Asthma Endotyping and Biomarkers in Childhood Asthma

Type 2 Inflammation and Asthma in Children: A Narrative Review

Increased understanding of the underlying pathophysiology has highlighted the heterogeneity of asthma and identified that most children with asthma have type 2 inflammation with elevated biomarkers, such as blood eosinophils and/or fractional exhaled nitric oxide. Although in the past most of these children may have been categorized as having allergic asthma, identifying the type 2 inflammatory phenotype provides a mechanism to explain both allergic and non-allergic triggers in pediatric patients with asthma. Most children achieve control with low to medium doses of inhaled corticosteroids. However, in a small but significant proportion of children, asthma remains uncontrolled despite maximum conventional treatment, with an increased risk of severe exacerbations. In this review, we focus on the role of type 2 inflammation and allergic processes in children with asthma, together with evidence of the efficacy of available treatment options for those who experience severe symptoms.

Bifidobacterium animalis subsp. lactis CCFM1274 relieved allergic asthma symptoms by modifying intestinal tryptophan metabolism in mice

Approximately two-thirds of patients with asthma, a common inflammatory airway disease, are thought to present with allergies. Probiotics and tryptophan metabolites are becoming increasingly important in treating allergic asthma. This study aimed to identify potential probiotic strains and tryptophan metabolites that could alleviate asthma symptoms. Based on in vitro fermentation experiments, we evaluated variations in probiotic capacity to metabolize tryptophan. Of the eight tested strains, Bifidobacterium animalis subsp. lactis CCFM1274 produced relatively high levels of indole-3-carboxaldehyde (I3C). A mouse model of allergic asthma was established by oral administration of ovalbumin (OVA) and was subjected to oral administration of probiotics. The results demonstrated that treatment with CCFM1274 reduced the tendency for body weight loss and mortality in OVA-induced asthmatic mice. Ingestion of CCFM1274 improved the infiltration of perivascular and peribronchial inflammatory cells in the lung sections stained with hematoxylin and eosin (H&E). This outcome was accompanied by a reduction in the serum levels of OVA-specific immunoglobulin E (OVA-sIgE) and in the levels of IL-10 and IL-17 in the bronchoalveolar lavage fluid (BALF). The linear discriminant analysis effect size (LEfSe) of the gut microbiota showed that CCFM1274 increased the relative abundance of Bifidobacterium. In conclusion, CCFM1274 remodeled intestinal tryptophan metabolism in mice and contributed to the improvement of allergic asthma.

Effects of Family-Supported Healthcare on Children with Asthma

Introduction

Healthcare is essential for asthma control, however, whether family-supported healthcare improves therapeutic effects in childhood asthma remains unclear.

Methods

The enrolled patients were randomly divided into control and intervention groups. The pulmonary function was evaluated by forced expiratory volume in 1 s as a percentage of forced vital capacity (FEV1/FVC) and fractional exhaled nitric oxide (FeNO). Asthma control and life quality were assessed via a childhood asthma control test and pediatric asthma quality of life questionnaire. Inflammatory cytokines interleukin-6 (IL-6) and interleukin-17 (IL-17) were determined by enzyme-linked immunosorbent assay.

Results

No significant differences existed in the basic characteristics of asthma children and their parents among two groups. The increase of FEV1/FVC was higher in the intervention group versus the control group (76.47 ± 10.76% vs 69.76 ± 8.88%, p = 0.001 at the time of post-intervention), and the decrease of FeNO was greater in the intervention group (30.43 ± 6.85 bbp vs 35.64 ± 6.62 bbp, p = 0.003 at the time of post-intervention). Family-supported healthcare highly improved asthma control and quality of life in childhood asthma post-treatment. Meanwhile, the inflammatory cytokines IL-17 (118.14 ± 25.79 pg/mL in intervention group vs 142.86 ± 28.68 pg/mL in control group, p = 0.004 at the time of post-intervention) and IL-6 (103.76 ± 23.11 pg/mL in intervention group vs 119.73 ± 22.68 pg/mL in control group, p = 0.009 at the time of post-intervention) significantly decreased by family-supported healthcare intervention. Importantly, acute exacerbation (80.8% in intervention group vs 95.7% in control group, p = 0.030) and rehospitalization cases (88.5% in intervention group vs 100% in control group, p = 0.028) also decreased by family-supported healthcare intervention.

Discussion

Family-supported healthcare improves pulmonary function and quality of life while alleviates inflammation, acute exacerbation, and rehospitalization in childhood asthma post-routine treatment.

The Role of Exhaled Breath Condensate in Chronic Inflammatory and Neoplastic Diseases of the Respiratory Tract

Asthma and chronic obstructive pulmonary disease (COPD) are among the most common chronic respiratory diseases. Chronic inflammation of the airways leads to an increased production of inflammatory markers by the effector cells of the respiratory tract and lung tissue. These biomarkers allow the assessment of physiological and pathological processes and responses to therapeutic interventions. Lung cancer, which is characterized by high mortality, is one of the most frequently diagnosed cancers worldwide. Current screening methods and tissue biopsies have limitations that highlight the need for rapid diagnosis, patient differentiation, and effective management and monitoring. One promising non-invasive diagnostic method for respiratory diseases is the assessment of exhaled breath condensate (EBC). EBC contains a mixture of volatile and non-volatile biomarkers such as cytokines, leukotrienes, oxidative stress markers, and molecular biomarkers, providing significant information about inflammatory and neoplastic states in the lungs. This article summarizes the research on the application and development of EBC assessment in diagnosing and monitoring respiratory diseases, focusing on asthma, COPD, and lung cancer. The process of collecting condensate, potential issues, and selected groups of markers for detailed disease assessment in the future are discussed. Further research may contribute to the development of more precise and personalized diagnostic and treatment methods.

Exploring the Interplay between Asthma and Hemoglobinopathies: A Comprehensive Review

Asthma, a prevalent chronic respiratory condition characterized by inflammation of the airways and bronchoconstriction, has demonstrated a potential association with hemoglobinopathies such as thalassemia and sickle cell disease (SCD). Numerous studies have highlighted a higher prevalence of asthma among thalassemia patients compared to the general population, with rates ranging around 30%. Similarly, asthma frequently coexists with SCD, affecting approximately 20-48% of patients. Children with SCD often experience heightened lower airway obstruction and airway hyper-reactivity. Notably, the presence of asthma in SCD exacerbates respiratory symptoms and increases the risk of severe complications like acute chest syndrome, stroke, vaso-occlusive episodes, and early mortality. Several studies have noted a decrease in various cytokines such as IFN-γ and IL-10, along with higher levels of both IL-6 and IL-8, suggesting an overactivation of pro-inflammatory mechanisms in patients with hemoglobinopathies, which could trigger inflammatory conditions such as asthma. The exact mechanisms driving this association are better elucidated but may involve factors such as chronic inflammation, oxidative stress, and immune dysregulation associated with thalassemia-related complications like chronic hemolytic anemia and iron overload. This review aims to comprehensively analyze the relationship between asthma and hemoglobinopathies, with a focus on thalassemia and SCD. It emphasizes the importance of interdisciplinary collaboration among pulmonologists, hematologists, and other healthcare professionals to effectively manage this complex interplay. Understanding this link is crucial for improving care and outcomes in affected individuals.

Hydrangea serrata extract attenuates PM-exacerbated airway inflammation in the CARAS model by modulating the IL-33/ST2/NF-κB signaling pathway

Particulate matter (PM) significantly contributes to the global health crisis of respiratory diseases. It is known to induce and exacerbate conditions such as asthma and respiratory infections. Long exposure to PM can increase the risk of combined allergic rhinitis and asthma syndrome (CARAS). Although therapeutic drugs can be used to improve symptoms of respiratory diseases caused by PM, their usage is often accompanied by side effects. Therefore, many studies are being conducted to discover functional food materials that can more effectively treat respiratory diseases while minimizing the side effects of these therapeutic drugs. This study was conducted to investigate the efficacy of Hydrangea serrata extract (HSE) in airway inflammation in a mouse model of CARAS exacerbated by PM. In the CARAS mouse model worsened by PM, the airway inflammation improvement effect of HSE was evaluated by analyzing allergic nasal symptoms, changes in inflammatory cells, OVA-specific immunoglobulin (Ig) levels, cytokines, mast cell activation, and histopathological findings of both nasal mucosa and lung tissue. HSE effectively reduced OVA-specific IgE and IgG1 and inhibited the production of T helper type 2 (Th2)-related cytokines such as IL-4 and IL-5. Importantly, HSE reduced IL-33 and ST2 expression and inhibited the activation of the NF-κB signaling pathway. In addition, HSE inhibited airway hypersensitivity, mucus production, and inflammatory cell infiltration. These results suggest that HSE may inhibit airway inflammation in CARAS/PM mice by regulating the IL-33/ST2/NF-κB signaling pathway, opening avenues for considering HSE as a potential material for treating allergic airway inflammation diseases in the future.

The Evolution of Scientific Knowledge in Childhood Asthma over Time: A Surprising History

Asthma is a disease that has been described since the times of Hammurabi. However, it is only since the 1960s that effective therapeutic strategies have been available. Pathogenic mechanisms underlying the disease have been deeply studied, contributing to creating a "patient-specific asthma" definition. Biological drugs have been approved over the last twenty years, improving disease management in patients with severe asthma via a "precision medicine-driven approach". This article aims to describe the evolution of scientific knowledge in childhood asthma, focusing on the most recent biological therapies and their indications for patients with severe asthma.

Characteristics of Allergic, Eosinophilic, and Overlapping Asthma Phenotypes Among Pediatric Patients with Current Asthma: A Cross-Sectional Study from Saudi Arabia

Purpose

Asthma is one of the most common chronic diseases affecting 10%-30% of children in Saudi Arabia. Although data exist on adult asthma phenotyping and endotyping in Saudi Arabia, little is known about asthma phenotypes in Saudi children.

Patients and Methods

This cross-sectional study enrolled pediatric patients diagnosed with bronchial asthma and followed in the pediatric pulmonology clinic of the Abha Maternity and Children Hospital between August 2021 and May 2023.

Results

A total of 321 children (aged 5-14 years) were analyzed. The population was classified into allergic [169 (52.6%)], eosinophilic [144 (44.9%)], and overlapping allergic and eosinophilic asthma [97 (30.2%)] phenotypes. Regarding asthma severity, 35.5%, 50.2%, and 14.3% were classified as mild, moderate, and severe, respectively. Of the 321 patients in the study, 124 (38.6%) had at least one asthma exacerbation that required hospitalization. The number of reported missed school days in the previous year was 1571 days [190 (59.2%) patients reported at least one missed school day]. The factors associated with the likelihood of uncontrolled asthma for all study participants included: emergency room (ER) visit last year (OR = 3.7, 95% CI:0.6-15.9]), overlapping eosinophilic and allergic (OR = 3.2, 95% CI = 1.8-5.9), and allergic phenotype (OR = 2.7, 95% CI = 1.3-5.4). The level of asthma control differed significantly among the three asthma phenotypes (p = 0.037).

Conclusion

Allergic asthma is the most prevalent asthma phenotype in this study, followed by the eosinophilic phenotype. The research has also shown that several factors predict uncontrolled asthma, including a family history of asthma, previous admission to the PICU, and previous hospitalization ever. There is, therefore, a definite need for multicenter cohort studies to better understand the phenotypes and endotypes of childhood asthma, as it could offer therapeutic and prognostic relevance.

Eosinophil-derived neurotoxin levels in early childhood and association with preschool asthma - A prospective observational study

INTRODUCTION

Eosinophil-derived neurotoxin (EDN) is related to childhood asthma, while normal values are lacking. We aimed to document serum EDN levels at 1 and 3 years in general and in non-atopic children, and explore if EDN levels differed by sex or were associated with preschool asthma at 3 years.

METHODS

From the PreventADALL birth cohort, we included 1233 children with EDN analysed using ImmunoCAP at 1 and/or 3 years. Non-atopic children had no history of wheeze, asthma, allergic sensitization or atopic dermatitis. Preschool asthma was defined as having ≥3 episodes of bronchial obstruction between 2 and 3 years, plus doctor diagnosed asthma and/or asthma medication use by 3 years. The upper limit of normal (ULN) of EDN was defined as the 95th percentile. With Youden Index we calculated EDN cut-off levels for risk of preschool asthma.

RESULTS

The overall median (ULN) EDN levels were 27.4 (121) μg/L at 1 year (n = 787), and 20.1 (87.8) μg/L at 3 years (n = 857). Non-atopic children had EDN levels of 24.0 (107) μg/L at 1 year (n = 147), and 17.3 (84.6) μg/L at 3 years (n = 173). EDN levels were higher in boys compared to girls; 32.0 (133) versus 24.5 (97.0) μg/L at 1 year, and 20.9 (96.3) versus 19.0 (72.4) μg/L at 3 years. Preschool asthma was observed in 109/892 (12.2%) children. Higher EDN levels at 1 (>26.7 μg/L) and 3 (≥20.5 μg/L) years were associated with preschool asthma; adjusted OR (95% CI) 2.20 (1.09, 4.41) and 4.68 (2.29, 9.55), respectively.

CONCLUSION AND CLINICAL RELEVANCE

We report EDN values in early childhood, demonstrating higher levels at 1 compared to 3 years and in boys compared to girls at both ages. Higher EDN levels at both ages were associated with preschool asthma. However, EDN cut-off levels for preschool asthma were overall lower than the ULN of non-atopic children, limiting translation into clinical practice.

Unanswered questions on the use of biologics in pediatric asthma

The emergence of biologic therapies for the management of asthma has been a revolutionary change in our capacity to manage this disease. Since the launch of omalizumab, several other biologics have been marketed or are close to being marketed, suggesting that a plethora of monoclonal antibodies can be expected in the coming years. This will facilitate the transition to the paradigm of personalized medicine, but on the other hand will decisively further complicate the choice of the most appropriate treatment, in the absence of reliable enough biological markers. For these reasons, along with the relatively short time of use with these treatments, there are recurrently arising questions for which there are not even moderately documented answers, and for which the only solution must be based, with all reservations, on the combination of indirect evidence and expertise. In this paper, we attempt to address such questions, providing relevant commentaries and considering the whole width of the evidence base.

2022 Year in Review: Pediatric Asthma

Asthma is the most common chronic disease in children. Asthma is a heterogeneous disease characterized by variable, reversible airway obstruction and hyper-responsive airways. There is a high economic burden due to a child having poorly controlled asthma with one or more asthma exacerbations resulting in an emergency department visit or hospitalization in a year. Publications on diagnosis, treatment, and management of pediatric asthma are ongoing with over 2,549 papers published from January-November 2022. The intent of this paper is to summarize 8 key topics that have prompted discussions with local, regional, and national asthma experts due to a shift in clinical practice or lessons learned from the recent pandemic that may have future application.

Severe Asthma and Biological Therapies: Now and the Future

Recognition of phenotypic variability in pediatric asthma allows for a more personalized therapeutic approach. Knowledge of the underlying pathophysiological and molecular mechanisms (endotypes) of corresponding biomarkers and new treatments enables this strategy to progress. Biologic therapies for children with severe asthma are becoming more relevant in this sense. The T2 phenotype is the most prevalent in childhood and adolescence, and non-T2 phenotypes are usually rare. This document aims to review the mechanism of action, efficacy, and potential predictive and monitoring biomarkers of biological drugs, focusing on the pediatric population. The drugs currently available are omalizumab, mepolizumab, benralizumab, dupilumab, and 1ezepelumab, with some differences in administrative approval prescription criteria between the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Previously, we described the characteristics of severe asthma in children and its diagnostic and therapeutic management.

Ιnterleukin-17A-Enriched Neutrophil Extracellular Traps Promote Immunofibrotic Aspects of Childhood Asthma Exacerbation

Childhood asthma is a chronic inflammatory airway disorder that can drive tissue remodeling. Neutrophils are amongst the most prominent inflammatory cells contributing to disease manifestations and may exert a potent role in the progression of inflammation to fibrosis. However, their role in asthma exacerbation is still understudied. Here, we investigate the association between neutrophil extracellular traps (NETs) and lung fibroblasts in childhood asthma pathophysiology using serum samples from pediatric patients during asthma exacerbation. Cell-based assays and NETs/human fetal lung fibroblast co-cultures were deployed. Increased levels of NETs and interleukin (IL)-17A were detected in the sera of children during asthma exacerbation. The in vitro stimulation of control neutrophils using the sera from pediatric patients during asthma exacerbation resulted in IL-17A-enriched NET formation. The subsequent co-incubation of lung fibroblasts with in vitro-generated IL-17A-enriched NETs led fibroblasts to acquire a pre-fibrotic phenotype, as assessed via enhanced CCN2 expression, migratory/healing capacity, and collagen release. These data uncover the important pathogenic role of the NET/IL-17A axis in asthma exacerbation, linking lung inflammation to fibroblast dysfunction and fibrosis.

Association of selected inflammatory biomarkers with cough reflex sensitivity in asthmatic children

Bronchial asthma is the most common chronic respiratory disease of childhood. Cough is one of its defining symptoms. This study investigated the associations between selected inflammatory biomarkers and cough reflex sensitivity after capsaicin inhalation in children with mild and moderate well-controlled type 2 endotype asthma compared with non-asthmatic probands. Sensitivity to the cough reflex was measured by recording the cough response after capsaicin inhalation. The sandwich ELISA method was used to measure serum concentrations of the investigated potential inflammatory biomarkers (interleukin 13, interleukin 1beta, eosinophil-derived neurotoxin). The acquired data were statistically evaluated according to descriptive analyses for summarization and comparison between cough reflex sensitivity parameters and individual biomarker values in the observed and control groups modeled by a simple linear regression model. Statistical significance was defined as p<0.05. We showed a statistically significant association (p-value 0.03) between cough reflex sensitivity - C2 value (capsaicin concentration required for two cough responses) and interleukin 1beta serum concentrations in the asthma group compared with the control group of non-asthmatic children. Our results support the possibility of interleukin 1beta as a potential additive inflammatory biomarker used in clinical practice in children with asthma because of its correlation with the activity of the afferent nerve endings in the airways.

Severe pediatric asthma endotypes: current limits and future perspectives

INTRODUCTION

Although rare, pediatric severe therapy-resistant asthma (STRA) is a highly heterogeneous, resource-demanding disease that differs significantly from severe adult asthma and whose pathogenesis is still poorly understood.

AREAS COVERED

This review summarizes the latest 10 years of English-written studies defining pediatric STRA endotypes using lung-specific techniques such as bronchoalveolar lavage and endobronchial biopsy. Results of the studies and limits on the field are discussed, together with some future perspectives.

EXPERT OPINION

Over the years, it has become increasingly clear that 'one size does not fit all" in asthma. However, "Does an extremely tailored size fit more than one?'. Only using multicentric, longitudinal pediatric studies, will we be able to answer. Three issues could be particularly critical for future research. First, to provide, if existing, a distinction between prepuberal STRA and puberal STRA endotypes to understand the transition from pediatric to adult STRA and to design effective, tailored therapies in adolescents, usually suffering from poorer asthma control. Second, design early treatments for pediatric airway remodeling to preserve lifelong good lung function. Finally, to better characterize inflammation before and during biological therapies, to provide clues on whether to stop or change treatments.

Diagnostic value of IL-6 for patients with asthma: a meta-analysis

BACKGROUND

IL-6 is a pleotropic cytokine that acts as a pro-inflammatory mediator and acute-phase response inducer, but has also been reported to possess anti-inflammatory properties. The objective of this study was to assess the validity of serum IL-6 test for diagnosis of asthma.

METHODS

A literature search was conducted using PubMed, Embase, and Cochrane library from January 2007 to March 2021 to identify relevant studies. Eleven studies were included in this analysis, involving 1977 patients with asthma and 1591 healthy non-asthmatic controls. The meta-analysis was performed using Review Manager 5.3 software and Stata 16.0. Random effect model or fixed effect model (FEM) was used to estimate the standardized mean differences (SMDs) with 95% confidence intervals (CIs).

RESULTS

The meta-analysis results revealed that the serum IL-6 levels were higher in asthmatic patients than healthy non-asthmatic controls (SMD 1.31, 95% CI 0.82-1.81, P < 0.00001). IL-6 levels are significantly elevated in pediatric patients with asthma (SMD 1.58, 95% CI 0.75-2.41, P = 0.0002) and mildly elevated in adult patients with asthma (SMD 1.08, 95% CI 0.27-1.90, P = 0.009). In addition, a subgroup analysis of asthma disease status showed that IL-6 levels were increased in stable (SMD 0.69, 95% CI 0.28-1.09, P = 0.009) and exacerbation asthma (SMD 2.15, 95% CI 1.79-2.52, P < 0.00001) patients.

CONCLUSION

The results of this meta-analysis suggest that serum IL-6 levels were significantly elevated in asthmatic patients as compared to normal population. IL-6 levels can be used as an auxiliary indicator to distinguish individuals with asthma from healthy non-asthmatic controls.

Asthma control and care among six public health clinic attenders in Malaysia: A cross-sectional study

Background and Aims

Asthma is common in Malaysia but neglected. Achieving optimal asthma control and care is a challenge in the primary care setting. In this study, we aimed to identify the risk factors for poor asthma control and pattern of care among adults and children (5-17 years old) with asthma attending six public health clinics in Klang District, Malaysia.

Methods

We conducted a cross-sectional study collecting patients' sociodemographic characteristics, asthma control, trigger factors, healthcare use, asthma treatment, and monitoring and use of asthma action plan. Descriptive statistics and stepwise logistic regression were used in data analysis.

Results

A total of 1280 patients were recruited; 85.3% adults and 14.7% children aged 5-17 years old. Only 34.1% of adults had well-controlled asthma, 36.5% had partly controlled asthma, and 29.4% had uncontrolled asthma. In children, 54.3% had well-controlled asthma, 31.9% had partly controlled, and 13.8% had uncontrolled asthma. More than half had experienced one or more exacerbations in the last 1 year, with a mean of six exacerbations in adults and three in children. Main triggers for poor control in adults were haze (odds ratio [OR] 1.51; 95% confidence interval [CI] 1.13-2.01); cold food (OR 1.54; 95% CI 1.15-2.07), extreme emotion (OR 1.90; 95% CI 1.26-2.89); air-conditioning (OR 1.63; 95% CI 1.20-2.22); and physical activity (OR 2.85; 95% CI 2.13-3.82). In children, hot weather (OR 3.14; 95% CI 1.22-8.11), and allergic rhinitis (OR 2.57; 95% CI 1.13-5.82) contributed to poor control. The majority (81.7% of adults and 64.4% of children) were prescribed controller medications, but only 42.4% and 29.8% of the respective groups were compliant with the treatment. The importance of an asthma action plan was reported less emphasized in asthma education.

Conclusion

Asthma control remains suboptimal. Several triggers, compliance to controller medications, and asthma action plan use require attention during asthma reviews for better asthma outcomes.

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

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

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.

Applying the new guidelines to asthma management in children

PURPOSE OF REVIEW

This review aims to provide paediatricians with novel concepts from scientific evidence applicable to treating children with asthma. The latest guideline updates on paediatric asthma are discussed here, with a focus on the 2022 update of the GINA document.

RECENT FINDINGS

Mild asthma remains to be an important challenge for the paediatrician, and the introduction of new evidence-based treatment strategies, particularly those symptom-driven, could have a significant impact on the paediatric population. The identification of predictive biomarkers, the definition of biological treatment response, the possible duration of these therapies in this age group, as well as their potential action on airway remodelling are desirable in the short term. As the number of available biological treatment options expands, paediatricians should be supported by further evidence in decision-making.

SUMMARY

There is an urgent need to implement at multiple levels the latest therapeutic strategies proposed for asthma at all severities.

Dupilumab pharmacokinetics and effect on type 2 biomarkers in children with moderate-to-severe asthma

BACKGROUND

Type 2 inflammation is common in children with asthma. Dupilumab, a human antibody, blocks signaling of interleukin-4/-13, key and central drivers of type 2 inflammation. In the VOYAGE (NCT02948959) study, dupilumab reduced severe asthma exacerbations and improved lung function in children aged 6-11 years with uncontrolled, moderate-to-severe asthma.

OBJECTIVE

To assess pharmacokinetics of dupilumab and type 2 biomarker changes in children with type 2 asthma in VOYAGE.

METHODS

Patients were randomized to dupilumab 100 mg (≤30 kg) or 200 mg (>30 kg) or placebo every 2 weeks (q2w) for 52 weeks. Dupilumab concentrations and changes in type 2 biomarkers were assessed at each visit.

RESULTS

Dupilumab concentrations in serum reached steady state by Week 12, with mean concentrations of 51.2 mg/L and 79.4 mg/L in children receiving dupilumab 100 mg q2w and 200 mg q2w, respectively (therapeutic range in adults and adolescents: 29-80 mg/L). Reductions in type 2 biomarkers were comparable between regimens, and greater in patients treated with dupilumab vs placebo. In children treated with dupilumab 100 mg and 200 mg q2w, median percent changes (Q1, Q3) from baseline at Week 52 were, respectively, -78.6% (-86.3, -69.80) and -78.6% (-84.9, -70.1) for serum total IgE, -53.6% (-66.4, -34.6) and -43.7% (-58.6, -28.5) for TARC, -25.7% (-60.0, 27.6) and -33.3% (-60.6, 16.6) for blood eosinophils, and -47.7% (-73.8, 18.9) and -55.6% (-73.6, -20.0) for FeNO.

CONCLUSION

Weight-tiered dose regimens achieved mean concentrations within the dupilumab therapeutic range. Median decreases in type 2 biomarker levels were similar between dose regimens.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02948959.

Severe pediatric asthma therapy: Omalizumab-A systematic review and meta-analysis of efficacy and safety profile

Background

Omalizumab is the first biological therapy used to treat moderate-to-severe asthma and certainly the one with the highest number of publications.

Methods

A systematic review and meta-analysis were performed to examine two critical outcomes of omalizumab therapy, asthma exacerbation rate, the reduction of the use of inhaled corticosteroids (ICS), and the improvement of the lung function as a secondary outcome using the following keywords in the MEDLINE database: "anti-IgE, severe asthma, children, and randomized controlled trial." We specifically selected papers that included moderate-to-severe asthma patients and collected data on children and adolescents.

Results

Four RCT studies (total number of patients = 1,239) were included in the analysis. The reported data on exacerbations showed an overall improvement in the exacerbation rate with a decreased use of inhaled steroids and some other minimal clinically important difference (MCID).

Conclusions

Our systematic review confirms the known findings that omalizumab therapy decreases asthma exacerbation rate and reduces background therapy inhaled steroid dose. Therefore, add-on therapy with omalizumab shows a good efficacy and safety profile, thus proving to be a useful additional therapeutic option.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42023396785.

Clinical Potential of Eosinophil-Derived Neurotoxin in Asthma Management

The assessment and management of patients with asthma is challenging because of the complexity of the underlying inflammatory mechanisms and heterogeneity of their clinical presentation. Optimizing disease management requires therapy individualization that should rely on reliable biomarkers to unravel the phenotypes and endotypes of asthma. The secretory activity and turnover of eosinophils, as assessed by measuring eosinophil-derived proteins, may provide an accurate and complementary tool that mirrors the eosinophil activation status. Emerging evidence suggests that eosinophil-derived neurotoxin has considerable potential as a precision medicine biomarker. In this review, we explore the suitability of eosinophil-derived neurotoxin as a biomarker in asthma management, with particular emphasis on its clinical significance in the management of both pediatric and adult populations.

Application of Metabolomics in Obesity-Related Childhood Asthma Subtyping: A Narrative Scoping Review

Obesity-related asthma is a heterogeneous childhood asthma phenotype with rising prevalence. Observational studies identify early-life obesity or weight gain as risk factors for childhood asthma development. The reverse association is also described, children with asthma have a higher risk of being obese. Obese children with asthma have poor symptom control and an increased number of asthma attacks compared to non-obese children with asthma. Clinical trials have also identified that a proportion of obese children with asthma do not respond as well to usual treatment (e.g., inhaled corticosteroids). The heterogeneity of obesity-related asthma phenotypes may be attributable to different underlying pathogenetic mechanisms. Although few childhood obesity-related asthma endotypes have been described, our knowledge in this field is incomplete. An evolving analytical profiling technique, metabolomics, has the potential to link individuals' genetic backgrounds and environmental exposures (e.g., diet) to disease endotypes. This will ultimately help define clinically relevant obesity-related childhood asthma subtypes that respond better to targeted treatment. However, there are challenges related to this approach. The current narrative scoping review summarizes the evidence for metabolomics contributing to asthma subtyping in obese children, highlights the challenges associated with the implementation of this approach, and identifies gaps in research.

Immunoglobulin E and G autoantibodies against eosinophil proteins in children and adults with asthma and healthy subjects

Background

Autoimmune IgG response has been described in the pathogenesis of asthma in adults, but IgE autoimmunity has been little explored. Considering high levels of blood eosinophils and immunoglobulin E in asthmatic patients, the possibility of IgE autoantibody response to eosinophil proteins arises.

Objective

To explore the presence of IgE and IgG autoantibodies against Eosinophil peroxidase (EPX) and Eosinophil cationic protein (ECP).

Methods

Three steps were followed: 1) The frequency of IgE and IgG autoantibodies against EPX and ECP was investigated among asthmatic and healthy subjects. 2) The ability of IgE autoantibodies to induce an inflammatory response (basophil activation) was performed. 3) The capacity of autoantibodies to identify patients with severe asthma was evaluated.

Results

Asthmatic and healthy subjects had IgE and IgG autoantibodies against EPX and ECP. Anti-EPX IgE was significantly higher in asthmatic patients. Severe asthmatic patients had a higher frequency and higher levels of IgE and IgG autoantibodies compared to healthy subjects. There was not a correlation between autoantibodies and blood eosinophils. Children younger than 14 years of age had IgE and IgG autoantibodies against to EPX and ECP. IgE autoantibodies to EPX and ECP induced basophil activation in asthmatic patients.

Conclusion

In this study, we identify for the first time IgE autoantibodies against EPX and ECP in adults and children patients with asthma; IgE and IgG autoantibodies against EPX and ECP could serve as a predictive biomarker of the clinical severity.

Analysis of Differentially Expressed MicroRNAs in Serum and Lung Tissues from Individuals with Severe Asthma Treated with Oral Glucocorticoids

Nowadays, microRNAs (miRNAs) are increasingly used as biomarkers due to their potential contribution to the diagnosis and targeted treatment of a range of diseases. The aim of the study was to analyze the miRNA expression profiles in serum and lung tissue from patients with severe asthma treated with oral corticosteroids (OCS) and those without OCS treatment. For this purpose, serum and lung tissue miRNAs of OCS and non-OCS asthmatic individuals were evaluated by miRNAs-Seq, and subsequently miRNA validation was performed using RT-qPCR. Additionally, pathway enrichment analysis of deregulated miRNAs was conducted. We observed altered expression by the next-generation sequencing (NGS) of 11 miRNAs in serum, of which five (hsa-miR-148b-3p, hsa-miR-221-5p, hsa-miR-618, hsa-miR-941, and hsa-miR-769-5p) were validated by RT-qPCR, and three miRNAs in lung tissue (hsa-miR-144-3p, hsa-miR-144-5p, and hsa-miR-451a). The best multivariate logistic regression model to differentiate individuals with severe asthma, treated and untreated with OCS, was to combine the serum miRNAs hsa-miR-221-5p and hsa-miR-769-5p. Expression of hsa-miR-148b-3p and hsa-miR-221-5p correlated with FEV1/FVC (%) and these altered miRNAs act in key signaling pathways for asthma disease and the regulated expression of some genes (FOXO3, PTEN, and MAPK3) involved in these pathways. In conclusion, there are miRNA profiles differentially expressed in OCS-treated individuals with asthma and could be used as biomarkers of OCS treatment.

THE LEVEL OF REACTIVE OXYGEN SPECIES AS A MARKER OF ASTHMA SEVERITY IN CHILDREN

OBJECTIVE

The aim of the research was to assess the reactive oxygen species (ROS) levels in granulocytes of patients with asthma.

PATIENTS AND METHODS

Materials and methods: The study involved 35 children aged 5 to 17 years. 26 children with persistent asthma, partially controlled course in the period of exacerbation were divided into groups: 1 group - mild asthma (n = 12), group 2 - moderate asthma (n = 7) group 3 - severe asthma (n = 7) and control group included almost healthy children (n = 9). ROS levels in granulocytes were evaluated using BD FACSDiva™. The spirographic complex was used to assess the function of external respiration.

RESULTS

Results: The level of ROS in granulocytes of patients with severe asthma was significantly reduced compared with children in the control group and patients with mild and moderate asthma (p₁-₃ = 0.0003, p₂-₃ = 0.0017, p c-₃ = 0.0150). The concentration of ROS in granulocytes ≤ 285 a.u. was prognostically significant with high specificity and sensitivity with severe asthma.

CONCLUSION

Conclusions: The concentration of ROS levels in neutrophils in patients with severe asthma probably reflected the suppression of their products, which suggests the depletion of the reserve capacity of neutrophils. Decreased concentrations of reactive oxygen species in children with asthma can be considered as a possible marker of asthma severity.

Challenges in the Pharmacotherapeutic Management of Pediatric Asthma

Bronchial asthma is one of the most common chronic conditions in pediatric practice, with increasing prevalence hampered by poor socioeconomic impacts, leading to major public health issues. Considered as a complex heterogeneous syndrome, not a single disease, the management of the disease is a real challenge, impacting medical staff, patients and caregivers. Over the decades, a significant number of diagnostic and treatment regimen have been developed to achieve good standards, sustaining balanced control of the disease. This paper attempts a review on the establishment of new trends in the management of bronchial asthma in the pediatric age group.

Utility of biomarkers in the diagnosis and monitoring of asthmatic children

Asthma imposes a heavy morbidity burden during childhood; it affects over 10% of children in Europe and North America and it is estimated to exceed 400 million people worldwide by the year 2025. In clinical practice, diagnosis of asthma in children is mostly based on clinical criteria; nevertheless, assessment of both physiological and pathological processes through biomarkers, support asthma diagnosis, aid monitoring, and further lead to better treatment outcomes and reduced morbidity. Recently, identification and validation of biomarkers in pediatric asthma has emerged as a top priority across leading experts, researchers, and clinicians. Moreover, the implementation of non-invasive biomarkers for the assessment and monitoring of paediatric patients with asthma, has been prioritized; however, only a proportion of them are currently included in the clinical practise. Although, the use of non-invasive biomarkers is highly supported in recent asthma guidelines for documenting diagnosis and supporting monitoring of asthmatic patients, data on the Pediatric population are limited. In the present report, the Pediatric Asthma Committee of the World Allergy Organization (WAO), aims to summarize and discuss available data for the implementation of non-invasive biomarkers in the diagnosis and monitoring in children with asthma. Information on the most studied biomarkers, including spirometry, oscillometry, markers of allergic sensitization, fractional exhaled nitric oxide, and the most recent exhaled breath markers and "omic" approaches, will be reviewed. Practical limitations and considerations based on both experts' opinion and critical review of the literature, on the utility of all "well-known" and newly introduced non-invasive biomarkers will be presented. A critical commentary on biomarkers' use in diagnosing and monitoring asthma during the COVID-19 pandemic, cost and availability of biomarkers in different settings and in developing countries, the differences on the biomarkers use between Primary Practitioners, Pediatricians, and Specialists and their role on the longitudinal aspect of asthma is provided.

Cytokine profile in childhood asthma

Childhood asthma is a chronic airway disease, which pathogenesis is markedly heterogeneous–with multiple phenotypes defining visible characteristics and endotypes defining molecular mechanisms. Cytokines and chemokines released during inflammatory responses are key immune mediators. The cytokine response can largely determine the susceptibility to childhood asthma and its severity. The purpose of this study was to characterize the immune profile of childhood asthma. The study involved 26 children (3–18 years old), who were divided into 2 groups: study–with childhood asthma; control–without asthma. The innovative Bio-Plex method was used to determine the serum concentration of 37 inflammatory proteins in one experiment. The results were analyzed using univariate statistical tests. In the study group, the level of the 10 tested markers increased, while the level of the remaining 9 decreased compared to the control; a statistically significant reduction in concentration was obtained only for the MMP-1(p<0.05). According to the ROC curve, MMP-1 can be considered an effective discriminator of childhood asthma (p<0.05; AUC=0.752). Cytokines/chemokines may be useful in the diagnosis of childhood asthma and may also become a prognostic target in determining the phenotype/endotype of this condition. This study should be a prelude to and an incentive for more complex proteomic analyzes.

Identification of Hub Genes and Potential Biomarkers for Childhood Asthma by Utilizing an Established Bioinformatic Analysis Approach

Childhood asthma represents a heterogeneous disease resulting from the interaction between genetic factors and environmental exposures. Currently, finding reliable biomarkers is necessary for the clinical management of childhood asthma. However, only a few biomarkers are being used in clinical practice in the pediatric population. In the long run, new biomarkers for asthma in children are required and would help direct therapy approaches. This study aims to identify potential childhood asthma biomarkers using a genetic-driven biomarkers approach. Herein, childhood asthma-associated Single Nucleotide Polymorphisms (SNPs) were utilized from the GWAS database to drive and facilitate the biomarker of childhood asthma. We uncovered 466 childhood asthma-associated loci by extending to proximal SNPs based on r2 > 0.8 in Asian populations and utilizing HaploReg version 4.1 to determine 393 childhood asthma risk genes. Next, the functional roles of these genes were subsequently investigated using Gene Ontology (GO) term enrichment analysis, a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and a protein−protein interaction (PPI) network. MCODE and CytoHubba are two Cytoscape plugins utilized to find biomarker genes from functional networks created using childhood asthma risk genes. Intriguingly, 10 hub genes (IL6, IL4, IL2, IL13, PTPRC, IL5, IL33, TBX21, IL2RA, and STAT6) were successfully identified and may have been identified to play a potential role in the pathogenesis of childhood asthma. Among 10 hub genes, we strongly suggest IL6 and IL4 as prospective childhood asthma biomarkers since both of these biomarkers achieved a high systemic score in Cytohubba’s MCC algorithm. In summary, this study offers a valuable genetic-driven biomarker approach to facilitate the potential biomarkers for asthma in children.

Novel Lung Growth Strategy with Biological Therapy Targeting Airway Remodeling in Childhood Bronchial Asthma

Anti-inflammatory therapy, centered on inhaled steroids, suppresses airway inflammation in asthma, reduces asthma mortality and hospitalization rates, and achieves clinical remission in many pediatric patients. However, the spontaneous remission rate of childhood asthma in adulthood is not high, and airway inflammation and airway remodeling persist after remission of asthma symptoms. Childhood asthma impairs normal lung maturation, interferes with peak lung function in adolescence, reduces lung function in adulthood, and increases the risk of developing chronic obstructive pulmonary disease (COPD). Early suppression of airway inflammation in childhood and prevention of asthma exacerbations may improve lung maturation, leading to good lung function and prevention of adult COPD. Biological drugs that target T-helper 2 (Th2) cytokines are used in patients with severe pediatric asthma to reduce exacerbations and airway inflammation and improve respiratory function. They may also suppress airway remodeling in childhood and prevent respiratory deterioration in adulthood, reducing the risk of COPD and improving long-term prognosis. No studies have demonstrated a suppressive effect on airway remodeling in childhood severe asthma, and further clinical trials using airway imaging analysis are needed to ascertain the inhibitory effect of biological drugs on airway remodeling in severe childhood asthma. In this review, we describe the natural prognosis of lung function in childhood asthma and the risk of developing adult COPD, the pathophysiology of allergic airway inflammation and airway remodeling via Th2 cytokines, and the inhibitory effect of biological drugs on airway remodeling in childhood asthma.

Omalizumab for the treatment of severe allergic asthma in children: A tale of two

Omalizumab is a monoclonal antibody which targets immunoglobulin E. It is approved as an add-on therapy for children with severe allergic asthma. Assessment of endotype and phenotype is necessary in order to correctly identify those patients who are most likely to respond to omalizumab. Children with severe asthma represent a complex heterogeneous group. This report outlines the background, management, and outcomes for two children initiated on omalizumab for severe allergic asthma in Children's Health Ireland at Tallaght. It demonstrates the difficulties faced by this cohort and the positive impact targeted biological therapy can have. Given the substantial cohort of children with asthma attending our tertiary center, it also indicates that comprehensive stepwise care can achieve adequate control in the vast majority of cases without the requirement for additional therapies.

Challenges in uncontrolled asthma in pediatrics: important considerations for the clinician

INTRODUCTION

Despite symptoms control being the primary focus of asthma management according to guidelines, uncontrolled asthma is still an issue worldwide, leading to huge costs and asthma deaths at all ages. In childhood, poor asthma control can be even more harmful, as it can irreversibly compromise the children's lung function and the whole family's well-being.

AREAS COVERED

Given the problem extent, this review aims to discuss the leading modifiable causes of uncontrolled asthma in Pediatrics, giving some practical insights regarding the critical role of families and the main tools for monitoring control and drug adherence, even at a distance. The most recent GINA documents were used as the primary reference, along with the latest evidence regarding the management of asthma control and the impact of the COVID-19 pandemic on asthma.

EXPERT OPINION

In managing pediatric asthma, a multidisciplinary, multi-determinant, personalized approach is needed, actively involving families, schools, and other specialists. In addition to current strategies for implementing control, electronic health strategies, new validated asthma control tools, and the identification of novel inflammatory biomarkers could lead to increasingly tailored therapies with greater effectiveness in reaching asthma control.

Biologic Therapies in Pediatric Asthma

Undeniably, childhood asthma is a multifactorial and heterogeneous chronic condition widespread in children. Its management, especially of the severe form refractory to standard therapy remains challenging. Over the past decades, the development of biologic agents and their subsequent approval has provided an advanced and very promising treatment alternative, eventually directing toward a successful precision medicine approach. The application of currently approved add-on treatments for severe asthma in children, namely omalizumab, mepolizumab, benralizumab, dupilumab, and tezepelumab have been shown to be effective in terms of asthma control and exacerbation rate. However, to date, information is still lacking regarding its long-term use. As a result, data are frequently extrapolated from adult studies. Thus, the selection of the appropriate biologic agent, the potential predictors of good asthma response, and the long-term outcome in the pediatric population are still to be further investigated. The aim of the present study was to provide an overview of the current status of the latest evidence about all licensed monoclonal antibodies (mAbs) that have emerged and been applied to the field of asthma management. The innovative future targets are also briefly discussed.

Role of Cellular Metabolism in the Formation of Neutrophil Extracellular Traps in Airway Diseases

Neutrophil extracellular traps (NETs) are a recently described mechanism of neutrophils that play an important role in health and disease. NETs are an innate defense mechanism that participate in clearance of pathogens, but they may also cause collateral damage in unrelated host tissues. Neutrophil dysregulation and NETosis occur in multiple lung diseases, such as pathogen-induced acute lung injury, pneumonia, chronic obstructive pulmonary disease (COPD), severe asthma, cystic fibrosis, and recently, the novel coronavirus SARS-CoV-2. More recently, research into immunometabolism has surged due to the possibility of reprogramming metabolism in order to modulate immune functions. The present review analyzes the different metabolic pathways associated with NETs formation, and how these impact on pathologies of the airways.

Severe bronchiolitis profiles and risk of asthma development in Finnish children

BACKGROUND

Recent studies support the existence of several entities under the clinical diagnosis of bronchiolitis. Among infants with severe bronchiolitis, distinct profiles have been differentially associated with development of recurrent wheezing by age 3 years. However, their associations with actual asthma remain unclear.

OBJECTIVE

Our aim was to study the association between severe bronchiolitis profiles identified by using a clustering approach and childhood asthma.

METHODS

Among 408 children (aged <2 years) hospitalized with bronchiolitis in Finland (in 2008-2010), latent class analysis identified 3 bronchiolitis profiles: profile A (47%), characterized by history of wheezing and/or eczema, wheezing during acute illness, and rhinovirus infection; profile BC (38%), characterized by severe illness and respiratory syncytial virus infection; and profile D (15%), characterized by the least severely ill children, including mostly children without wheezing and with rhinovirus infection. The children were followed by questionnaire 4 years later (86% [n = 348]) and through a nationwide social insurance database 7 years later (99% [n = 403]). Current asthma at the 4- and 7-year follow-ups was defined by regular use (according to parental report and medical records) or purchase (according to the social insurance database) of asthma control medication.

RESULTS

Compared with risk of current asthma associated with profile BC, we observed increased risk of current asthma associated with profile A both at the 4-year follow-up (age- and sex-adjusted odds ratio = 2.42 [95% CI = 1.23-4.75]) and at the 7-year follow-up (age- and sex-adjusted odds ratio = 3.14 [95% CI = 1.33-7.42]). No significant difference in asthma risk was observed between profile D and profile BC.

CONCLUSION

These longitudinal results provide further support for an association between a distinct severe bronchiolitis profile (characterized by a history of wheezing and/or eczema and rhinovirus infection) and risk of development childhood asthma.

Diagnosis and management of asthma in children

Asthma is the the most common chronic respiratory condition of childhood worldwide, with around 14% of children and young people affected. Despite the high prevalence, paediatric asthma outcomes are inadequate, and there are several avoidable deaths each year. Characteristic asthma features include wheeze, shortness of breath and cough, which are typically triggered by a number of possible stimuli. There are several diagnostic challenges, and as a result, both overdiagnosis and underdiagnosis of paediatric asthma remain problematic.Effective asthma management involves a holistic approach addressing both pharmacological and non-pharmacological management, as well as education and self-management aspects. Working in partnership with children and families is key in promoting good outcomes. Education on how to take treatment effectively, trigger avoidance, modifiable risk factors and actions to take during acute attacks via personalised asthma action plans is essential.This review aimed to provide an overview of good clinical practice in the diagnosis and management of paediatric asthma. We discuss the current diagnostic challenges and predictors of life-threatening attacks. Additionally, we outline the similarities and differences in global paediatric asthma guidelines and highlight potential future developments in care. It is hoped that this review will be useful for healthcare providers working in a range of child health settings.

Holy Grail: the journey towards disease modification in asthma

At present, there is no cure for asthma, and treatment typically involves therapies that prevent or reduce asthma symptoms, without modifying the underlying disease. A “disease-modifying” treatment can be classed as able to address the pathogenesis of a disease, preventing progression or leading to a long-term reduction in symptoms. Such therapies have been investigated and approved in other indications, e.g. rheumatoid arthritis and immunoglobulin E-mediated allergic disease. Asthma's heterogeneous nature has made the discovery of similar therapies in asthma more difficult, although novel therapies (e.g. biologics) may have the potential to exhibit disease-modifying properties. To investigate the disease-modifying potential of a treatment, study design considerations can be made, including: appropriate end-point selection, length of trial, age of study population (key differences between adults/children in physiology, pathology and drug metabolism) and comorbidities in the patient population. Potential future focus areas for disease-modifying treatments in asthma include early assessments (e.g. to detect patterns of remodelling) and interventions for patients genetically susceptible to asthma, interventions to prevent virally induced asthma and therapies to promote a healthy microbiome. This review explores the pathophysiology of asthma, the disease-modifying potential of current asthma therapies and the direction future research may take to achieve full disease remission or prevention.

Asthma is a complex, heterogeneous disease, which currently has no cure; this review explores the disease-modifying potential of asthma therapies and the direction future research may take to achieve disease remission or prevention.https://bit.ly/31AxYou

Allergen Management in Children with Type 2-High Asthma

Children exposed to various indoor and outdoor allergens are placed at an increased risk of developing asthma in later life, with sensitization in these individuals being a strong predictor of disease morbidity. In addition, aeroallergen exposure influences asthma outcomes through an interplay with adverse determinants of health. The goal of this review is to provide an introductory overview of factors related to aeroallergen exposure in type 2-high childhood asthma. These include the relevance of exposure in asthma exacerbations and severity, and the evidence-base for avoidance and treatment for sensitization to these allergens. This review will focus on both indoor aeroallergens (house dust mite, pet, cockroach, mold, and rodent) and outdoor aeroallergens (pollens and molds). Treatment of aeroallergen sensitization in children with asthma includes avoidance and removal measures, although there is limited evidence of clinical benefit especially with single-strategy approaches. We will also address the interplay of aeroallergens and climate change, adverse social determinants, and the current COVID-19 pandemic, when we have seen a dramatic reduction in asthma exacerbations and emergency department visits among children. While there are many factors that are hypothesized to contribute to this reduction, among them is a reduced exposure to outdoor seasonal aeroallergens.

MMEF25-75 may predict significant BDR and future risk of exacerbations in asthmatic children with normal baseline FEV1

(1) Background: Several recent studies on the clinical value of spirometry indexes demonstrated high sensitivity of FEF25-75 as a marker of bronchial obstruction in asthmatics with normal baseline spirometry. Our study aims to evaluate the clinical value of maximal mid-expiratory flow in children with asthma. (2) Methods: For two years, 257 children were included - 211 with asthma and 46 healthy controls. Pre- and post-bronchodilator spirometry, atopic status determination and asthma control assessment were performed. (3) Results: The small airway obstruction (SAO) group (FEV1≥80%, ММEF25/75<65%) demonstrated significantly lower values for FEV1, FEV1/FVC, PEFR, МMMF25/75 and a significant higher bronchodilator response (BDR, ΔFEV1% init. ≥12%) compared to normal baseline spirometry group (FEV1>80%, MMEF25/75≥65%) (Р<0.0001). In addition, we found a statistically significant difference in FEF25-75/FVC median between asthmatics and healthy controls (Р<0.0001) regardless of the FEV1 value. Children with SAO have a 2.338-fold higher risk of poor asthma outcome (OR 95% CI [1.077-5.294]) and a 6.171-fold (OR 95% CI [2.523-15.096]) greater probability of demonstrating positive BDR, compared to children with normal baseline spirometry. MMEF25/75 was found to be a good predictor for positive BDR with AUC 0.843 (CI 0.781-0.845) and a best cut-off value of 58.1% (77.8% sensitivity and 78.8% specificity). (4) Conclusion: Our results confirmed that a small but substantial group of asthmatic children with normal baseline FEV1 and low MMEF25-75 are at higher risk for poor asthma outcomes.

Perimenstrual Asthma in Adolescents: A Shared Condition in Pediatric and Gynecological Endocrinology

Asthma is a frequent medical condition in adolescence. The worsening of the most common symptoms perimenstrually is defined as perimenstrual asthma (PMA). The cause of PMA remains unclear, but a role for hormonal milieu is plausible. Data on PMA in adolescents are limited, and its management is not fully established. We aimed to discuss the PMA phenomenon in young females from pathophysiology to preventive strategies, focusing on the relationship with the hormonal pattern. The fluctuation of estrogens at ovulation and before menstruation and the progesterone secretion during the luteal phase and its subsequent withdrawal seem to be the culprits, because the deterioration of asthma is cyclical during the luteal phase and/or during the first days of the menstrual cycle. Conventional asthma therapies are not always effective for PMA. Preventive strategies may include innovative hormonal contraception. Even a possible beneficial effect of other hormonal treatments, including estrogens, progestogens, and androgens, as well as leukotriene receptor antagonists and explorative approach using microbial-directed therapy, is considered. The underlying mechanisms, through which sex-hormone fluctuations influence asthma symptoms, represent a challenge in the clinical management of such a distressing condition. Further studies focused on young females are mandatory to promote adolescent health.

Chronic rhinosinusitis with nasal polyps: how to identify eligible patients for biologics in clinical practice

Objective

This study compared three severity measures for chronic rhinosinusitis with nasal polyps (CRSwNP). The outcome was to identify patients who are eligible for biological therapy.

Methods

330 adult patients with CRSwNP were examined. Nasal polyp score (NPS), sinonasal outcome test (SNOT-22) and clinical-cytological grading (CCG) were compared. Clinical history, past surgery and asthma control test were also considered.

Results

Only 45 (13.6%) patients had a contextual positivity to the three severity measures. The concordance among tests was slight/fair. Patients with severe disease (all tests positive) had more impaired parameters. The mixed cytotype (OR = 4.07), nasal obstruction (OR = 10.06), post-nasal drip (OR = 1.98), embarrassment (OR = 2.53) and difficulty falling asleep (OR = 1.92) were significantly associated with severe CRSwNP.

Conclusions

To identify candidates for biological therapy, the contextual use of NPS, SNOT-22 and CCG is preferable. In this way, global assessment of CRSwNP, including morphology, inflammation, comorbidity, symptoms and quality of life is possible.

Severe Pediatric Asthma Therapy: Mepolizumab

There is a growing need for advanced treatment in children with persistent and severe asthma symptoms. As a matter of fact, between 2 and 5% of asthmatic children experience repeated hospitalizations and poor quality of life despite optimized treatment with inhaled glucocorticoid plus a second controller. In this scenario, mepolizumab, a humanized monoclonal antibody, has proven to be effective in controlling eosinophil proliferation by targeting interleukin-5 (IL-5), a key mediator of eosinophil activation pathways. Mepolizumab is approved since 2015 for adults at a monthly dose of 100 mg subcutaneously and it has been approved for patients ≥ 6 years of age in 2019. Especially in children aged 6 to 11 years, mepolizumab showed a greater bioavailability, with comparable pharmacodynamics parameters as in the adult population. The recommended dose of 40 mg every 4 weeks for children aged 6 through 11 years, and 100 mg for patients ≥ 12 years provides appropriate concentration and proved similar therapeutic effects as in the adult study group. A marked reduction in eosinophil counts clinically reflects a significant improvement in asthma control as demonstrated by validated questionnaires, reduction of exacerbation rates, and the number of hospitalizations. Finally, mepolizumab provides a safety and tolerability profile similar to that observed in adults with adverse events mostly of mild or moderate severity. The most common adverse events were headache and injection-site reaction. In conclusion, mepolizumab can be considered a safe and targeted step-up therapy for severe asthma with an eosinophilic phenotype in children and adolescents.

Sodium houttuynia alleviates airway inflammation in asthmatic mice by regulating FoxP3/RORγT expression and reversing Treg/Th17 cell imbalance

Synthetized from a natural oil of Houttuynia cordata, sodium houttuynia was reported to have anti-inflammatory effects. The present study aimed to investigate whether sodium houttuynia could alleviate the characteristic airway inflammation and Treg/Th17 cell imbalance of asthma in vivo. Experimental mice with neutrophilic asthma were injected with sodium houttuynia or dexamethasone (alone or in combination) intraperitoneally. The airway reactivity was measured, and bronchoalveolar lavage fluid was collected for cell count. Hematoxylin/eosin and periodic acid-Schiff staining were performed to assess pulmonary inflammation and mucus hypersecretion. Immunohistochemical analysis was conducted to determine the expression of IL-10, IL-17A, FoxP3, and RORγT in the lung tissue, and the serum levels of IL-10 and IL-17A were analyzed by ELISA. The proportion of CD4⁺CD25⁺FoxP3⁺ Treg and Th17 cells within the CD4⁺ T cell subset of splenocytes was analyzed by flow cytometry. FoxP3 and RORγT mRNA and protein expressions in the lung were analyzed by real-time PCR and western blot, respectively. Overall, sodium houttuynia was found to ameliorate the Treg/Th17 cell imbalance and reduce the airway inflammation, hyperresponsiveness, and mucus hypersecretion by increasing the frequency of CD4⁺CD25⁺FoxP3⁺ Treg cells and the secretion of IL-10, while decreasing the proportion of Th17 cells and IL-17A production. Although the regulatory effect of sodium houttuynia was not as good as that achieved with dexamethasone, combination of the two compounds showed improved inhibitory effects on airway hyperresponsiveness, inflammation, and mucus hypersecretion. Hence, sodium houttuynia may be beneficial for the treatment of asthma.

Thymic stromal lymphopoietin and alarmins as possible therapeutical targets for asthma

PURPOSE OF REVIEW

Overview of epithelial cytokines, particularly thymic stromal lymphopoietin (TSLP), released by the airway epithelium and the effects of their inhibition on the outcomes of patients with asthma.

RECENT FINDINGS

The epithelial cytokines are early mediators at the top of the inflammatory cascade and are attractive therapeutic targets to prevent exacerbations and improve lung function in patients with type 2 and nontype 2 asthma.

SUMMARY

Clinical trials demonstrated that tezepelumab, an anti-TSLP monoclonal antibody, is a promising alternative treatment for asthma that is effective also in nontype 2 asthma. The PATHWAY and NAVIGATOR trials have assessed its effects in improving outcomes on broad clinically diverse populations. The identification of biomarkers will help to predict potential responders and help in asthma treatment personalization.

Development of childhood asthma prediction models using machine learning approaches

BACKGROUND

Respiratory symptoms are common in early life and often transient. It is difficult to identify in which children these will persist and result in asthma. Machine learning (ML) approaches have the potential for better predictive performance and generalisability over existing childhood asthma prediction models. This study applied ML approaches to predict school-age asthma (age 10) in early life (Childhood Asthma Prediction in Early life, CAPE model) and at preschool age (Childhood Asthma Prediction at Preschool age, CAPP model).

METHODS

Clinical and environmental exposure data was collected from children enrolled in the Isle of Wight Birth Cohort (N = 1368, ∼15% asthma prevalence). Recursive Feature Elimination (RFE) identified an optimal subset of features predictive of school-age asthma for each model. Seven state-of-the-art ML classification algorithms were used to develop prognostic models. Training was performed by applying fivefold cross-validation, imputation, and resampling. Predictive performance was evaluated on the test set. Models were further externally validated in the Manchester Asthma and Allergy Study (MAAS) cohort.

RESULTS

RFE identified eight and twelve predictors for the CAPE and CAPP models, respectively. Support Vector Machine (SVM) algorithms provided the best performance for both the CAPE (area under the receiver operating characteristic curve, AUC = 0.71) and CAPP (AUC = 0.82) models. Both models demonstrated good generalisability in MAAS (CAPE 8-year = 0.71, 11-year = 0.71, CAPP 8-year = 0.83, 11-year = 0.79) and excellent sensitivity to predict a subgroup of persistent wheezers.

CONCLUSION

Using ML approaches improved upon the predictive performance of existing regression-based models, with good generalisability and ability to rule in asthma and predict persistent wheeze.

Cellular and molecular mechanisms of allergic asthma

Asthma is a chronic disease of the airways, which affects more than 350 million people worldwide. It is the most common chronic disease in children, affecting at least 30 million children and young adults in Europe. Asthma is a complex, partially heritable disease with a marked heterogeneity. Its development is influenced both by genetic and environmental factors. The most common, as well as the most well characterized subtype of asthma is allergic eosinophilic asthma, which is characterized by a type 2 airway inflammation. The prevalence of asthma has substantially increased in industrialized countries during the last 60 years. The mechanisms underpinning this phenomenon are incompletely understood, however increased exposure to various environmental pollutants probably plays a role. Disease inception is thought to be enabled by a disadvantageous shift in the balance between protective and harmful lifestyle and environmental factors, including exposure to protective commensal microbes versus infection with pathogens, collectively leading to airway epithelial cell damage and disrupted barrier integrity. Epithelial cell-derived cytokines are one of the main drivers of the type 2 immune response against innocuous allergens, ultimately leading to infiltration of lung tissue with type 2 T helper (T_H2) cells, type 2 innate lymphoid cells (ILC2s), M2 macrophages and eosinophils. This review outlines the mechanisms responsible for the orchestration of type 2 inflammation and summarizes the novel findings, including but not limited to dysregulated epithelial barrier integrity, alarmin release and innate lymphoid cell stimulation.

Metabolomics in asthma: A platform for discovery

Asthma, characterized by airway hyperresponsiveness, inflammation and remodeling, is a chronic airway disease with complex etiology. Severe asthma is characterized by frequent exacerbations and poor therapeutic response to conventional asthma therapy. A clear understanding of cellular and molecular mechanisms of asthma is critical for the discovery of novel targets for optimal therapeutic control of asthma. Metabolomics is emerging as a powerful tool to elucidate novel disease mechanisms in a variety of diseases. In this review, we summarize the current status of knowledge in asthma metabolomics at systemic and cellular levels. The findings demonstrate that various metabolic pathways, related to energy metabolism, macromolecular biosynthesis and redox signaling, are differentially modulated in asthma. Airway smooth muscle cell plays pivotal roles in asthma by contributing to airway hyperreactivity, inflammatory mediator release and remodeling. We posit that metabolomic profiling of airway structural cells, including airway smooth muscle cells, will shed light on molecular mechanisms of asthma and airway hyperresponsiveness and help identify novel therapeutic targets.