Management of severe asthma in children

The bioflavonoid hispidulin effectively attenuates T helper type 2-driven allergic lung inflammation in the ovalbumin-induced allergic asthma mouse model

BACKGROUND

Allergic asthma affects nearly 300 million people worldwide and causes ahigh burden of disability and death. Effective treatments rely heavily on corticosteroids, which are associated with various complications. So, the alternative treatment is of significance. Hispidulin is a bioflavonoid found in herbs that were used in traditional medicine to treat inflammatory diseases, including asthma. This study aims to investigate the efficacy of hispidulin compound in the treatment of allergic lung inflammation using the mouse model of allergic asthma.

METHODS

BALB/c mice were sensitized and challenged with chicken egg ovalbumin. Cells and cytokines from bronchoalveolar lavage (BAL) fluid were examined. Lung tissues were collected for histologic study. Mouse splenic CD4+ cells were cultured to observe the effect of hispidulin on T-helper 2 (Th2) cell differentiation in vitro.

RESULTS

Hispidulin treatment could alleviate allergic airway inflammation as evidenced by a significant reduction in the inflammatory cell count and Th2 cytokines interleukin (IL)-4, IL-5, IL-13 in BAL fluid. Histologic examination of lung tissues revealed lower inflammatory cell infiltration to the bronchi and less airway goblet cell hyperplasia in the treatment group compared to the control group. At the cellular level, hispidulin (25, 50, and 100 μM) was found to directly suppress the differentiation and proliferation of Th2 cells and to suppress the production of Th2 cytokines, such as IL-4, IL-5, and IL-13, in vitro.

CONCLUSIONS

Hispidulin treatment was shown to effectively decrease type 2 lung inflammation in an ovalbumin-induced allergic asthma mouse model by directly suppressing Th2 cell differentiation and functions.

Interactions between neutrophils and T-helper 17 cells

Neutrophils comprise the majority of immune cells in human peripheral circulation, have potent antimicrobial activities, and are clinically significant in their abundance, heterogeneity, and subcellular localization. In the past few years, the role of neutrophils as components of the innate immune response has been studied in numerous ways, and these cells are crucial in fighting infections, autoimmune diseases, and cancer. T-helper 17 (Th17) cells that produce interleukin 17 (IL-17) are critical in fighting infections and maintaining mucosal immune homeostasis, whereas they mediate several autoimmune diseases. Neutrophils affect adaptive immune responses by interacting with adaptive immune cells. In this review, we describe the physiological roles of both Th17 cells and neutrophils and their interactions and briefly describe the pathological processes in which these two cell types participate. We provide a summary of relevant drugs targeting IL-17A and their clinical trials. Here, we highlight the interactions between Th17 cells and neutrophils in diverse pathophysiological situations.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

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.

Asthma Management in Children

Asthma is a common, complex heterogeneous disease often beginning in early life and is characterized by reversible airflow obstruction. The phenotypic differences that exist in children with asthma may impact underlying comorbid conditions and pharmacologic treatment choices. Prenatal factors for increased risk of asthma could include maternal diet and the maternal microbiome. Evidence also suggests that postnatal microbial exposures and colonization contribute to the risk of allergic diseases and asthma. After confirming the diagnosis, asthma management in children centers on 3 broad areas: pharmacologic treatment, treatment of underlying comorbidities, and education of the patient and caregivers on the importance of adherence and device technique. Moreover, social determinants of health significantly impact on symptom burden and treatment response.

Local IL-10 replacement therapy was effective for steroid-insensitive asthma in mice

Subgroups of patients with severe asthma showing marked increases in sputum eosinophils and/or neutrophils are insensitive to corticosteroids. Previous reports have shown that exogenous administration of an anti-inflammatory cytokine, interleukin (IL)-10 negatively regulated both eosinophilic and neutrophilic migration into tissues. The objective of this study was to elucidate whether intratracheal IL-10 administration suppresses asthmatic responses in a steroid-insensitive model of mice. Ovalbumin (OVA)-sensitized BALB/c mice were intratracheally challenged with OVA at 500 µg/animal four times. Dexamethasone (1 mg/kg, intraperitoneal) or IL-10 (25 ng/mouse, intratracheal) was administered during the multiple challenges. The number of leukocytes, expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and IL-10 receptor in the lung, and the development of airway remodeling and hyperresponsiveness were evaluated after the fourth challenge. Consistent with our previous study, dexamethasone hardly suppressed the development of airway remodeling and hyperresponsiveness. Although intratracheal IL-10 administration did not affect the development of airway remodeling, the infiltration of eosinophils and neutrophils, and the development of airway hyperresponsiveness were significantly inhibited. Moreover, IL-10 administration significantly decreased the numbers of ICAM-1⁺ and VCAM-1⁺ pulmonary vascular endothelial cells, which express IL-10 receptor 1, even though neither production of eosinophilic nor neutrophilic cytokines in the lung was inhibited. Therefore, IL-10 can suppress eosinophil and neutrophil infiltration by inhibiting the proliferation of ICAM-1⁺ and VCAM-1⁺ pulmonary vascular endothelial cells, resulting in inhibition of airway hyperresponsiveness in steroid-insensitive asthmatic mice. IL-10 replacement therapy may be clinically useful for the treatment of steroid-insensitive asthma.

Prevention and Management of High-Burden Noncommunicable Diseases in School-Age Children: A Systematic Review

BACKGROUND AND OBJECTIVES

Noncommunicable diseases (NCDs) are chronic conditions requiring health care, education, social and community services, addressing prevention, treatment, and management. This review aimed to summarize and synthesize the available evidence on interventions from systematic reviews of high-burden NCDs and risk factors among school-aged children.

METHODS

The following databases were used for this research: Medline, Embase, The Cochrane Library, and the Campbell library. The search dates were from 2000 to 2021. We included systematic reviews that synthesized studies to evaluate intervention effectiveness in children aged 5 to 19 years globally. Two reviewers independently extracted data and assessed methodological quality of included reviews using the AMSTAR 2 tool.

RESULTS

Fifty studies were included. Asthma had the highest number of eligible reviews (n = 19). Of the reviews reporting the delivery platform, 27% (n = 16) reported outpatient settings, 13% (n = 8) home and community-based respectively, and 8% (n = 5) school-based platforms. Included reviews primarily (69%) reported high-income country data. This may limit the results' generalizability for school-aged children and adolescents in low- and middle- income countries.

CONCLUSIONS

School-aged children and adolescents affected by NCDs require access to quality care, treatment, and support to effectively manage their diseases into adulthood. Strengthening research and the capacity of countries, especially low- and middle- income countries, for early screening, risk education and management of disease are crucial for NCD prevention and control.

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.

Identification of key genes and pathways between mild-moderate and severe asthmatics via bioinformatics analysis

Severe asthma is the main reason for death and disability caused by asthma. However, effective biomarkers for severe asthma have not been identified. Here, we aimed to identify potential biomarkers in severe asthma. We identified 202 differentially expressed genes (DEGs) between severe asthma and mild-moderate asthma after integrating the results from GSE69683 and GSE27011 datasets. The enrichment analysis indicated that 202 DEGs were associated with metabolism- and immune-related processes. 10 hub genes were identified by Cytoscape and five of these genes’ AUC (area under the curve) values were greater than 0.6 in GSE69683. The AUC value reached to 0.701 when combined SEC61A1 and ALDH18A1 expression. The expression of the five hub genes was verified in an external dataset. The network analysis revealed that transcription factor (TF) WT1, ZEB1, RERE, FOSL1, and miR-20a may be involved in the development of asthma. In addition, we found cyclosporine and acetaminophen could interact with these hub genes and may be negatively associated with most of the five hub genes according to previous reports. Overall, key genes were identified between mild-moderate and severe asthmatics, which contributed to the understanding of the development of asthma.

Evaluation of Glucocorticoid Therapy in Asthma Children with Small Airway Obstruction Based on CT Features of Deep Learning

This study was aimed at exploring the treatment of asthma children with small airway obstruction in CT imaging features of deep learning and glucocorticoid. A total of 145 patients meeting the requirements in hospital were included in this study, and they were randomly assigned to receive aerosolized glucocorticoid (n = 45), aerosolized glucocorticoid combined with bronchodilator (n = 50), or oral steroids (n = 50) for 4 weeks after discharge. The lung function and fractional exhaled nitric oxide (FENO) indexes of the three groups were measured, respectively, and then the effective rates were compared to evaluate the clinical efficacy of glucocorticoids with different administration methods and combined medications in the short-term maintenance treatment after acute exacerbation of asthma. Deep learning algorithm was used for CT image segmentation. The CT image is sent to the workbench for processing on the workbench, and then the convolution operation is performed on each input pixel point during the image processing. After 4 weeks of maintenance treatment, FEF50 %, FEF75 %, and MMEF75/25 increased significantly, and FENO decreased significantly (P < 0.01). The improvement results of FEF50 %, FEF75 %, MMEF75/25, and FENO after maintenance treatment were as follows: the oral hormone group was the most effective, followed by the combined atomization inhalation group, and the hormone atomization inhalation group was the least effective. The differences among them were statistically significant (P < 0.05). The accuracy of artificial intelligence segmentation algorithm was 81%. All the hormones were more effective than local medication in the treatment of small airway function and airway inflammation. In the treatment of aerosol inhalation, the hormone combined with bronchiectasis drug was the most effective in improving small airway obstruction and reducing airway inflammation compared with single drug inhalation. Deep learning CT images are simple, noninvasive, and intuitively observe lung changes in asthma with small airway functional obstruction. Asthma with small airway functional obstruction has high clinical diagnosis and evaluation value.

Considering biomarkers in asthma disease severity

Amongst patients with asthma, reliance on the type/dose of prescribed medication and symptom control does not adequately capture those at risk of adverse outcomes, and we need biomarkers for risk and treatment stratification which are consistently accurate, readily quantifiable and reproducible. The majority of patients with severe asthma, regardless of age, have predominant type-2 (T2) inflammation mediated disease, making airway/blood eosinophils, FeNO, periostin and/or allergic sensitization potentially important biomarkers for severe disease. In both adult and pediatric asthma, there is scope to improve prediction of severe attacks by using a composite T2 biomarkers of blood eosinophils and FeNO. Technological advances in component-resolved diagnostics (CRD) microarray technologies coupled with the development of interpretation software offer a possibility to use CRD as biomarkers of asthma severity amongst sensitized asthmatics. Genetic predisposition and polygenic risk scores of relevant traits (e.g., lung function, host immune responses, biomarkers of exposure from the indoor and outdoor environment, infection and microbial dysbiosis) may also contribute to prediction algorithms. We challenge the idea that asthma can be accurately defined in an individual patient by a discrete and static "endotype" (e.g., T2-high asthma). As we traverse the new era of molecular endotyping in asthma, we need to understand how relevant mechanisms impact patient outcomes, and in parallel develop new tools and approaches to stratify therapies and define individual patient trajectories.

2021 Brazilian Thoracic Association recommendations for the management of severe asthma

Advances in the understanding that severe asthma is a complex and heterogeneous disease and in the knowledge of the pathophysiology of asthma, with the identification of different phenotypes and endotypes, have allowed new approaches for the diagnosis and characterization of the disease and have resulted in relevant changes in pharmacological management. In this context, the definition of severe asthma has been established, being differentiated from difficult-to-control asthma. These recommendations address this topic and review advances in phenotyping, use of biomarkers, and new treatments for severe asthma. Emphasis is given to topics regarding personalized management of the patient and selection of biologicals, as well as the importance of evaluating the response to treatment. These recommendations apply to adults and children with severe asthma and are targeted at physicians involved in asthma treatment. A panel of 17 Brazilian pulmonologists was invited to review recent evidence on the diagnosis and management of severe asthma, adapting it to the Brazilian reality. Each of the experts was responsible for reviewing a topic or question relevant to the topic. In a second phase, four experts discussed and structured the texts produced, and, in the last phase, all experts reviewed and approved the present manuscript and its recommendations.

Reduced pediatric urgent asthma utilization and exacerbations during the COVID-19 pandemic

The COVID-19 pandemic has had a profound impact on healthcare access and utilization, which could have important implications for children with chronic diseases, including asthma. We sought to evaluate changes in healthcare utilization and outcomes in children with asthma during the COVID-19 pandemic. We used electronic health records data to evaluate healthcare use and asthma outcomes in 3959 children and adolescents, 5-17 years of age, with a prior diagnosis of asthma who had a history of well-child visits and encounters within the healthcare system. We assessed all-cause healthcare encounters and asthma exacerbations in the 12-months preceding the start of the COVID-19 pandemic (March 1, 2019-February 29, 2020) and the first 12 months of the pandemic (March 1, 2020-February 28, 2021). All-cause healthcare encounters decreased significantly during the pandemic compared to the preceding year, including well-child visits (48.1% during the pandemic vs. 66.6% in the prior year; p < .01), emergency department visits (9.7% vs. 21.0%; p < .01), and inpatient admissions (1.6% vs. 2.5%; p < .01), though there was over a 100-fold increase in telehealth encounters. Asthma exacerbations that required treatment with systemic steroids also decreased (127 vs. 504 exacerbations; p < .01). Race/ethnicity was not associated with changes in healthcare utilization or asthma outcomes. The COVID-19 pandemic corresponded to dramatic shifts in healthcare utilization, including increased telehealth use and improved outcomes among children with asthma. Social distancing measures may have also reduced asthma trigger exposure.

Prevention and Outpatient Treatment of Asthma Exacerbations in Children

Acute exacerbations cause significant morbidity and mortality in children with asthma worldwide. Although exacerbations can be minor and transient, in some children they are recurrent and significantly adversely impact quality of life. Children with frequent exacerbations account for a disproportionate amount of unscheduled care in nonprimary health facilities. Frequent exacerbators are often prescribed controller medications, but poor adherence is common. Major predictors for asthma exacerbations include genetic, social, comorbid, biological, and environmental factors. Although virus infections are a key trigger for exacerbations, other environmental factors also significantly increase risk. A previous exacerbation is a major risk factor for future exacerbations and thus identifies children to target for prevention of future episodes. In this review, we discuss both modifiable and fixed factors associated with asthma exacerbations, how to assess children for risk, and which pharmacological and nonpharmacological interventions may be of benefit. Finally, we review the current evidence around treatment within the outpatient setting for an emerging exacerbation.

Exacerbation-Prone Asthma: A Biological Phenotype or a Social Construct

Asthma is a complex syndrome with multiple phenotypes and endotypes. Asthma exacerbations are not only the clearest indictor of the morbidity of asthma and of the risk for mortality due to asthma, but also comprise a significant amount of the cost to care for poorly controlled asthma. There continues to be significant disparity in the prevalence, mortality, and morbidity due to asthma. Patients with asthma who suffer recurrent exacerbations are considered to have exacerbation-prone asthma (EPA). Efforts to characterize patients with frequent exacerbations show that the etiology is likely multifactorial. Research to determine the intrinsic risk factors for EPA include studies of both genetic and inflammatory biomarkers. External factors contributing to exacerbations have been extensively reviewed and include viral infection, environmental exposures, air pollution, and psychosocial and economic barriers to optimizing health. It is likely that EPA occurs when patients who have an increased underlying intrinsic/biological risk are placed in a given exposome (environments with a variety of exposures and triggers including allergens, pollution, stress, barriers, and occupational exposures). It is the social construct combined with underlying biology that frequently drives an EPA phenotype.

Precision Medicine for Paediatric Severe Asthma: Current Status and Future Direction

Asthma is a heterogeneous disease, characterised by different phenotypes and endotypes. Precision medicine in asthma refers to the implementation of a targeted therapy for each individual child, based on the identification of treatable traits, including environmental, immunological and genetic factors. Severe asthma in children is associated with increased hospitalisation rates, a lower quality of life, increased healthcare costs and an increased mortality. In the era of new molecular biologics treatments, it is essential to improve deep phenotyping of children with severe asthma in order to deliver the most effective treatment to each individual child. In this review, we discuss the personalised approach to the assessment and management of severe asthma. We explore the indications and use of the currently licensed biologics, as well as the potential of other emerging treatments.

Severe asthma in South Africa: A literature review and management approach for primary care

Severe asthma in South Africa (SA) is underappreciated, especially in the primary care setting. This study highlights the epidemiological context of severe asthma as a phenotypic variant. Primary care practitioners, as first-contact medical providers, need grounding in the management of severe asthma based on the precision of diagnosis and negotiated along the 10-point strategy. The underdiagnosis and undertreatment of asthma ought to inform educational programmes and research in this country.

Asthma control and psychological health in pediatric severe asthma

OBJECTIVES

Psychological comorbidities have been associated with asthma in adults and children, but have not been studied in a population of children with severe asthma. The aim of this study was to test the hypothesis that symptoms of anxiety or depression are highly prevalent in pediatric severe asthma and negatively effects asthma control.

METHODS

Longitudinal assessments of anxiety or depression symptoms (Patient Health Questionnaire-4 [PHQ-4]), asthma control (Asthma Control Test [ACT]), and lung function were performed in a single-center pediatric severe asthma clinic. Participant data were collected during routine clinical care. Primary outcomes were ACT and forced expiratory volume in 1 s per forced vital capacity (FEV1/FVC).

RESULTS

Among 43 subjects (with total 93 observations), 58.1% reported at least one anxious or depressive symptom and 18.6% had a PHQ-4 more than 2, the threshold for an abnormal test result. After adjusting for age, sex, race, and asthma medication step, there was a significant reduction in ACT for girls with PHQ-4 more than 2 (adjusted mean [SE] ACT for PHQ-4 > 2: 13.64 [0.59], ACT for PHQ-4 ≤ 2: 20.64 [1.25], p = .02) but not boys. Moreover, there was a significant differential effect of mental health impairment for girls than boys. ACT for girls with PHQ more than 2: 13.64 (0.59) compared with boys with PHQ-4 more than 2: 17.82 (0.95), adjusted mean difference ACT by sex = 4.18 points; 95% confidence interval, 0.63-7.73; p = .033. In adjusted models, there was no association between PHQ-4 more than 2 and FEV1/FVC.

CONCLUSIONS

Symptoms of anxiety and depression are common. In children with severe asthma, a PHQ-4 score more than 2 is associated with worse asthma symptom control in girls, but not boys.

Difficult and Severe Asthma in Children

Asthma is the most frequent chronic inflammatory disease of the lower airways affecting children, and it can still be considered a challenge for pediatricians. Although most asthmatic patients are symptom-free with standard treatments, a small percentage of them suffer from uncontrolled persistent asthma. In these children, a multidisciplinary systematic assessment, including comorbidities, treatment-related issues, environmental exposures, and psychosocial factors is needed. The identification of modifiable factors is important to differentiate children with difficult asthma from those with true severe therapy-resistant asthma. Early intervention on modifiable factors for children with difficult asthma allows for better control of asthma without the need for invasive investigation and further escalation of treatment. Otherwise, addressing a correct diagnosis of true severe therapy-resistant asthma avoids diagnostic and therapeutic delays, allowing patients to benefit from using new and advanced biological therapies.

Advances in understanding and reducing the burden of severe asthma in children

Severe asthma in children is rare, accounting for only a small proportion of childhood asthma. After addressing modifiable factors such as adherence to treatment, comorbidities, and adverse exposures, children whose disease is not well controlled on high doses of medication form a heterogeneous group of severe asthma phenotypes. Over the past decade, considerable advances have been made in understanding the pathophysiology of severe therapy-resistant asthma in children. However, asthma attacks and hospital admissions are frequent and mortality is still unacceptably high. Strategies to modify the natural history of asthma, prevent severe exacerbations, and prevent lung function decline are needed. Mechanistic studies have led to the development of several biologics targeting type 2 inflammation. This growing pipeline has the potential to reduce the burden of severe asthma; however, detailed assessment and characterisation of each child with seemingly severe asthma is necessary so that the most effective and appropriate management strategy can be implemented. Risk stratification, remote monitoring, and the integration of multiple data sources could help to tailor management for the individual child with severe asthma.

Need for global core competencies in Child Health and the Environment: a Canadian perspective

Children are the planet's most valuable resource. Mortality rates and longevity in children are improving; however, morbidity related to early-life exposures is increasing and with it health spending. A focus on identifying and addressing environmental components related to not only chronic childhood illnesses but also major adult mortalities would help contain current healthcare budgets. Child Health and the Environment (CHE) is an emerging discipline dedicated to managing early-life exposures (prenatal and childhood) on health outcomes throughout life. In Canada, as well as around the world, recognition of this area is growing, but progress has been slow and training of physicians is lacking. The WHO works closely with the Children's Environmental Health Clinic in Canada as well as collaborating centres around the world to build awareness of environmental health issues and promote improved care of children. Core competencies in CHE for physicians would provide an important step forward.

Kids, Difficult Asthma and Fungus

Fungi have many potential roles in paediatric asthma, predominantly by being a source of allergens (severe asthma with fungal sensitization, SAFS), and also directly damaging the epithelial barrier and underlying tissue by releasing proteolytic enzymes (fungal bronchitis). The umbrella term ‘fungal asthma’ is proposed for these manifestations. Allergic bronchopulmonary aspergillosis (ABPA) is not a feature of childhood asthma, for unclear reasons. Diagnostic criteria for SAFS are based on sensitivity to fungal allergen(s) demonstrated either by skin prick test or specific IgE. In children, there are no exclusion criteria on total IgE levels or IgG precipitins because of the rarity of ABPA. Diagnostic criteria for fungal bronchitis are much less well established. Data in adults and children suggest SAFS is associated with worse asthma control and greater susceptibility to asthma attacks than non-sensitized patients. The data on whether anti-fungal therapy is beneficial are conflicting. The pathophysiology of SAFS is unclear, but the epithelial alarmin interleukin-33 is implicated. However, whether individual fungi have different pathobiologies is unclear. There are many unanswered questions needing further research, including how fungi interact with other allergens, bacteria, and viruses, and what optimal therapy should be, including whether anti-neutrophilic strategies, such as macrolides, should be used. Considerable further research is needed to unravel the complex roles of different fungi in severe asthma.

Which Child with Asthma is a Candidate for Biological Therapies?

In asthmatic adults, monoclonals directed against Type 2 airway inflammation have led to major improvements in quality of life, reductions in asthma attacks and less need for oral corticosteroids. The paediatric evidence base has lagged behind. All monoclonals currently available for children are anti-eosinophilic, directed against the T helper (TH2) pathway. However, in children and in low and middle income settings, eosinophils may have important beneficial immunological actions. Furthermore, there is evidence that paediatric severe asthma may not be TH2 driven, phenotypes may be less stable than in adults, and adult biomarkers may be less useful. Children being evaluated for biologicals should undergo a protocolised assessment, because most paediatric asthma can be controlled with low dose inhaled corticosteroid if taken properly and regularly. For those with severe therapy resistant asthma, and refractory asthma which cannot be addressed, the two options if they have TH2 inflammation are omalizumab and mepolizumab. There is good evidence of efficacy for omalizumab, particularly in those with multiple asthma attacks, but only paediatric safety, not efficacy, data for mepolizumab. There is an urgent need for efficacy data in children, as well as data on biomarkers to guide therapy, if the right children are to be treated with these powerful new therapies.

Lung clearance index and steroid response in pediatric severe asthma

INTRODUCTION

Lung clearance index (LCI) is a measure of airway disease that has been shown to be abnormal in asthma. We hypothesized that LCI would be higher (worse) in children with severe therapy-resistant asthma (STRA) compared with difficult asthma (DA) and healthy controls and that LCI would fall in response to parenteral steroids in STRA.

METHODS

Sixty-four children with asthma who were prescribed high-dose asthma therapy (GINA steps 4 or 5) performed LCI and spirometry. Forty-three had STRA and 21 DA. Thirty-nine of forty-three STRA patients attended for a clinically indicated bronchoscopy during which an intramuscular injection of triamcinolone was given. LCI, spirometry, and fractional exhaled nitric oxide (FeNO) were performed on the day of the bronchoscopy and repeated 4 weeks later.

RESULTS

LCI was more abnormal in STRA (median: 7.40, range: 5.58-12.34) than in DA (6.55, 5.77-7.75), P = .0006, and healthy controls (6.53, 5.57-7.35), P = .005. In contrast to the first second forced expired volume (FEV₁ ), LCI improved following systemic steroids; of 20 STRA patients with an abnormal LCI at baseline, 13 improved following triamcinolone. LCI and FeNO responses were concordant.

CONCLUSIONS

There is a subgroup of children with STRA in whom LCI is elevated who improve following parenteral steroids. LCI may be a valuable additional domain in assessing steroid response in pediatric asthma.

Pharmacological interventions for the treatment of psychological distress in patients with asthma: a systematic review and meta-analysis

Objective: To evaluate the effectiveness and safety of pharmacological interventions for the treatment of psychological distress in people with asthma.Data sources: Electronic searches were performed in Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed/Medline, Embase, PsycInfo, Health Technology Assessment Database and Web of Science (inception to April 2019).Study selections: Included studies were randomized controlled trials (RCT) or controlled clinical trials investigating the effect of pharmacological interventions for psychological distress in people with asthma. Records were screened and data extracted by two independent authors into standardized pilot-tested extraction templates. Data was analyzed according to standard Cochrane methodology and entered into Review Manager Software version 5.3.Results: From 5,689 studies, six RCTs (n = 215) met inclusion criteria and were included in the systematic review, of which four studies were included in the meta-analysis. A meta-analysis of four studies (n = 158) indicated no evidence of an effect for selective serotonin reuptake inhibitors (Citalopram or Escitalopram) on reduction of psychological distress in adult patients with asthma. Similarly, antiepileptic medication (Levetiracetam) was no better than placebo in the treatment of psychological distress in people with asthma. Adverse events were poorly reported across all studies but were slightly increased among intervention participants compared to control participants.Conclusions: There was great heterogeneity between studies and overall poor methodological quality providing insufficient evidence to make recommendations for or against the use of pharmacotherapy in asthma patients with psychological distress. Further confirmatory trials are warranted to make recommendations for clinical practice.

Severe uncontrolled asthma in children: practical approach on diagnosis and management

Severe uncontrolled asthma in children is a complex and heterogeneous disease and is considered a challenge for the pediatricians. Although nearly 5% of children with asthma present with a severe uncontrolled disease, these patients and their caregivers face a significant burden, including troublesome persistent symptoms, life-threatening acute attacks, medication side effects, impaired school performance, neuropsychological problems, and lower quality of life (QoL). Moreover, these patients also account for substantially higher healthcare resource use and costs than average patients with asthma. Thus, it is essential to accurately define and diagnose severe asthma in children as they potentially need close monitoring and additional treatment with advanced therapies. This review aims to update knowledge on diagnosis and management of severe uncontrolled asthma in childhood. We describe a practical approach to differentiate children with difficult-to-treat asthma from those with true severe therapy-resistant asthma. Moreover, the recent advances in the understanding of the pathogenetic mechanisms and inflammatory mediators involved in asthma have paved the way for the development of a precision medicine approach. In this context, we analyze approved personalized therapies for severe uncontrolled asthma, focusing on the pediatric indications.

Leukotriene A4 Hydrolase Activation and Leukotriene B4 Production by Eosinophils in Severe Asthma

Asthma is associated with the overproduction of leukotrienes (LTs), including LTB4. Patients with severe asthma can be highly responsive to 5-lipoxygenase (5-LO) inhibition, which blocks production of both the cysteinyl LTs and LTB4. Production of LTB4 has traditionally been ascribed to neutrophils, mononuclear phagocytes, and epithelial cells, and acts as a chemoattractant for inflammatory cells associated with asthma. The source of LTB4 is unclear, especially in eosinophilic asthma. We speculated that the benefit of 5-LO inhibition could be mediated in part by inhibition of eosinophil-derived LTB4. LTB4 concentrations were assayed in BAL fluid from patients with severe asthma characterized by isolated neutrophilic, eosinophilic, and paucigranulocytic inflammation. Expression of LTA4 hydrolase (LTA4H) by airway eosinophils was determined by immunohistochemistry (IHC). Subsequently, peripheral blood eosinophils were activated and secreted LTB4 was quantified by enzyme immunoassay. Blood eosinophil LTA4H expression was determined by flow cytometry, qPCR, and IHC. LTB4 concentrations were elevated in BAL fluid from patients with severe asthma, including those with isolated eosinophilic inflammation, and these eosinophils displayed LTA4H via IHC. LTA4H expression by blood eosinophils was confirmed by flow cytometry, IHC, and qPCR. Robust LTB4 production by blood eosinophils was observed in response to some, but not all, stimuli. We demonstrated that eosinophils express LTA4H transcripts and protein, and can be stimulated to secrete LTB4. We speculate that in many patients with asthma, eosinophil-derived LTB4 is increased, and this may contribute to the efficacy of 5-LO inhibition.

Cytokine Responses to Rhinovirus and Development of Asthma, Allergic Sensitization, and Respiratory Infections during Childhood

RATIONALE

Immunophenotypes of antiviral responses, and their relationship with asthma, allergy, and lower respiratory tract infections, are poorly understood.

OBJECTIVES

We characterized multiple cytokine responses of peripheral blood mononuclear cells to rhinovirus stimulation, and their relationship with clinical outcomes.

METHODS

In a population-based birth cohort, we measured 28 cytokines after stimulation with rhinovirus-16 in 307 children aged 11 years. We used machine learning to identify patterns of cytokine responses, and related these patterns to clinical outcomes, using longitudinal models. We also ascertained phytohemagglutinin-induced T-helper cell type 2 (Th2)-cytokine responses (PHA-Th2).

MEASUREMENTS AND MAIN RESULTS

We identified six clusters of children based on their rhinovirus-16 responses, which were differentiated by the expression of four cytokine/chemokine groups: interferon-related (IFN), proinflammatory (Inflam), Th2-chemokine (Th2-chem), and regulatory (Reg). Clusters differed in their clinical characteristics. Children with an IFN^modInflam^highestTh2-chem^highestReg^highest rhinovirus-16-induced pattern had a PHA-Th2^low response, and a very low asthma risk (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.01-0.81; P = 0.03). Two clusters had a high risk of asthma and allergic sensitization, but with different trajectories from infancy to adolescence. The IFN^lowestInflam^highTh2-chem^lowReg^mod cluster exhibited a PHA-Th2^lowest response and was associated with early-onset asthma and sensitization, and the highest risk of asthma exacerbations (OR, 1.37; 95% CI, 1.07-1.76; P = 0.014) and lower respiratory tract infection hospitalizations (OR, 2.40; 95% CI, 1.26-4.58; P = 0.008) throughout childhood. In contrast, the IFN^highestInflam^modTh2-chem^modReg^high cluster with a rhinovirus-16-cytokine pattern was characterized by a PHA-Th2^highest response, and a low prevalence of asthma/sensitization in infancy that increased sharply to become the highest among all clusters by adolescence (but with a low risk of asthma exacerbations).

CONCLUSIONS

Early-onset troublesome asthma with early-life sensitization, later-onset milder allergic asthma, and disease protection are each associated with different patterns of rhinovirus-induced immune responses.

Pulmonary type-2 innate lymphoid cells in paediatric severe asthma: phenotype and response to steroids

Children with severe therapy-resistant asthma (STRA) have poor control despite maximal treatment, while those with difficult asthma (DA) have poor control from failure to implement basic management, including adherence to therapy. Although recognised as clinically distinct, the airway molecular phenotype, including the role of innate lymphoid cells (ILCs) and their response to steroids in DA and STRA is unknown.Immunophenotyping of sputum and blood ILCs and T-cells from STRA, DA and non-asthmatic controls was undertaken. Leukocytes were analysed longitudinally pre- and post-intramuscular triamcinolone in children with STRA. Cultured ILCs were evaluated to assess steroid responsiveness in vitroAirway eosinophils, type 2 T-helper (Th2) cells and ILC2s were significantly higher in STRA patients compared to DA and disease controls, while IL-17+ lymphoid cells were similar. ILC2s and Th2 cells were significantly reduced in vivo following intramuscular triamcinolone and in vitro with steroids. Furthermore, asthma attacks and symptoms reduced after systemic steroids despite persistence of steroid-resistant IL-17+ cells and eosinophils.Paediatric STRA and DA have distinct airway molecular phenotypes with STRA characterised by elevated type-2 cells. Systemic corticosteroids, but not maintenance inhaled steroids resulted in improved symptom control and exacerbations concomitant with a reduction in functional ILC2s despite persistently elevated IL-17+ lymphoid cells.

Asthma in Children and Adults-What Are the Differences and What Can They Tell us About Asthma?

Asthma varies considerably across the life course. Childhood asthma is known for its overall high prevalence with a male predominance prior to puberty, common remission, and rare mortality. Adult asthma is known for its female predominance, uncommon remission, and unusual mortality. Both childhood and adult asthma have variable presentations, which are described herein. Childhood asthma severity is associated with duration of asthma symptoms, medication use, lung function, low socioeconomic status, racial/ethnic minorities, and a neutrophilic phenotype. Adult asthma severity is associated with increased IgE, elevated FeNO, eosinophilia, obesity, smoking, and low socioeconomic status. Adult onset disease is associated with more respiratory symptoms and asthma medication use despite higher prebronchodilator FEV1/FVC. There is less quiescent disease in adult onset asthma and it appears to be less stable than childhood-onset disease with more relapses and less remissions.

Mouse Models for Food Allergies: Where Do We Stand?

Food allergies are a steadily increasing health and economic problem. Immunologically, food allergic reactions are caused by pathological, allergen-specific Th2 responses resulting in IgE-mediated mast cell degranulation and associated inflammatory reactions. Clinically, food allergies are characterized by local inflammation of the mouth mucosa, the face, the throat, the gastrointestinal tract, are frequently paralleled by skin reactions, and can result in life-threatening anaphylactic reactions. To better understand food allergies and establish novel treatment options, mouse models are indispensable. This review discusses the available mouse food allergy models, dividing them into four categories: (1) adjuvant-free mouse models, (2) mouse models relying on adjuvants to establish allergen-specific Th2 responses, (3) mouse models using genetically-modified mouse strains to allow for easier sensitization, and (4) humanized mouse models in which different immunodeficient mouse strains are reconstituted with human immune or stem cells to investigate humanized immune responses. While most of the available mouse models can reproducibly portray the immunological parameters of food allergy (Th2 immune responses, IgE production and mast cell activation/expansion), so far, the recreation of the clinical parameters has proven more difficult. Therefore, up to now none of the available mouse models can reproduce the complete human pathology.

Severe asthma in children-a review of definitions, epidemiology, and treatment options in 2019

Severe asthma is a relatively uncommon condition in children but one which causes morbidity, occasionally mortality, and is a challenging condition to manage. There are several definitions of severe asthma, which have a common theme of poor control despite high dose inhaled corticosteroid treatment. Depending on the definition chosen, the prevalence of severe childhood asthma may be up to 5% within populations with asthma. Collectively, there is some evidence that the treatments used in severe asthma are beneficial, but a solid evidence-base is lacking for many treatments and some treatments have recognized side effects. Evidence supporting the use of maintenance oral prednisolone and intramuscular triamcinolone is weak. Response to systemic corticosteroids is heterogeneous and recognizing phenotypes or endotypes may identify those most likely to gain maximal benefit from treatment. For children aged 6 to 11 years, the anti-IgE biologic omalizumab is effective and anti-IL-5 agent (mepolizumab) has recently been licenced in Europe (but not the US). Biologics, which are licenced for >11 year olds include omalizumab, mepolizumab, benralizumab, reslizumab, and dupilumab. There is plenty that the clinician can offer to the child and adolescent with severe asthma in 2019, including nontherapeutic and therapeutic interventions. To manage severe asthma, practitioners from broad specialities must establish and maintain a close therapeutic relationship with patients. Looking beyond 2019, more treatment options will emerge for severe childhood asthma, and clinical teams will need to continue weighing up benefits and harms.

Corticosteroids and methotrexate as adjuvants to costimulation blockade in non-human primate renal transplantation

Belatacept, the CD28-B7 costimulation pathway inhibitor, has been approved as a calcineurin inhibitor (CNI) alternative in kidney transplantation. Although costimulation blockade (CoB) allows for CNI avoidance, it is associated with increased rates of early rejection, prompting a search for agents to pair with belatacept. Methotrexate (MTX) is an antimetabolite that has been found to be complimentary with abatacept, a lower affinity CD28-B7-specific analogue of belatacept, in the treatment of rheumatoid arthritis (RA). We examined whether this synergy would extend to prevention of kidney allograft rejection. Rhesus macaques underwent kidney transplantation treated with abatacept maintenance therapy with either a steroid taper, MTX, or both. The combination of abatacept maintenance with steroids prolonged graft survival compared to untreated historical controls and previous reports of abatacept monotherapy. The addition of MTX did not provide additional benefit. These data demonstrate that abatacept with adjuvant therapy may delay the onset of acute rejection, but fail to show synergy between abatacept and MTX beyond that of steroids. These findings indicate that MTX is unlikely to be a suitable adjuvant to CoB in kidney transplantation, but also suggest that with further modification, a CoB regimen used for advanced RA may suffice for RA patients requiring kidney transplantation.

A Practical Approach to Severe Asthma in Children

Severe asthma accounts for only a small proportion of the children with asthma but a disproportionately high amount of resource utilization and morbidity. It is a heterogeneous entity and requires a step-wise, evidence-based approach to evaluation and management by pediatric subspecialists. The first step is to confirm the diagnosis by eliciting confirmatory history and objective evidence of asthma and excluding possible masquerading diagnoses. The next step is to differentiate difficult-to-treat asthma, asthma that can be controlled with appropriate management, from asthma that requires the highest level of therapy to maintain control or remains uncontrolled despite management optimization. Evaluation of difficult-to-treat asthma includes an assessment of medication delivery, the home environment, and, if possible, the school and other frequented locations, the psychosocial situation, and comorbid conditions. Once identified, aggressive management of issues related to poor adherence and drug delivery, remediation of environmental triggers, and treatment of comorbid conditions is necessary to characterize the degree of control that can be achieved with standard therapies. For the small proportion of patients whose disease remains poorly controlled with these interventions, the clinician may assess steroid responsiveness and determine the inflammatory pattern and eligibility for biologic therapies. Management of severe asthma refractory to traditional therapies involves considering the various biologic and other newly approved treatments as well as emerging therapies based on the individual patient characteristics.

Expression of corticosteroid-regulated genes by PBMCs in children with asthma

BACKGROUND

Variability in response to inhaled corticosteroids (ICSs) can result in less than optimal asthma control. Development of biomarkers assessing the therapeutic efficacy of corticosteroids is important.

OBJECTIVE

We sought to examine whether in vitro PBMC responses to corticosteroids relate to the clinical ICS response.

METHODS

PBMCs were collected from 125 children with asthma (6-17 years) at enrollment (visit 0 [V0]) and after 1 year of bimonthly guidelines-based management visits (visit 6 [V6]). Difficult-to-control and easy-to-control asthma were defined as requiring daily therapy with 500 μg or more of fluticasone propionate (FLU) with or without a long-acting β-agonist versus 100 μg or less of FLU in at least 4 visits. mRNA levels of glucocorticoid receptor α and corticosteroid transactivation (FK506-binding protein 5) and transrepression markers (IL-8 and TNF-α) were measured by using RT-PCR in freshly isolated cells and in response to 10-8 mol/L FLU.

RESULTS

Compared with PBMCs from patients with easy-to-control asthma, PBMCs from those with difficult-to-control asthma had significantly lower glucocorticoid receptor α levels at V0 (P = .05). A 30% increase in IL-8 suppression by FLU (P = .04) and a trend for increased TNF-α suppression by FLU between V0 and V6 (P = .07) were observed in patients with easy-to-control asthma. In contrast, no changes between V0 and V6 in IL-8 and TNF-α suppression by FLU were observed in patients with difficult-to-control asthma. Corticosteroid-mediated transactivation (FK506-binding protein 5 induction by FLU) increased in the PBMCs of patients with difficult-to-control and easy-to-control asthma between V0 and V6 (P = .05 and P = .03, respectively).

CONCLUSIONS

PBMCs of children with difficult-to-control asthma treated with guidelines-based therapy and requiring high-dose ICSs had reduced in vitro responsiveness to corticosteroids.

Lung Lavage Granulocyte Patterns and Clinical Phenotypes in Children with Severe, Therapy-Resistant Asthma

BACKGROUND

Children with severe asthma have frequent exacerbations despite guidelines-based treatment with high-dose corticosteroids. The importance of refractory lung inflammation and infectious species as factors contributing to poorly controlled asthma in children is poorly understood.

OBJECTIVE

To identify prevalent granulocyte patterns and potential pathogens as targets for revised treatment, 126 children with severe asthma underwent clinically indicated bronchoscopy.

METHODS

Diagnostic tests included bronchoalveolar lavage (BAL) for cell count and differential, bacterial and viral studies, spirometry, and measurements of blood eosinophils, total IgE, and allergen-specific IgE. Outcomes were compared among 4 BAL granulocyte patterns.

RESULTS

Pauci-granulocytic BAL was the most prevalent granulocyte category (52%), and children with pauci-granulocytic BAL had less postbronchodilator airflow limitation, less blood eosinophilia, and less detection of BAL enterovirus compared with children with mixed granulocytic BAL. Children with isolated neutrophilia BAL were differentiated by less blood eosinophilia than those with mixed granulocytic BAL, but greater prevalence of potential bacterial pathogens compared with those with pauci-granulocytic BAL. Children with isolated eosinophilia BAL had features similar to those with mixed granulocytic BAL. Children with mixed granulocytic BAL took more maintenance prednisone, and had greater blood eosinophilia and allergen sensitization compared with those with pauci-granulocytic BAL.

CONCLUSIONS

In children with severe, therapy-resistant asthma, BAL granulocyte patterns and infectious species are associated with novel phenotypic features that can inform pathway-specific revisions in treatment. In 32% of children evaluated, BAL revealed corticosteroid-refractory eosinophilic infiltration amenable to anti-T_H2 biological therapies, and in 12%, a treatable bacterial pathogen.

Approaches to Asthma Diagnosis in Children and Adults

Although the hallmark features of asthma include reversible airflow obstruction, airway eosinophilia, and symptoms of recurrent wheeze associated with breathlessness and cough, it is a heterogeneous disease. The extent of the pathophysiological abnormalities are variable between patients. Despite this, until recently, asthma diagnosis had been made very simplistically predominantly from a clinical history and examination, and often a trial of medication such as short acting bronchodilators. The limitations of this approach have become increasingly apparent with evidence of inappropriate over diagnosis, under diagnosis and misdiagnosis. Although there is no gold standard single test to make a diagnosis of asthma, there are several objective tests that can be used to support the diagnosis including physiological measures such as obstructive spirometry associated with bronchodilator reversibility and airway hyperresponsiveness. In addition, non-invasive tests of airway inflammation such as exhaled nitric oxide or peripheral blood eosinophils are important to identify those with an allergic or eosinophilic phenotype. Diagnostic guidelines reflect the importance of using objective tests to support a diagnosis of asthma, however practical application in the clinic may not be straightforward. The focus of this review is to discuss the need to undertake objective tests in all patients to support asthma diagnosis and not just rely on clinical features. The advantages, challenges and limitations of performing tests of lung function and airway inflammation in the clinic, the difficulties related to training and interpretation of results will be explored, and the utility and relevance of diagnostic tests will be compared in adults and children.

Severe Asthma-Perspectives From Adult and Pediatric Pulmonology

Both adults and children with severe asthma represent a small proportion of the asthma population; however, they consume disproportionate resources. For both groups it is important to confirm the diagnosis of severe asthma and ensure that modifiable factors such as adherence have, as far as possible, been addressed. Most children can be controlled on inhaled corticosteroids and long term oral corticosteroid use is rare, in contrast to adults where steroid related morbidity accounts for a large proportion of the costs of severe asthma. Atopic sensitization is very common in children with severe asthma as are other atopic conditions such as allergic rhinitis and hay fever which can impact on asthma control. In adults, the role of allergic driven disease, even in those with co-existent evidence of sensitization, is unclear. There is currently an exciting pipeline of novel biologicals, particularly directed at Type 2 inflammation, which afford the possibility of improved asthma control and reduced treatment side effects for people with asthma. However, not all drugs will work for all patients and accurate phenotyping is essential. In adults the terms T2 high and T2 low asthma have been coined to describe groups of patients based on the presence/absence of eosinophilic inflammation and T-helper 2 (TH₂) cytokines. Bronchoscopic studies in children with severe asthma have demonstrated that these children are predominantly eosinophilic but the cytokine patterns do not fit the T2 high paradigm suggesting other steroid resistant pathways are driving the eosinophilic inflammation. It remains to be seen whether treatments developed for adult severe asthma will be effective in children and which biomarkers will predict response.

Epidemiology of Asthma in Children and Adults

Asthma is a globally significant non-communicable disease with major public health consequences for both children and adults, including high morbidity, and mortality in severe cases. We have summarized the evidence on asthma trends, environmental determinants, and long-term impacts while comparing these epidemiological features across childhood asthma and adult asthma. While asthma incidence and prevalence are higher in children, morbidity, and mortality are higher in adults. Childhood asthma is more common in boys while adult asthma is more common in women, and the reversal of this sex difference in prevalence occurs around puberty suggesting sex hormones may play a role in the etiology of asthma. The global epidemic of asthma that has been observed in both children and adults is still continuing, especially in low to middle income countries, although it has subsided in some developed countries. As a heterogeneous disease, distinct asthma phenotypes, and endotypes need to be adequately characterized to develop more accurate and meaningful definitions for use in research and clinical settings. This may be facilitated by new clustering techniques such as latent class analysis, and computational phenotyping methods are being developed to retrieve information from electronic health records using natural language processing (NLP) algorithms to assist in the early diagnosis of asthma. While some important environmental determinants that trigger asthma are well-established, more work is needed to define the role of environmental exposures in the development of asthma in both children and adults. There is increasing evidence that investigation into possible gene-by-environment and environment-by-environment interactions may help to better uncover the determinants of asthma. Therefore, there is an urgent need to further investigate the interrelationship between environmental and genetic determinants to identify high risk groups and key modifiable exposures. For children, asthma may impair airway development and reduce maximally attained lung function, and these lung function deficits may persist into adulthood without additional progressive loss. Adult asthma may accelerate lung function decline and increase the risk of fixed airflow obstruction, with the effect of early onset asthma being greater than late onset asthma. Therefore, in managing asthma, our focus going forward should be firmly on improving not only short-term symptoms, but also the long-term respiratory and other health outcomes.

Pathophysiological Mechanisms of Asthma

The recent Lancet commission has highlighted that "asthma" should be used to describe a clinical syndrome of wheeze, breathlessness, chest tightness, and sometimes cough. The next step is to deconstruct the airway into components of fixed and variable airflow obstruction, inflammation, infection and altered cough reflex, setting the airway disease in the context of extra-pulmonary co-morbidities and social and environmental factors. The emphasis is always on delineating treatable traits, including variable airflow obstruction caused by airway smooth muscle constriction (treated with short- and long-acting β-2 agonists), eosinophilic airway inflammation (treated with inhaled corticosteroids) and chronic bacterial infection (treated with antibiotics with benefit if it is driving the disease). It is also important not to over-treat the untreatable, such as fixed airflow obstruction. These can all be determined using simple, non-invasive tests such as spirometry before and after acute administration of a bronchodilator (reversible airflow obstruction); peripheral blood eosinophil count, induced sputum, exhaled nitric oxide (airway eosinophilia); and sputum or cough swab culture (bacterial infection). Additionally, the pathophysiology of risk domains must be considered: these are risk of an asthma attack, risk of poor airway growth, and in pre-school children, risk of progression to eosinophilic school age asthma. Phenotyping the airway will allow more precise diagnosis and targeted treatment, but it is important to move to endotypes, especially in the era of increasing numbers of biologicals. Advances in -omics technology allow delineation of pathways, which will be particularly important in TH2 low eosinophilic asthma, and also pauci-inflammatory disease. It is very important to appreciate the difficulties of cluster analysis; a patient may have eosinophilic airway disease because of a steroid resistant endotype, because of non-adherence to basic treatment, and a surge in environmental allergen burden. Sophisticated -omics approaches will be reviewed in this manuscript, but currently they are not being used in clinical practice. However, even while they are being evaluated, management of the asthmas can and should be improved by considering the pathophysiologies of the different airway diseases lumped under that umbrella term, using simple, non-invasive tests which are readily available, and treating accordingly.

Cost-effectiveness of omalizumab for the treatment of inadequately controlled severe allergic asthma in Chinese children

Objective: The addition of omalizumab to standard therapy has proven to be efficacious in children with severe allergic asthma. The goal of this study was to assess the cost-effectiveness of adding omalizumab to standard treatment for asthma in Chinese pediatric patients.Methods: A Markov model was constructed to project the health and economic outcomes in pediatric patients with severe allergic asthma. Model inputs were obtained from the literature. Cost and quality-adjusted life-years (QALYs) were measured over a five-year time horizon. One-way and probabilistic sensitivity analyses were conducted.Results: For the base-case analysis, the addition of omalizumab to standard therapy yielded an incremental cost of $49,047 for 0.232 incremental QALY, led to an incremental cost-effectiveness ratio of $211,217/QALY. Sensitivity analyses were robust for these results.Conclusions: This study found that the addition of omalizumab is not a cost-effective strategy compared with standard therapy for children with severe allergic asthma in China due to its high cost.

Hospitalizations for asthma exacerbation in Chilean children: A multicenter observational study

BACKGROUND

Asthma hospitalization rates in Chilean children have increased in the last 14 years, but little is known about the factors associated with this.

OBJECTIVE

Describe clinical characteristics of children hospitalized for asthma exacerbation.

METHODS

Observational prospective cohort study in 14 hospitals. Over a one-year period, children five years of age or older hospitalized with asthma exacerbation were eligible for inclusion. Parents completed an online questionnaire with questions on demographic information, about asthma, indoor environmental contaminant exposure, comorbidities and beliefs about disease and treatment. Disease control was assessed by the Asthma Control Test. Inhalation technique was observed using a checklist.

RESULTS

396 patients were enrolled. 168 children did not have an established diagnosis of asthma. Only 188 used at least one controller treatment at the time of hospitalization. 208 parents said they believed their child had asthma only when they had an exacerbation and 97 correctly identified inhaled corticosteroids as anti-inflammatory treatment. 342 patients used the wrong spacer and 73 correctly performed all steps of the checklist.

CONCLUSIONS

Almost half of the patients were not diagnosed with asthma at the time of hospitalization despite having a medical history suggestive of the disease. In the remaining patients with an established diagnosis of asthma potentially modifiable factors like bad adherence to treatment and poor inhalation technique were found. Implementing a nationwide asthma program including continued medical education for the correct diagnosis and follow up of these patients and asthma education for patients and caregivers is needed to reduce asthma hospitalization rates in Chilean children.

Does allergy explain why some children have severe asthma?

Asthma is a common disease in childhood with a minority of affected children having severe therapy-resistant asthma (STRA). Children with STRA can be differentiated from those with mild-moderate disease by greater allergic sensitization, increased eosinophilic airway inflammation, increased airway remodelling and reduced corticosteroid responsiveness. The aetiology of STRA in children is multifactorial but allergy seems to play a key role. Many children with asthma have coexisting allergic disease, and severe rhinitis seems to be an important driver of STRA in children. Allergies to foods, moulds, pollen and pets have also been associated with severe asthma exacerbations. Identifying allergens that are driving asthma symptoms in children with STRA may provide additional strategies for improving their disease control. Avoidance strategies may be possible. Additional monoclonal antibody therapy with Omalizumab or Mepolizumab may be helpful in children with clinically important polysensitization.