease follow-up. Given the large availability and the limited costs, these tests are cost-effective tools to detect severe Type 2 asthma, stratify patients by phenotype, and drive appropriate treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12948-021-00146-9.

Genetic effects of allergen-specific IgE levels on exhaled nitric oxide in schoolchildren with asthma: The STOPPA twin study

BACKGROUND

Exhaled nitric oxide and blood eosinophils are clinical asthma T-helper type 2 markers in use. Immunoglobulin E (IgE) is often involved in the inflammation associated with atopic asthma. The effect of both blood eosinophils and allergen-specific IgE on exhaled nitric oxide levels is not completely understood. Twin-design studies can improve understanding of the underlying contribution of genetically and/or environmentally driven inflammation markers in asthma. Our aim was to disentangle the covariance between asthma and exhaled nitric oxide into genetic and environmental contributions that can account for inflammation markers in a paediatric population.

METHODS

This population-based, cross-sectional twin study enrolled 612 monozygotic (MZ) and same-sex dizygotic (DZ) schoolchildren. Multivariate structural equation modelling was utilized to separate the covariance between asthma and exhaled nitric oxide into genetic and/or environmental effects, taking allergen-specific IgE level and blood eosinophil count into account while controlling for confounding factors.

RESULTS

The cross-twin/cross-trait correlations had a higher magnitude in the MZ twins than in the DZ twins, indicating that genes affect the association. The likelihood ratio test for model fitting resulted in the AE model (ie additive genetic effects, A, and non-shared environmental effects, E) as the most parsimonious. A majority, 73%, of the phenotypic correlation between asthma and exhaled nitric oxide, r = .19 (0.05-0.33), was attributable to genetic effects which mainly was due to the allergen-specific IgE level.

CONCLUSIONS

This study indicates that the association between asthma and exhaled nitric oxide in children is to a large extent explained by genetics via allergen-specific IgE level and not blood eosinophils. This might partly explain the clinical heterogeneity in this group. A next step could be to include allergen-specific IgE level in multivariate omic studies.

SKP2-Promoted Ubiquitination of FOXO3 Promotes the Development of Asthma

Asthma is a respiratory disease with a dramatically increasing incidence globally. The present study explored the roles of S-phase kinase-associated protein 2 (SKP2) and forkhead box O3 (FOXO3) in asthma and their involvement in the Krüppel-like factor 15-lipoprotein receptor-related protein 5 (KLF15-LRP5) axis. SKP2 expression in patients with asthma and OVA-induced asthmatic Sprague Dawley rats was detected by reverse transcription quantitative PCR and Western blot assays. Alterations in SKP2 and LRP5 expression were evaluated in OVA-induced asthmatic rats, followed by measurement of inflammatory cytokines using ELISA and airway resistance using a methacholine challenge test. We applied TGF-β1 to establish the airway smooth muscle cell (ASMC) proliferation model of asthma. The FOXO3 ubiquitination and changes in cell biological behaviors were detected using immunoprecipitation, MTT, and Annexin V/propidium iodide assays. Flow cytometry was adopted to detect cell cycle, and ELISA was used to measure the concentrations of IL-4, IL-5, IL-13, and IgE in rat bronchoalveolar lavage fluid. SKP2 was highly expressed and FOXO3 was poorly expressed in patients with asthma and in OVA-induced asthmatic rats. SKP2 silencing decreased IL-4, IL-5, IL-13, and IgE expression in rat bronchoalveolar lavage fluid, whereas SKP2 enhanced FOXO3 ubiquitination to upregulate KLF15, which bound to the LRP5 promoter in TGF-β1-induced ASMCs and increased LRP5 expression. SKP2 enhanced airway hyperresponsiveness and inflammation in the OVA-induced rat model and augmented TGF-β1-induced ASMC proliferation by inhibiting the FOXO3/KLF15/LRP5 axis. Additionally, overexpressed SKP2 resulted in reduced numbers of ASMCs in the G1 phase but increased numbers in the G2/M phase. Collectively, we show that SKP2 promotes FOXO3 ubiquitination to suppress the KLF15-LRP5 axis, thereby exacerbating asthma.

The novel TRPA1 antagonist BI01305834 inhibits ovalbumin-induced bronchoconstriction in guinea pigs

Background

Asthma is a chronic respiratory disease in which the nervous system plays a central role. Sensory nerve activation, amongst others via Transient Receptor Potential Ankyrin 1 (TRPA1) channels, contributes to asthma characteristics including cough, bronchoconstriction, mucus secretion, airway hyperresponsiveness (AHR) and inflammation. In the current study, we evaluated the efficacy of the novel TRPA1 antagonist BI01305834 against AHR and inflammation in guinea-pig models of asthma.

Methods

First, a pilot study was performed in a guinea-pig model of allergic asthma to find the optimal dose of BI01305834. Next, the effect of BI01305834 on (1) AHR to inhaled histamine after the early and late asthmatic reaction (EAR and LAR), (2) magnitude of EAR and LAR and (3) airway inflammation was assessed. Precision-cut lung slices and trachea strips were used to investigate the bronchoprotective and bronchodilating-effect of BI01305834. Statistical evaluation of differences of in vivo data was performed using a Mann–Whitney U test or One-way nonparametric Kruskal–Wallis ANOVA, for ex vivo data One- or Two-way ANOVA was used, all with Dunnett’s post-hoc test where appropriate.

Results

A dose of 1 mg/kg BI01305834 was selected based on AHR and exposure data in blood samples from the pilot study. In the subsequent study, 1 mg/kg BI01305834 inhibited AHR after the EAR, and the development of EAR and LAR elicited by ovalbumin in ovalbumin-sensitized guinea pigs. BI01305834 did not inhibit allergen-induced total and differential cells in the lavage fluid and interleukin-13 gene expression in lung homogenates. Furthermore, BI01305834 was able to inhibit allergen and histamine-induced airway narrowing in guinea-pig lung slices, without affecting histamine release, and reverse allergen-induced bronchoconstriction in guinea-pig trachea strips.

Conclusions

TRPA1 inhibition protects against AHR and the EAR and LAR in vivo and allergen and histamine-induced airway narrowing ex vivo, and reverses allergen-induced bronchoconstriction independently of inflammation. This effect was partially dependent upon histamine, suggesting a neuronal and possible non-neuronal role for TRPA1 in allergen-induced bronchoconstriction.

Overlap of allergic, eosinophilic and type 2 inflammatory subtypes in moderate-to-severe asthma

Background

Current biologic therapies target allergic, eosinophilic or type 2 inflammation phenotypic asthma. However, frequency and degree of overlap among these subtypes is unclear.

Objective

To characterize overlap among allergic, eosinophilic and type 2 asthma phenotypes.

Methods

Post hoc analyses of baseline data were performed in two adult populations: (a) not selected for any asthma subtype (N = 935) and (b) selected for allergic asthma (N = 1049). Degree of overlap was examined using commonly accepted phenotypic definitions to guide treatment for allergic asthma (skin prick–positive and/or positive serum–specific immunoglobulin E > 0.35 kU/L) and eosinophilic asthma (blood eosinophil high count ≥ 300 cells/µL; low cut‐off ≥ 150 cells/µL). Consistent with previous studies, fractional exhaled nitric oxide high level of ≥ 35 ppb and low cut‐off of ≥ 25 ppb were selected as local markers of type 2 inflammation and to prevent overlap with the systemic eosinophilic asthma definition.

Results

In the non‐subtype–selected population, 78.0% had allergic asthma; of these, 39.5% had eosinophilic asthma and 29.5% had type 2 asthma. Within patients with eosinophilic asthma (40.6% of total), 75.8% had allergic asthma and 41.3% had type 2 asthma. Within patients with type 2 asthma (28.3% of total), 81.1% had allergic asthma and 59.2% had eosinophilic asthma. In the allergic asthma–selected population, 38.3% had eosinophilic asthma and 29.2% had type 2 asthma. Within patients with eosinophilic asthma, 46.3% had type 2 asthma. Within patients with type 2 asthma, 60.8% had eosinophilic asthma. Overlaps among subtypes increased at low cut‐off values.

Conclusions and clinical relevance

In this post hoc analysis in adults with moderate‐to‐severe asthma, allergic asthma was the most prevalent phenotype, followed by eosinophilic and type 2 asthma. Despite observed overlaps, a considerable proportion of patients had only a predominantly allergic subtype. Understanding the degree of overlap across phenotypes will help patient management and guide treatment options.

Biologics for atopic diseases: Indication, side effect management, and new developments

With the advent of biologicals, more and more therapeutics are available that specifically address specific switch points in the pathomechanism of immunologically dominated diseases. Thus, the focus of diagnostics and therapy (precision medicine) is more on the individual disease characteristics of the individual patient. Regarding the different phenotypes of atopic diseases, severe asthma was the first entity for which biologicals were approved, followed by urticaria, and finally atopic dermatitis and chronic rhinosinusitis with nasal polyps. Experience in the treatment of severe bronchial asthma has shown that the intensity of the response to biological therapy depends on the quality of clinical and immunological phenotyping of the patients. This also applies to different diseases of the atopic form, as patients can suffer from several atopic diseases at the same time, each with different characteristics. Biologics are already emerging that may represent a suitable therapy for allergic bronchial asthma, which often occurs together with severe neurodermatitis, and chronic rhinosinusitis with nasal polyps. In practice, however, the question of possible combinations of biologicals for the therapy of complex clinical pictures of individual patients is increasingly arising. In doing so, the side effect profile must be taken into account, including hypersensitivity reactions, whose diagnostic and logistical management must aim at a safe and efficient therapy of the underlying disease. Increased attention must also be paid to biological therapy in pregnancy and planned (predictable) vaccinations as well as existing infections, such as SARS-CoV-2 infection. Before starting a biological therapy, the immune status should be checked with regard to chronic viral and bacterial infections and, if necessary, the vaccination status should be refreshed or missing vaccinations should be made up for before starting therapy. Currently, reliable data on the effect of biologicals on the immunological situation of SARS-CoV-2 infection and COVID-19 are not available. Therefore, research and development of suitable diagnostic methods for detection of immunologically caused side effects as well as detection of potential therapy responders and non-responders is of great importance.

Applying personalized medicine to adult severe asthma

Background: Severe asthma is a heterogeneous disease that consists of various phenotypes driven by different pathways. Associated with significant morbidity, an important negative impact on the quality of life of patients, and increased health care costs, severe asthma represents a challenge for the clinician. With the introduction of various antibodies that target type 2 inflammation (T2) pathways, severe asthma therapy is gradually moving to a personalized medicine approach. Objective: The purpose of this review was to emphasize the important role of personalized medicine in adult severe asthma management. Methods: An extensive research was conducted in medical literature data bases by applying terms such as "severe asthma" associated with "structured approach," "comorbidities," "biomarkers," "phenotypes/endotypes," and "biologic therapies." Results: The management of severe asthma starts with a structured approach to confirm the diagnosis, assess the adherence to medications and identify confounding factors and comorbidities. The definition of phenotypes or endotypes (phenotypes defined by mechanisms and identified through biomarkers) is an important step toward the use of personalized medicine in asthma. Severe allergic and nonallergic eosinophilic asthma are two defined T2 phenotypes for which there are efficacious targeted biologic therapies currently available. Non-T2 phenotype remains to be characterized, and less efficient target therapy exists. Conclusion: Despite important progress in applying personalized medicine to severe asthma, especially in T2 inflammatory phenotypes, future research is needed to find valid biomarkers predictive for the response to available biologic therapies to develop more effective therapies in non-T2 phenotype.

Plasma Brain-Derived Neurotrophic Factor (BDNF) Concentration and BDNF/TrkB Gene Polymorphisms in Croatian Adults with Asthma

Brain-derived neurotrophic factor (BDNF) and its tropomyosin-related kinase B (TrkB) receptor might contribute to normal lung functioning and immune responses; however, their role in asthma remains unclear. Plasma BDNF concentrations, as well as BDNF and NTRK2 (TrkB gene) polymorphisms, were investigated in 120 asthma patients and 120 healthy individuals using enzyme-linked immunosorbent assay and polymerase chain reaction, respectively. The genotype and allele frequencies of BDNF Val66Met (rs6265) and NTRK2 rs1439050 polymorphisms did not differ between healthy individuals and asthma patients, nor between patients grouped according to severity or different asthma phenotypes. Although plasma BDNF concentrations were higher among healthy subjects carrying the BDNF Val66Met GG genotype compared to the A allele carriers, such differences were not detected in asthma patients, suggesting the influences of other factors. Plasma BDNF concentration was not affected by NTRK2 rs1439050 polymorphism. Asthma patients had higher plasma BDNF concentrations than control subjects; however, no differences were found between patients subdivided according to asthma severity, or Type-2, allergic, and eosinophilic asthma. Higher plasma BDNF levels were observed in asthma patients with aspirin sensitivity and aspirin-exacerbated respiratory disease. These results suggest that plasma BDNF may serve as a potential peripheral biomarker for asthma, particularly asthma with aspirin sensitivity.

Assessing the nature of asthma in African epidemiological studies: a scoping review protocol

BACKGROUND

Asthma is one of the most common chronic respiratory conditions in the world and is increasing in prevalence, particularly in Africa and other low-income countries. The disproportionately high numbers of premature deaths and severe or uncontrolled cases in many African countries are indicative of their inability to cope with a costly disease like asthma. Progress has, however, been made in understanding the complex and heterogeneous nature of the disease. The objective of this study will be to summarise the epidemiological literature on the nature of asthma in African countries.

METHODS

We registered a study protocol for a scoping review. The review was designed following the Arksey and O'Malley framework. We will search PubMed/MEDLINE, African Journals Online (AJOL) and relevant grey literature (e.g. Google Scholar, EBSCOhost) from January 1990 onwards. Only primary epidemiological studies of asthma (e.g. frequency, disease mechanisms, associated risk factors and comorbidities) written in English and conducted in Africa will be included. Two reviewers will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion. Findings will be reported using narrative synthesis and tabulation of the summaries.

DISCUSSION

This scoping review will capture the state of the current epidemiological literature on asthma in African countries. Results will be published in a peer-reviewed journal. We anticipate this review will identify gaps and make recommendations for future areas of study.

SCOPING REVIEW REGISTRATION

Open Science Framework http://osf.io/n2p87/.

Surgery in Nasal Polyp Patients: Outcome After a Minimum Observation of 10 Years

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) often requires surgery, but recurrence even after surgery is common. Recurrence rates largely vary in literature and asthma seems to be a comorbid factor.

OBJECTIVE

In this study, we aim to estimate disease recurrence during a long-term follow-up, together with the investigation of possible predicting and/or influencing parameters.

METHODS

Out of 196 patients operated for CRSwNP between 01/2000 and 01/2006, 133 patients had a follow-up of at least 10 years and could be included. The inflammatory profile at surgery was determined on nasal tissue and sinonasal secretions, and included analysis of eosinophils, eosinophilic-rich mucus (ERM) typically containing Charcot-Leyden crystals (CLC), and fungal hyphae (FH). During follow-up, recurrence, received treatments and comorbidities were collected.

RESULTS

Out of the 133 included patients, local eosinophilia was present in 81% and ERM in 60%. Recurrence during follow-up was observed in 62%, and was associated with local eosinophilia and ERM (both p < 0.001). Asthma was present in 28% at inclusion, and 17% developed asthma after surgery during follow-up. The presence of asthma, at inclusion as well as developed during follow-up, was significantly associated with recurrence of CRSwNP (p = 0.001 for group comparison).

CONCLUSION

Recurrence after CRSwNP surgery is common when a long-term follow-up is taken into account. ERM detected in sinonasal secretions at surgery seems to be a predictive factor for recurrence and need for revision surgery. Asthma is a frequently found comorbid factor in CRSwNP, develops even at higher age despite surgical treatment for CRSwNP, and is also associated with a higher recurrence rate. Sustained medical care after surgery is mandatory.

Primary prevention of asthma: from risk and protective factors to targeted strategies for prevention

Asthma is a complex disease that often starts in childhood. Genomic and environmental factors as well as aberrant immune maturation early in life can contribute to the onset of disease, with great disparity over time and geographical regions. Epidemiological studies have scrutinised environmental exposures and attempted to translate these exposures into prevention strategies. Some approaches for patients with asthma have been successful (eg, smoking ban, the Finnish Asthma Programme), and primary prevention of wheeze in pre-school children (age 0-5 years) by the supplementation of vitamin D or fish oil, or both, to pregnant women seems promising. Several recent prevention initiatives are based on strong asthma-protective environmental microbial exposures associated with traditional rural lifestyles. Preclinical studies with various bacterial lysates, bacterial and dietary metabolites, or helminthic compounds have yielded promising results that await translation into clinical practice. Given the immense societal and individual burden of asthma, there is an urgent need to further develop novel strategies to eradicate the disease.

Biological treatments for severe asthma

Severe asthma patients comprise about 3% to 13% of all asthma patients, but they have higher hospital utilization rates and higher medical costs than those of nonsevere asthma patients. Treatment methods for severe asthma patients are still lacking; however, the recent development of biologics is expected to have a positive effect. The biological therapies developed so far are mainly aimed at treating asthma patients with type 2 inflammation. These biologics have been found to reduce symptoms of asthma, improve lung function, reduce the use of oral corticosteroids, and improve quality of life of patients. This article reviews the mechanism of action and indications for approved biologics and discusses what should be considered when choosing biologics.

How do biologicals and other novel therapies effect clinically used biomarkers in severe asthma?

While there has been much interest in using biomarkers to select patients for particular targeted therapies, there has been much less attention paid to how these biomarkers change in patients once treatment begins. This is an area of great interest to practising clinicians, especially respiratory physicians and allergists who manage severe asthma. In this article, we review monoclonal antibodies and related targeted therapies, especially those that are currently available or in late stage clinical trials, focussing on the differential effects such agents have on biomarkers in widespread clinical practice such as eosinophils, FeNO and total IgE. Serial measurements of biomarkers can be useful in determining whether a particular targeted therapy is having its expected biological effect and invaluable in assessing the reasons for treatment failure should that occur.

Allergen immunotherapy for respiratory allergy: to what extent can the risk of systemic reactions be reduced?

INTRODUCTION

Allergen immunotherapy is an effective treatment for respiratory allergy, but the administration to patients of extracts of the causative allergen may elicit systemic reactions, which include, particularly with subcutaneous immunotherapy (SCIT), anaphylaxis. In the past, the occurrence (tough rare) of fatal reactions has represented a serious problem that has limited the prescription of SCIT.

AREAS COVERED

The authors analyzed in this review the safety data of SCIT, especially concerning the years following the identification of uncontrolled asthma at the moment of allergen injection as the major risk of life-threatening reactions and fatalities. The safety of SLIT, which is far better than SCIT, was analyzed and its specific risk factors for systemic reactions were highlighted.

EXPERT OPINION

Presently, the safety profile of SCIT and SLIT is satisfactory, provided the treatment is administered by physicians experienced in this treatment, who are aware of the known risk factors for severe reactions and who implement all measures to avoid them. For SLIT, which is self-administered by the patient, receiving the first dose under medical control is recommended.

Bringing asthma care into the twenty-first century

Despite access to diagnostic tests and effective therapies, asthma often remains misdiagnosed and/or poorly controlled or uncontrolled. In this review, we address the key issues of asthma diagnosis and management, recent evidence for levels of asthma control, the consequences of poor control and, in line with that, explore the potential reasons for poor asthma control and acute exacerbations. Based on recent evidence and current guidelines, we also aim to provide practical answers to the key questions of how to improve asthma management, with the best possible prevention of exacerbations, addressing the basics—adherence, inhaler misuse, obesity and smoking—and how to facilitate a new era of asthma care in the twenty-first century. We hope this review will be useful to busy primary care clinicians in their future interactions with their patients with both suspected and proven asthma.

IL‑27 suppresses airway inflammation, hyperresponsiveness and remodeling via the STAT1 and STAT3 pathways in mice with allergic asthma

Type 2 cytokine-associated immunity may be involved in the pathogenesis of allergic asthma. Although interleukin 27 (IL-27) has been reported as an initiator and suppressor of T-helper 1 (Th1) and T-helper 2 (Th2) responses, respectively, its effects on the development of asthma remain unclear. In the present study, mice were induced and challenged with ovalbumin and received subsequent intranasal administration of IL-27. Total and differential cell counts were determined from Wright-Giemsa-stained cytospins, whereas the cytokine levels were detected using ELISA. In addition, the expression levels of signal transducer and activator of transcription (STAT) 1, STAT3, GATA-binding protein-3 (GATA3) and T-bet (T-box transcription factor) were analyzed in T cells by western blot analysis. Their corresponding mRNA expression levels were determined by quantitative PCR. Airway remodeling was assessed by conventional pathological techniques. The results indicated that intranasal administration of IL-27 ameliorated airway inflammation and hyperresponsiveness in an acute model of asthma. Furthermore, IL-27 prevented airway remodeling in a chronic model of asthma. Following administration of IL-27, the mRNA expression levels of STAT1 and T-bet were upregulated, while those of GATA3 were downregulated. Moreover, the phosphorylation levels of STAT1 and STAT3 were increased. Taken together, these findings demonstrated that intranasal administration of IL-27 ameliorated Th2-related allergic lung inflammation and remodeling in mouse models of asthma by repairing both the STAT1 and STAT3 pathways.

Bronchial Asthma: Current Trends in Treatment

Asthma is a heterogenous disease which pathophysiology is still poorly understood. Asthma was traditionally divided into allergic (extrinsic) and non-allergic (intrinsic) types, while patients with allergic type responded better to corticosteroids. Since 2013 the definition of asthma has changed. Recently, better insight into clinical consi -derations and underlying inflammatory phenotypes has been gained. Defining these phenotypes has already led to more specific clinical trials and, therefore, to more personalized and successfully targeted therapy. For future, much more effort is put in identifying new phenotype-specific biomarkers which could be helpful in stratification of heterogeneous patients with asthma.

Severe asthma and eligibility for biologics in a Brazilian cohort

OBJECTIVE

This study aims to describe the eligibility for biologic therapies for severe asthma (SA) in a cohort of patients attending the Program for Control of Asthma (ProAR) in Bahia, Brazil.

METHODS

Data from SA patients (≥18 years old) attending the ProAR, that were included in a case-control study conducted from 2013 to 2015, were used to reassess patients according to a modified ERS/ATS 2014 SA criteria. Patients were then classified according to the eligibility for SA biological therapy based on current prescription labels.

RESULTS

From 544 patients in the cohort, 531 (97.6%) were included and 172 (32.4%) were identified as SA patients according to the ERS/ATS 2014 modified criteria. Of these 172 patients, 69 (40.1%) were ineligible for any of the biologicals approved for asthma (omalizumab, mepolizumab, reslizumab and benralizumab), 60 (34.9%) patients were eligible for one of the biological therapies, and 10 (5.8%) patients were eligible for all biological therapies.

CONCLUSIONS

More than half of patients with SA were eligible for biologic therapy in our study, but none of them received this form of treatment. Almost half of them were not eligible to any of the approved biologics, however. The variability and overlap in patients' eligibility highlight the importance of evaluating each patient individually for a more personalized treatment approach. While there is a need to increase access for some of those eligible that may really need a biologic treatment, continuous efforts are required to develop alternatives to those who are not eligible.

Serum periostin levels in asthma patients in relation to omalizumab therapy and presence of chronic rhinosinusitis with nasal polyps

INTRODUCTION

The serum periostin level is a promising biomarker of type 2- high inflammation pattern of bronchial asthma. It has been proven that serum periostin levels decrease in response to systemic and inhaled corticosteroid (ICS) therapy. However, we have only limited knowledge about changes in serum periostin levels reflecting omalizumab (OMA) treatment and other variables, such as chronic rhinosinusitis with nasal polyps (CRSwNP).

AIM

To critically appraise clinically relevant parameters influencing periostin levels in asthma patients.

MATERIAL AND METHODS

A pilot, cross-sectional, observational study to assess serum periostin levels of 48 asthma patients (38 treated by conventional therapy comprising ICS and 10 treated by ICS and OMA as an add-on therapy) with respect to asthma clinical traits, comorbidities and to other biomarkers of type 2-high asthma phenotype (total IgE, absolute and relative eosinophil count, eosinophilic cationic protein (ECP) and a fraction of exhaled NO (FeNO)).

RESULTS

Serum periostin correlates with total IgE levels (Spearman rho = 0.364, p = 0.025) in a subgroup of conventionally treated patients, and with eosinophil count (Spearman rho = 0.401, p = 0.021) in a subgroup of patients with concurrent CRSwNP. Serum periostin levels were decreased in omalizumab-treated patients in comparison to conventionally treated patients (p = 0.025). This effect was remarkably apparent only if CRSwNP was not present (p = 0.005). Conversely, we measured elevated periostin levels in OMA-treated patients with concurrent CRSwNP (p = 0.017).

CONCLUSIONS

Serum periostin production is significantly associated with treatment modality (omalizumab vs. conventional) and presence of CRSwNP. These variables need to be taken into account to interpret periostin levels accurately.

Omics for the future in asthma

Asthma is a common, complex, multifaceted disease. It comprises multiple phenotypes, which might benefit from treatment with different types of innovative targeted therapies. Refining these phenotypes and understanding their underlying biological structure would help to apply precision medicine approaches. Using different omics methods, such as (epi)genomics, transcriptomics, proteomics, metabolomics, microbiomics, and exposomics, allowed to view and investigate asthma from diverse angles. Technological advancement led to a large increase in the application of omics studies in the asthma field. Although the use of omics technologies has reduced the gap between bench to bedside, several design and methodological challenges still need to be tackled before omics can be applied in asthma patient care. Collaborating under a centralized harmonized work frame (such as in consortia, under consistent methodologies) could help worldwide research teams to tackle these challenges. In this review, we discuss the transition of single biomarker research to multi-omics studies. In addition, we deliberate challenges such as the lack of standardization of sampling and analytical methodologies and validation of findings, which comes in between omics and personalized patient care. The future of omics in asthma is encouraging but not completely clear with some unanswered questions, which have not been adequately addressed before. Therefore, we highlight these questions and emphasize on the importance of fulfilling them.

Role of Biologics in Asthma

Patients with severe uncontrolled asthma have disproportionally high morbidity and healthcare utilization as compared with their peers with well-controlled disease. Although treatment options for these patients were previously limited, with unacceptable side effects, the emergence of biologic therapies for the treatment of asthma has provided promising targeted therapy for these patients. Biologic therapies target specific inflammatory pathways involved in the pathogenesis of asthma, particularly in patients with an endotype driven by type 2 (T2) inflammation. In addition to anti-IgE therapy that has improved outcomes in allergic asthma for more than a decade, three anti-IL-5 biologics and one anti-IL-4R biologic have recently emerged as promising treatments for T2 asthma. These targeted therapies have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life in appropriately selected patients. In addition to the currently approved biologic agents, several biologics targeting upstream inflammatory mediators are in clinical trials, with possible approval on the horizon. This article reviews the mechanism of action, indications, expected benefits, and side effects of each of the currently approved biologics for severe uncontrolled asthma and discusses promising therapeutic targets for the future.

Prevalence, disease burden, and treatment reality of patients with severe, uncontrolled asthma in Japan

BACKGROUND

The severe asthma and severe, uncontrolled asthma (SUA) populations in Japan are not well-studied. We investigated the prevalence of continuously treated severe asthma and SUA patients, their disease burden, and the treatment reality via a Japanese health insurance claims database.

METHODS

Continuously treated asthma patients (patients prescribed inhaled corticosteroids for asthma ≥4 times in the past year) aged ≥17 years at the index date (latest visit between April 2014 and March 2015 for asthma treatment) were included in this analysis (KEIFU study, UMIN000027695). Asthma severity and control status at the index date were defined using modified criteria of ERS/ATS guidelines. Asthma hospitalization, oral corticosteroid (OCS) use, and total medical expenses were calculated using data up to 12 months post-index date.

RESULTS

We identified 10,579 patients as continuously treated asthma patients. Of these, 823 (7.8%) had severe asthma; 267 (2.5%) and 556 (5.3%) patients had SUA and severe, controlled asthma (SCA), respectively. Compared with SCA and mild to moderate asthma patients, a greater percentage of SUA patients required hospitalization (13.7%, 6.2%, and 3.0%, respectively) and were prescribed OCSs (67.4%, 45.9%, and 16.2%, respectively). Yearly total medical expenses were also greater for SUA patients (mean [standard deviation]: 8346 [12,280], vs 5989 [10,483] and 3422 [8800] USD, respectively).

CONCLUSIONS

The percentages of severe asthma and SUA patients continuously treated in Japan were obtained through this large-scale analysis using a health insurance claims database. SUA patients had greater medical and economic burdens, suggesting more appropriate treatment is required according to the treatment guidelines.

Single and Synergistic Effects of Type 2 Cytokines on Eosinophils and Asthma Hallmarks

The type 2 cytokines IL-5, IL-13, and IL-4 play an important role in the induction and progression of asthma. According to the Global Initiative for Asthma guidelines, blood eosinophil numbers are one marker that helps to guide treatment decisions in patients suffering from severe forms of asthma. Effects of type 2 cytokines were analyzed, alone or in combination, on eosinophils in blood and other compartments and on the development of asthma symptoms. C57BL/6 mice received a single intranasal application of equimolar amounts of IL-5, IL-13, and IL-4, alone or in combination. Numbers, activation state, and migratory behavior of eosinophils in bone marrow (BM), blood, lung, and bronchoalveolar lavage as well as airway hyperresponsiveness and goblet cell metaplasia were evaluated. Only IL-13 was associated with airway eosinophilia, development of airway hyperresponsiveness, and goblet cell metaplasia, without any synergistic effects. IL-5 increased the number of eosinophils in BM and lung tissue but failed to affect structural changes. IL-4 had similar, but weaker, effects to IL-13. Cytokine combinations synergistically affected eosinophils but failed to enhance IL-13-driven effects on lung function or goblet cell metaplasia. IL-5 and IL-13 markedly increased eosinophil numbers locally in lung and airways and distally in blood and BM, whereas IL-5 and IL-4 only increased eosinophils in lung and BM. IL-13 together with IL-4 failed to demonstrate any synergistic effect. These insights into single and combined effects of type 2 cytokines on disease-driving mechanisms could improve understanding of the impact and effectiveness of new therapies in asthma.

Mixed cell type in airway inflammation is the dominant phenotype in asthma patients with severe chronic rhinosinusitis

BACKGROUND

Asthma often coexists with chronic rhinosinusitis (CRS). Recent studies revealed that sinus inflammation in asthmatic patients was related to eosinophilic inflammation. However, the relationship between the severity of CRS and four different sputum inflammatory phenotypes as defined by the proportion of eosinophils and neutrophils is unknown. The aim of this study was to examine the impact of the severity of CRS on lower airway and systemic inflammation in asthmatic patients.

METHODS

We enrolled 57 adult asthmatic patients who underwent sinus computed tomography (CT). The severity of CRS was evaluated by the Lund-Mackay score (LMS). The induced sputum inflammatory phenotype was defined by eosinophils (≥/<2%) and neutrophils (≥/<60%). Peripheral blood mononuclear cells (PBMC) were collected to examine cytokine productions.

RESULTS

The median LMS of subjects was 6 (interquartile range, 0-11.5). The sputum inflammatory cell phenotype was categorized as paucicellular (n = 14), neutrophilic (n = 11), eosinophilic (n = 20), or mixed (n = 12). LMS was positively correlated with the percentage of blood eosinophils, sputum eosinophils, and mean fluorescence intensity (MFI) of IL-5 on CD4⁺ T cells. In the severe CRS group (LMS, 12-24), the number of mixed cellular phenotypes was higher than that in the group without CRS (LMS, 0-4) and mild-to-moderate CRS group (LMS, 5-11).

CONCLUSIONS

In asthmatic patients with severe CRS, the proportion of the mixed cellular inflammatory phenotype was increased as well as eosinophilic inflammation.

Body Mass Index and C-reactive Protein Are Potential Predictors of Asthma Development in Egyptian Polycystic Ovary Syndrome Patients

BACKGROUND

Recent studies suggest asthma prevalence in polycystic ovary syndrome (PCOS) patients. This is the first study to explore asthma prevalence among Egyptian PCOS patients. It highlighted common findings in PCOS and asthma. It investigated whether these findings could serve as potential predictors of asthma.

METHODS

A hundred PCOS patients, sixty asthmatic patients and thirty apparently healthy females of matched age were included. Body mass index (BMI), C-reactive protein (CRP), IL-6, IgE, 25 (OH) vitamin D, testosterone and lipid profile were measured.

RESULTS

Both PCOS and asthmatics had significantly higher BMI, Total cholesterol (TC), LDL-C, IgE, CRP and IL-6 (P<0.001) and lower 25 (OH) vitamin D levels (P<0.001) compared to controls. Within the PCOS group, 47 patients developed asthma with a significant increase in BMI (P=0.003), CRP and IgE levels (P<0.001) compared to non-asthmatic PCOS. Both asthmatic PCOS and asthmatics expressed elevated BMI, IgE, IL-6 and CRP levels, but with no significant difference between them. Asthmatic PCOS showed significantly higher testosterone and dyslipidemia profile. Multivariate regression revealed that BMI and CRP could predict asthma development within PCOS (OR=1.104, C.I 1.004-1.2 and OR=1, C.I. 1-1.02), respectively. Receiver operating characteristic (ROC) curve showed that BMI and CRP at a cutoff value 28.5 kg/m2 and 117.6 nmol/L respectively could differentiate between asthmatic and non-asthmatic PCOS with sensitivity 63.8 % and specificity 62% for BMI, and sensitivity and specificity of 66% for CRP.

CONCLUSIONS

This study shows that BMI and CRP are predictors of asthma development in Egyptian PCOS.

The RNA-binding protein Mex-3B plays critical roles in the development of steroid-resistant neutrophilic airway inflammation

While most asthma can be treated with steroids, about 10%, called severe asthma, is refractory to steroids. It has recently been shown that in a subgroup of severe asthma cases, neutrophils that infiltrate into the airways play an important role in inflammation. However, the mechanisms underlying this increased neutrophil infiltration are not well understood. Here, using a mouse model of steroid-resistant neutrophilic inflammation, we show that mice deficient for the RNA-binding protein Mex-3B have significantly less neutrophil infiltration in the airways than wild-type mice. We further demonstrate that Mex-3B post-transcriptionally upregulates CXCL2, a chemokine that induces neutrophil chemotaxis and migration. Moreover, we show that treatment with either anti-CXCL2 antibody or anti-Mex-3B antisense oligonucleotide suppresses neutrophilic allergic airway inflammation. These results suggest that Mex-3B-mediated induction of CXCL2 is crucial for steroid-resistant neutrophilic allergic airway inflammation. Our findings suggest new strategies for therapeutic intervention in steroid-resistant severe asthma.

Application of structured statistical analyses to identify a biomarker predictive of enhanced tralokinumab efficacy in phase III clinical trials for severe, uncontrolled asthma

Background

Tralokinumab is an anti–interleukin (IL)-13 monoclonal antibody investigated for the treatment of severe, uncontrolled asthma in two Phase III clinical trials, STRATOS 1 and 2. The STRATOS 1 biomarker analysis plan was developed to identify biomarker(s) indicative of IL-13 activation likely to predict tralokinumab efficacy and define a population in which there was an enhanced treatment effect; this defined population was then tested in STRATOS 2.

Methods

The biomarkers considered were blood eosinophil counts, fractional exhaled nitric oxide (FeNO), serum dipeptidyl peptidase-4, serum periostin and total serum immunoglobulin E. Tralokinumab efficacy was measured as the reduction in annualised asthma exacerbation rate (AAER) compared with placebo (primary endpoint measure of STRATOS 1 and 2). The biomarker analysis plan included negative binomial and generalised additive models, and the Subgroup Identification based on Differential Effect Search (SIDES) algorithm, supported by robustness and sensitivity checks. Effects on the key secondary endpoints of STRATOS 1 and 2, which included changes from baseline in standard measures of asthma outcomes, were also investigated. Prior to the STRATOS 1 read-out, numerous simulations of the methodology were performed with hypothetical data.

Results

FeNO and periostin were identified as the only biomarkers potentially predictive of treatment effect, with cut-offs chosen by the SIDES algorithm of > 32.3 ppb and > 27.4 ng/ml, respectively. The FeNO > 32.3 ppb subgroup was associated with greater AAER reductions and improvements in key secondary endpoints compared with the periostin > 27.4 ng/ml subgroup. Upon further evaluation of AAER reductions at different FeNO cut-offs, ≥37 ppb was chosen as the best cut-off for predicting tralokinumab efficacy.

Discussion

A rigorous statistical approach incorporating multiple methods was used to investigate the predictive properties of five potential biomarkers and to identify a participant subgroup that demonstrated an enhanced tralokinumab treatment effect. Using STRATOS 1 data, our analyses identified FeNO at a cut-off of ≥37 ppb as the best assessed biomarker for predicting enhanced treatment effect to be tested in STRATOS 2. Our findings were inconclusive, which reflects the complexity of subgroup identification in the severe asthma population.

Trial registration

STRATOS 1 and 2 are registered on ClinicalTrials.gov (NCT02161757 registered on June 12, 2014, and NCT02194699 registered on July 18, 2014).

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0889-4) contains supplementary material, which is available to authorized users.

The emergence of new biologics for severe asthma

Patients with severe asthma experience severe symptoms and frequent exacerbations despite intensive treatment with inhaled and oral glucocorticoids. Biologics for severe asthma aim to reduce asthma-related and glucocorticoid-induced morbidity. Recently, new biologics targeting interleukin (IL)-5, IL-5 receptor and IL-4/IL-13, which are all cytokines involved in so-called type 2 airway inflammation, were approved for severe asthma. They show a reduction in exacerbation rate and an oral glucocorticoid-sparing effect. Studies with upstream biologics targeting alarmin cytokines such as thymic stromal lymphopoietin (TSLP) and IL-33 are underway, and newly designed bispecific antibodies targeting more than one pathway are in early phases of development. Such pathway-targeted add-on treatments will soon become standard of care for all patients with severe asthma.

Engineering of anti-human interleukin-4 receptor alpha antibodies with potent antagonistic activity

Development of antagonistic antibody (Ab) against interleukin-4 receptor alpha (IL-4Rα) subunit of IL-4/IL-13 receptors is a promising therapeutic strategy for T helper 2 (TH2)-mediated allergic diseases such as asthma and atopic dermatitis. Here we isolated anti-human IL-4Rα antagonistic Abs from a large yeast surface-displayed human Ab library and further engineered their complementarity-determining regions to improve the affinity using yeast display technology, finally generating a candidate Ab, 4R34.1.19. When reformatted as human IgG1 form, 4R34.1.19 specifically bound to IL-4Rα with a high affinity (KD ≈ 178 pM) and effectively blocked IL-4- and IL-13-dependent signaling in a reporter cell system at a comparable level to that of the clinically approved anti-IL-4Rα dupilumab Ab analogue. Epitope mapping by alanine scanning mutagenesis revealed that 4R34.1.19 mainly bound to IL-4 binding sites on IL-4Rα with different epitopes from those of dupilumab analogue. Further, 4R34.1.19 efficiently inhibited IL-4-dependent proliferation of T cells among human peripheral blood mononuclear cells and suppressed the differentiation of naïve CD4+ T cells from healthy donors and asthmatic patients into TH2 cells, the activities of which were comparable to those of dupilumab analogue. Our work demonstrates that both affinity and epitope are critical factors for the efficacy of anti-IL-4Rα antagonistic Abs.

T cells in severe childhood asthma

Severe asthma in children is a debilitating condition that accounts for a disproportionately large health and economic burden of asthma. Reasons for the lack of a response to standard anti-inflammatory therapies remain enigmatic. Work in the last decade has shed new light on the heterogeneous nature of asthma, and the varied immunopathologies of severe disease, which are leading to new treatment approaches for the individual patient. However, most studies to date that explored the immune landscape of the inflamed lower airways have focused on adults. T cells are pivotal to the inception and persistence of inflammatory processes in the diseased lungs, despite a contemporary shift in focus to immune events at the epithelial barrier. This article outlines current knowledge on the types of T cells and related cell types that are implicated in severe asthma. The potential for environmental exposures and other inflammatory cues to condition the immune environment of the lung in early life to favour pathogenic T cells and steroid resistance is discussed. The contributions of T cells and their cytokines to inflammatory processes and treatment resistance are also considered, with an emphasis on new observations in children that argue against conventional type 1 and type 2 T cell paradigms. Finally, the ability for new technologies to revolutionize our understanding of T cells in severe childhood asthma, and to guide future treatment strategies that could mitigate this disease, is highlighted.