Targeted Therapy for Severe Asthma in Children and Adolescents: Current and Future Perspectives

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.

Safety of dupilumab in T2 airways conditions: focus on eosinophilia across trials and real-life evidence

INTRODUCTION

Dupilumab, a monoclonal antibody targeting the IL-4 receptor alpha subunit, effectively blocks both IL-4 and IL-13 mediated pathways. Its introduction has represented a significant advancement in the treatment of severe asthma and other Type 2 (T2) conditions, including nasal polyps, atopic dermatitis, and eosinophilic esophagitis. To date, Dupilumab has demonstrated optimal efficacy and safety profile.

AREAS COVERED

The safety profile of dupilumab has been extensively studied, especially for its effects on blood eosinophil count. Transient eosinophil increase during treatment is typically insignificant from a clinical point of view and related to its mechanism of action. Rare cases of hyper-eosinophilia associated with clinical conditions like eosinophilic granulomatosis with polyangiitis (EGPA) and hypereosinophilic syndrome (HES) have been reported. Those cases are often related to the drug's steroid-sparing effect or the natural trajectory of the underlying disease rather than a direct cause-effect relationship with dupilumab.

EXPERT OPINION

The management of hyper-eosinophilia during dupilumab treatment requires comprehensive diagnostic work-up and strict follow-up monitoring for early detection of systemic disease progression in order to avoid unnecessary discontinuation of an effective treatment. This approach highlights the importance of a personalized treatment.

Developments in the Management of Severe Asthma in Children and Adolescents: Focus on Dupilumab and Tezepelumab

Severe asthma in children and adolescents exerts a substantial health, financial, and societal burden. Severe asthma is a heterogeneous condition with multiple clinical phenotypes and underlying inflammatory patterns that might be different in individual patients. Various add-on treatments have been developed to treat severe asthma, including monoclonal antibodies (biologics) targeting inflammatory mediators. Biologics that are currently approved to treat children (≥ 6 years of age) or adolescents (≥ 12 years of age) with severe asthma include: anti-immunoglobulin E (omalizumab), anti-interleukin (IL)-5 (mepolizumab), anti-IL5 receptor (benralizumab), anti-IL4/IL13 receptor (dupilumab), and antithymic stromal lymphopoietin (TSLP) (tezepelumab). However, access to these targeted treatments varies across countries and relies on few and crude indicators. There is a need for better treatment stratification to guide which children might benefit from these treatments. In this narrative review we will assess the most recent developments in the treatment of severe pediatric asthma, as well as potential biomarkers to assess treatment efficacy for this patient population.

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.

New approaches in childhood asthma treatment

PURPOSE OF REVIEW

This review aims to summarize the most recent advances in asthma management, focusing on novel approaches to pediatric asthma.

RECENT FINDINGS

In recent years, the therapeutic tools for pediatric asthma have expanded significantly for both the nonsevere and severe forms. The use of anti-inflammatory treatment, even for the mildest cases, and the withdrawal of symptomatic bronchodilation as monotherapy have been included in the most recent guidelines. Also, different biological therapies have revolutionized the therapeutical approach for severe uncontrolled asthma in children and adolescents.

SUMMARY

With the expanding landscape of novel therapeutic approaches for pediatric asthma, further evidence is needed to help clinicians choose the best option for patients, particularly those with severe asthma. The identification of novel predictive biomarkers may also help pediatricians in selecting children and adolescents for innovative therapies.

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.

Pediatric obesity and severe asthma: Targeting pathways driving inflammation

Asthma affects more than 300 million people of all ages worldwide, including about 10-15% of school-aged children, and its prevalence is increasing. Severe asthma (SA) is a particular and rare phenotype requiring treatment with high-dose inhaled corticosteroids plus a second controller and/or systemic glucocorticoid courses to achieve symptom control or remaining "uncontrolled" despite this therapy. In SA, other diagnoses have been excluded, and potential exacerbating factors have been addressed. Notably, obese asthmatics are at higher risk of developing SA. Obesity is both a major risk factor and a disease modifier of asthma in children and adults: two main "obese asthma" phenotypes have been described in childhood with high or low levels of Type 2 inflammation biomarkers, respectively, the former characterized by early onset and eosinophilic inflammation and the latter by neutrophilic inflammation and late-onset. Nevertheless, the interplay between obesity and asthma is far more complex and includes obese tissue-driven inflammatory pathways, mechanical factors, comorbidities, and poor response to corticosteroids. This review outlines the most recent findings on SA in obese children, particularly focusing on inflammatory pathways, which are becoming of pivotal importance in order to identify selective targets for specific treatments, such as biological agents.

Respiratory comorbidities in severe asthma: focus on the pediatric age

INTRODUCTION

Asthma comorbidities are a frequent cause of adverse outcomes, such as poor asthma control, frequent asthma attacks, reduced quality of life, and higher healthcare costs. Comorbidities are well-known treatable traits whose proper management can help achieve optimal asthma control. Although multimorbidity is frequent among asthmatics, comorbidities are still a potential cause of misdiagnosis and under or over treatments, and little is known about their impact on severe pediatric asthma.

AREAS COVERED

We provided a comprehensive, 5-year updated review focusing on the main respiratory comorbidities in severe asthma, particularly in epidemiology, pathogenesis, and current and future therapies.

EXPERT OPINION

Respiratory comorbidities have unique characteristics in childhood. Their management must be multidisciplinary, age-specific, and integrated. Further longitudinal studies are needed to understand better the mutual interrelation and synergistic effect between asthma and its respiratory comorbidities, the identification of common, treatable risk factors leading to potential asthma prevention, the effectiveness of actual and future target-therapies, and the correlation between long-lasting respiratory comorbidities and poor lung function trajectories.

A bibliometric and scientific knowledge map study of the drug therapies for asthma-related study from 1982 to 2021

Objective: Asthma drug research has been increasing yearly, and its clinical application value has increasingly attracted attention. This study aimed to analyze the development status, research hotspots, research frontiers, and future development trends of the research works on drugs for patients with asthma, especially severe asthma.

Methods: Asthma drug-related articles published between 1982 and 2021 were retrieved from the Web of Science Core Collection (WOSCC) database, and only articles published in English were included. CiteSpace and VOSviewer software were utilized to conduct collaborative network analysis of countries/regions, institutions, keywords, and co-citation analysis of references.

Results: A total of 3,234 asthma drug-related eligible articles were included. The United States was in a leading position, and Karolinska Institute (Sweden) was the most active institution. The most prolific journal in this field was Journal of Asthma, and the most cited journal was Journal of Allergy and Clinical Immunology. Keyword co-occurrence studies suggested that the current hotspots and frontiers were as follows: ① asthma: fully revealing the potential of existing conventional asthma drugs, determining the best drug delivery system, and indicating the best combination. To continue to explore potential targets for severe asthma or other phenotypes. Inhaled glucocorticoids and budesonide are still one of the important aspects of current asthma drug research and ② severe asthma: the research and development of new drugs, especially monoclonal antibodies including omalizumab, mepolizumab, and benralizumab to improve asthma control and drug safety, have become a research hotspot in recent years, highlighting the importance of “target” selection.

Conclusion: This study demonstrates the global research hotspots and trends of the research works on drugs for patients with asthma/severe asthma. It can help scholars quickly understand the current status and hotspots of research in this field.

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.

Versatile Application of Nanobodies for Food Allergen Detection and Allergy Immunotherapy

The unique characteristics of camelid heavy-chain only antibody (HCAb) derived nanobodies (Nbs) have facilitated their employment as tools for research and application in extensive fields including food safety inspection, diagnosis and therapy of diseases, etc., to develop immune detecting techniques or alternative candidates of conventional antibodies as diagnostic and therapeutic reagents. The wide application in the fields of food allergen inspection and immunotherapy has not been addressed as not much results published in the literature. The robust properties and straightforward selecting strategy of Nbs impel the advantageous employment compared with monoclonal antibodies (mAbs) to establish immunoassay and serve as blocking antibodies to compete immunoglobulin E (IgE) binding epitopes on food allergens. More and more efforts have been invested to develop specific Nbs against food allergen proteins, such as macadamia allergen of Mac i 1, peanut allergen of Ara h 3, and lupine allergen of Lup an 1, which demonstrated the potential of Nbs for research and application in food allergen surveillance. Meanwhile, the paratopes of Nbs preferably targeting the unique epitopes of food allergens can provide more possibilities to serve as blocking antibodies to shield IgE binding epitopes for food allergy immunotherapy. Regardless, the research and application of Nbs in the field of food allergen and allergic reactions are expected to attract dramatic focus and produce promising research outputs.

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.

Cystic fibrosis transmembrane conductance regulator (CFTR): beyond cystic fibrosis

Background

The cystic fibrosis transmembrane conductance regulator (CFTR) gene has been traditionally linked to cystic fibrosis (CF) inheritance in an autosomal recessive manner. Advances in molecular biology and genetics have expanded our understanding of the CFTR gene and its encoding products expressed in different tissues.

Aim

The study’s aim consists of reviewing the different pathological CF phenotypes using the existing literature. We know that alterations of the CFTR protein’s structure may result in different pathological phenotypes.

Methods

Open sources such as PubMed and Science Direct databases have been used for this review. We focused our selection on articles published within the last 15 years. Critical terms related to the CFTR protein have been used: “CFTR AND cancer,” “CFTR AND celiac disease,” “CFTR AND pancreatitis,” “children,” “adults,” “genotype,” “phenotype,” “correlation,” “mutation,”  “CFTR,” “diseases,” “disorders,” and “no cystic fibrosis.”

Results

We analyzed 1,115 abstracts in total. Moreover, only 189 were suitable for the topic. We focused on the role of CFTR in cancer, gastrointestinal disorders, respiratory diseases, reproductive system, and systemic hypertension.

Conclusions

Mutations in CFTR gene are often associated with CF. In this review, we highlighted the broad spectrum of alterations reported for this gene, which may be involved in the pathogenesis of other diseases. The importance of these new insights in the role of CFTR relies on the possibility of considering this protein/gene as a novel therapeutic target for CF- and CFTR-related diseases.

Type 2 inflammation in cystic fibrosis: New insights

Recently, type 2 inflammation has been recognized as one of the most critical factors participating in the pathogenesis of cystic fibrosis (CF). On the one hand, type 2 inflammation restores tissue homeostasis and contributes to the resolution of inflammation following an injury. On the other hand, type 2 response-activated immune cells may become dysregulated or chronically activated, causing tissue fibrosis. Among the type 2 cytokine-driven inflammatory pathways, the transforming growth factor β (TGFβ), interleukin (IL)-17, IL-33, and IL-13 have been identified as essential mediators in patients suffering from CF. Given their critical role, we firmly believe that an adequate comprehension of the type 2-mediated pathways can identify attractive targets to decrease pharmacologically the inflammation and fibrosis occurring in the pulmonary tissue of patients suffering from CF.

Management of asthma exacerbations in the paediatric population: a systematic review

Background

Asthma exacerbations in children is one of the most common medical conditions requiring urgent visits to primary healthcare providers or emergency departments, and even hospitalisations. Currently, there is significant variation in the management of asthma exacerbations expressed in guideline recommendations versus clinical practice. This disconnect affects diagnostic and treatment decisions for the clinician and patient.

Objective

We systematically reviewed the available guidelines providing recommendations for diagnostic and therapeutic management of asthma exacerbations in the paediatric population.

Methods

A systematic review of the literature for guidelines published between January 2009 and October 2019 was conducted, using a protocol registered with the international prospective register of systematic reviews (PROSPERO CRD42020221562).

Results

16 asthma exacerbation clinical practice guidelines for children were included. Despite general agreement between guidelines on the definition of asthma exacerbation, there was great variability in the definition of disease severity and assessment of asthma control. This systematic review also highlighted a paucity of recommendations for criteria for hospitalisation and discharge. Many guidelines scored poorly when measured for stakeholder involvement and editorial independence.

Conclusion

Comprehensive and updated guidelines compliant with international standards for clinical guidelines may significantly improve clinical practice quality, promote evidence-based recommendations and provide uniformity of treatment between countries.

There is wide variation in the management of asthma exacerbations in children. This systematic review suggests that updated guidelines aligned with international standards for clinical guidelines may improve uniformity of treatment and clinical practice quality.https://bit.ly/32Pgdiz

Monoclonal Antibodies in Treating Food Allergy: A New Therapeutic Horizon

Food allergy (FA) is a pathological immune response, potentially deadly, induced by exposure to an innocuous and specific food allergen. To date, there is no specific treatment for FAs; thus, dietary avoidance and symptomatic medications represent the standard treatment for managing them. Recently, several therapeutic strategies for FAs, such as sublingual and epicutaneous immunotherapy and monoclonal antibodies, have shown long-term safety and benefits in clinical practice. This review summarizes the current evidence on changes in treating FA, focusing on monoclonal antibodies, which have recently provided encouraging data as therapeutic weapons modifying the disease course.

Nocturnal non invasive ventilation in normocapnic cystic fibrosis patients: a pilot study

BACKGROUND AND AIM

In patients with cystic fibrosis (CF) non-invasive ventilation (NIV) improves lung mechanics and gas exchange, and decreases the work of breathing. Domiciliary NIV is mainly used in hypercapnic patients with severe disease, because it counteracts the progression of lung functional impairment and it is often used as a useful "bridge" to lung transplantation. However, to date, there are no standardized criteria to indicate the effect of a precocious starting of NIV in patients with functional ventilation inhomogeneity without hypercapnia. In this pilot study we assessed whether an early NIV treatment might influence functional and clinical outcomes in CF patients.

METHODS

Six normocapnic CF patients were treated for one year with NIV. At baseline and after 1 year of NIV treatment, arterial gas analysis, spirometry, MBW to derive LCI, nocturnal cardio-respiratory polygraphy (PG), and Pittsburgh Sleep Quality Index (PSQI) were perfomed in all enrolled patients.

RESULTS

After one year, despite spirometric and LCI values remain statistically not modified, the number of infectious exacerbations was reduced by 50%.

CONCLUSIONS

These results suggest that nocturnal NIV improves clinical conditions of stable CF patients. Finally, we suggest that this procedure can be useful to counteract the progression of lung disease even in normocapnic patients.

Biological Therapies in Children and Adolescents with Severe Uncontrolled Asthma: A Practical Review

Severe uncontrolled asthma is a complex and heterogeneous disease. A multidisciplinary assessment is required to correctly identify and manage children and adolescents with severe asthma because they may require strict monitoring and additional treatment with advanced targeted therapies. Recent research efforts have focused on identifying epidemiologic, clinical, and molecular mechanisms that underlie severe asthma, leading to the recognition of different phenotypes and endotypes and identifying biomarkers able to predict the response to biologic therapies. Additional progress has occurred by introducing biological therapies that have revolutionized the care of chronic allergic diseases in the adult and pediatric population. In this review, we briefly summarized the current literature on biological therapies to treat severe asthma in children and adolescents.

The Relationship Between Indicators of Nasal Respiratory Function and Spirometric Parameters in Children With Bronchial Asthma

Introduction: The relationship between objective indicators of nasal obstruction and airflow limitation in children with bronchial asthma (BA) and allergic rhinitis (AR) has not yet been studied. Objective: To study the relationship between objective parameters of nasal obstruction and airflow limitation, determined using the methods of anterior active rhinomanometry (AARM) and spirometry in children with BA and AR. Materials and Methods: Eighty eight children and adolescents with BA and AR, boys-65.9% (58/88), were examined. The median age was 11.09 [10.42; 11.76] years. To determine airflow limitation, the following spirometric parameters were evaluated: forced vital capacity of the lungs (FVC), forced expiratory volume in 1 s (FEV1), the ratio of FEV1/FVC, and maximum expiratory flow at the point 25% of the flow-volume loop (MEF25). Data were recorded both in absolute values and in relative units (% pred). Nasal respiratory function was determined by AARM based on the total nasal airflow (TNAF) in absolute (Pa/cm3/s) and relative units (RTNAF, % pred). Results: In the general cohort and in boys but not in girls, a statistically significant direct correlation was found between TNAF (Pa/cm3/s) and absolute spirometry parameters of bronchial patency-all had p < 0.01. Also, RTNAF and relative MEF25 values (% pred) in the general cohort were R = 0.22, p = 0.04, and in boys, R = 0.28, p = 0.03. In girls, there was no statistically significant correlation between nasal respiratory function and spirometric parameters, all p > 0.05. Additional analysis of literature was conducted to ascertain that the identified gender differences were not occasional. Conclusion: The significant positive correlation of absolute values of AARM and spirometric parameters in children with BA and AR was established, which apparently reflects the physical development of children. Of all the relative indicators of spirometry, only MEF25 (% pred), which indirectly reflects the patency of small bronchi, had a distinct direct correlation with RTNAF. These patterns are clearly expressed in boys with BA. In girls with this disease, however, the relationship between nasal respiratory function and spirometric indicators seems to be more complex and requires further study.

Correlations between exhaled nitric oxide, rs28364072 polymorphism of FCER2 gene, asthma control, and inhaled corticosteroid responsiveness in children with asthma

In children with asthma, the responsiveness of inhaled corticosteroids (ICS) is depended on asthma endotype and phenotype. This study aimed to describe the clinical and biological characteristics, and its correlation with polymorphism of rs28364072 in FCER2 of asthmatic children. This work aimed to study the correlation between fractional concentration of exhaled nitric oxide (FE_NO) level and rs28364072 polymorphism of FCER2 gene with ICS responsiveness and disease control in children with asthma. This study was a prospective and descriptive study. All clinical characteristics, FE_NO, blood eosinophil counts (BEC), skin prick test (SPT), total IgE, asthma control test, and FCER2 gene polymorphism were performed for each patient. One hundred and seven asthmatic children who were over 5 years old (9.2 ± 2.6), were included. Patients with FE_NO > 20 ppb had higher percentage of positive SPT, total IgE level, and BEC (89.2 vs 80.0%, 851.1 vs 656.9 UI ml^-1, and 785 ± 576 G L^-1 vs 425 ± 364 G L^-1; respectively). Among them, there were 54.2% of homozygous TT, 36.4% of heterozygous TC, and 9.4% of homozygous CC of rs28364072 polymorphism in FCER2. The percentage of patients with controlled asthma was increasing after 1 month and 3 months (47.1% and 58.8%; respectively). During the study, the ICS was decreasing as indicated by asthma control (348 ± 118 mcg at 1st month vs 329 ± 119 mcg at 3rd month; p < 0.05). CC genotype had the lowest level of increasing FEV1 compared to that in genotype TC and TT (8.4% vs 8.7% and 27.1%; p > 0.05 and p < 0.05; respectively). The percentage of polymorphism in rs28364072 of FCER2 was significant higher in patients with controlled asthma compared to uncontrolled asthma. Asthmatic children with high FE_NO and rs28364072 polymorphism in FCER2 gene are good responders to ICS; however, asthmatic children with homozygous variant CC of rs28364072 are poorly responsive to ICS.

Allergic bronchopulmonary aspergillosis in children

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disease caused by Aspergillus induced hypersensitivity that occurs in immunocompetent but susceptible patients with asthma and/or cystic fibrosis (CF). In children, ABPA remains mostly undiagnosed resulting in one of the most common causes of poorly controlled asthma and highly significant morbidity in children with CF. Currently, no specific diagnostic criteria of ABPA for children are available. Corticosteroids and itraconazole are the mainstays of therapy although there is a lack of randomized clinical trials regarding their usefulness for ABPA in children. Several monoclonal antibodies, such as omalizumab and mepolizumab, may be potential therapies for refractory ABPA in pediatric patients; however, further data are required to clarify the optimal dose and duration of therapy as a routine treatment approach.

Antihistamines in children and adolescents: A practical update

Histamine is a chemical mediator, released predominantly by tissue mast cells, circulating basophils, and neurons, which are activated in response to various immunological and non-immunological stimuli. Histamine has to bind to specific receptors to exert its physiological and pathophysiological functions. Endogenous histamine is the main mediator of the immediate allergic response, which moreover, performs other multiple functions, including regulation of gastric secretion, neurotransmission in the central nervous system, and immunomodulatory activity. The involvement of histamine in various disorders and the importance of receptors in the clinical features have relevant implications in clinical practice. Anti-H1 antihistamines contrast the histamine-dependent effects, mainly concerning nasal symptoms and cutaneous itching and wheal. Antihistamines are among the most prescribed drugs in pediatric care. This review updates the practical use of antihistamines in children and adolescents.

Anti-IL-5 in pediatric allergic diseases

Interleukin (IL)-5 is a potent mediator of the inflammatory cascade in the allergic response. Its predominant role in atopic reactions makes this cytokine an ideal target for blocking the eosinophilic inflammatory hyper-responsiveness to allergens. The management of allergic diseases in childhood-such as severe asthma, atopic dermatitis, and eosinophilic esophagitis-is a challenge. In particular, there are concerns regarding the use of high-dose corticosteroids. Over the last few years, biologics targeting IL-5 or IL-5 receptor-that are mepolizumab, reslizumab, and benralizumab-represent a new, promising, and more personalized therapeutic option.

Type-2 inflammatory mediators as targets for precision medicine in children

The prevalence, heterogeneity, and severity of type 2 inflammatory diseases, including asthma and atopic dermatitis, continue to rise, especially in children and adolescents. Type 2 inflammation is mediated by both innate and adaptive immune cells and sustained by a specific subset of cytokines, such as interleukin (IL)-4, IL-5,IL-13, and IgE. IL-4 and IL-13 are considered signature type 2 cytokines, as they both have a pivotal role in many of the pathobiologic changes featured in asthma and atopic dermatitis. Several biologics targeting IL-4, IL-5, and IL-13, as well as IgE, have been proposed to treat severe allergic disease in the pediatric population with promising results. A better definition of type 2 inflammatory pathways is essential to implement targeted therapeutic strategies.

Asthma in children and adolescents: the ControL'Asma project

The control of asthma is the objective of asthma management. However, it is difficult to obtain in clinical practice. The Italian Society of Allergy and Clinical Immunology promoted the nationwide project "ControL'Asma" to investigate the real situation in a group of children and adolescents with asthma. The preliminary outcomes demonstrated that many asthmatic subjects do not achieve adequate asthma control. Moreover, asthma in Italian children and adolescents was usually more frequent in males, had an early onset and allergic phenotype with very frequent rhinitis comorbidity, uncontrolled and partly controlled asthma affected about the half of subjects. However, this project suggested that the assessment of asthma symptom perception by VAS could be a reliable tool in the asthma management.

An update on the role of chronic rhinosinusitis with nasal polyps as a co-morbidity in severe asthma

INTRODUCTION

Chronic rhinosinusitis and asthma are heterogeneous diseases with complex pathogenesis. The presence of chronic rhinosinusitis with nasal polyps has been associated with increased asthma exacerbation frequency and may represent a predictor of future exacerbations in severe asthma.

AREAS COVERED

This review provides the clinician with an overview of the prevalence and clinical impact of the chronic rhinosinusitis with nasal polyps in severe asthma and summarizes recommended therapeutic approaches, including innovative biologic therapies. To select relevant literature for inclusion in this review, we conducted a literature search using the PubMed and ClinicalTrials.gov databases, using terms 'chronic rhinosinusitis with nasal polyps' AND 'asthma' OR 'severe asthma.' The literature review was performed for publication years 2010-2020, restricting the articles to humans and English language publications.

EXPERT OPINION

Biological therapies have opened new perspectives in the treatment of upper and lower airway allergic diseases. Care pathways in severe asthma are almost consolidated, while they still rely on phenotypic rather than endotypic features in chronic rhinosinusitis with nasal polyps. Unveiling the correlation between clinical phenotypes and molecular endotypes will allow better stratification of patients with chronic rhinosinusitis with nasal polyps to identify candidates who benefit most from biological therapy.

Pidotimod in allergic diseases

The rising incidence of allergic disease requires more specific, effective and safe therapeutic strategies. In this regard, several kinds of biologically active substances, commonly known as immunostimulants, have been introduced for the prevention and treatment of allergic diseases in pediatric population. Among the heterogeneous group of biologically active molecules to date available, pidotimod (Axil, Valeas S.p.A, Milan) is proved to be able to ameliorate both innate and adaptive immunity and enhances the immune system properties often impaired in patients with allergic disorders.

An update on biological therapies for pediatric allergic diseases

Allergic diseases represent a global health burden. Patients with allergic diseases may experience disability, reduced quality of life and productivity, emotional distress, and social restrictions, especially in the most severe cases. Current advances in unveiling the pathogenesis of allergic disorders have paved the way for the development of novel therapeutic strategies. Biological drugs have been widely studied in pediatric allergic asthma, with strong evidence of efficacy and safety. Moreover, promising results derive from studies on other conditions such as atopic dermatitis, chronic spontaneous urticaria, and food allergy. This review analyzes recent evidence on the role of biologic therapies for allergic diseases, focusing on the pediatric age.

Dupilumab to Treat Type 2 Inflammatory Diseases in Children and Adolescents

During the past decade, significant therapeutic progress has been made in the field of allergic diseases, mainly concerning the pathogenic role of type 2 inflammation. Biologics targeting specific key cytokines, such as interleukin (IL)-4, IL-5, and IL-13, as well as IgE, have emerged as promising innovative therapies for allergic disorders. In this context, dupilumab has emerged as one of the most successful therapies targeting the IL-4R axis. Dupilumab is a human IgG4 antibody anti-IL-4 receptor (IL-4R) α-subunit that blocks IL-4R signaling induced by both IL-4 and IL-13, downregulating the molecular pathways that drive type 2 inflammatory diseases, including atopic dermatitis, allergic rhinitis, allergic asthma, chronic rhinosinusitis with nasal polyps, and eosinophilic esophagitis. This review presents the most recent evidence on dupilumab for the treatment of type 2 inflammatory diseases and discusses the future perspective, focusing on the pediatric age group and adolescents.

Hypersensitivity Reactions to Monoclonal Antibodies in Children

Biologic drugs are widely used in pediatric medicine. Monoclonal antibodies (mAbs) in particular are a therapeutic option for rheumatic, autoinflammatory and oncologic diseases. Adverse drug reactions and hypersensitivity reactions (HSR) to mAbs may occur in children. Clinical presentation of HSRs to mAbs can be classified according to phenotypes in infusion-related reactions, cytokine release syndrome, both alpha type reactions and type I (IgE/non-IgE), type III, and type IV reactions, all beta-type reactions. The aim of this review is to focus on HSRs associated with the most frequent mAbs in childhood, with particular attention to beta-type reactions. When a reaction to mAbs is suspected a diagnostic work-up including in-vivo and in-vitro testing should be performed. A drug provocation test is recommended only when no alternative drugs are available. In selected patients with immediate IgE-mediated drug allergy a desensitization protocol is indicated. Despite the heavy use of mAbs in childhood, studies evaluating the reliability of diagnostic test are lacking. Although desensitization may be effective in reducing the risk of reactions in children, standardized pediatric protocols are still not available.

Measuring inflammation in paediatric severe asthma: biomarkers in clinical practice

Severe asthma in children is a highly heterogeneous disorder, encompassing different clinical characteristics (phenotypes) and immunopathological pathways (endotypes). Research is focusing on the identification of noninvasive biomarkers able to predict treatment response and assist in designing personalised therapies for severe asthma. Blood and sputum eosinophils, serum IgE and exhaled nitric oxide fraction mostly reflect type 2 airway inflammation in children. However, in the absence of available point-of-care biomarkers, the diagnosis of non-type 2 asthma is still reached by exclusion. In this review, we present the most recent evidence on biomarkers for severe asthma and discuss their implementation in clinical practice. We address the methods for guiding treatment decisions and patient identification, focusing on the paediatric age group.

Noninvasive biomarkers should be integrated with clinical findings to assist in diagnosing and guiding personalised therapies for severe asthma in childrenhttp://bit.ly/2JPvKFV

Pediatric use of omalizumab for allergic asthma

INTRODUCTION

Severe pediatric asthma is associated with significant morbidity as well as with a high economic burden. It represents a heterogeneous disease with multiple clinical phenotypes. Currently, physicians are facing the challenge to provide a 'personalized medicine approach', which is tailored to the diverse pathomechanisms underlying clinical presentations. Three main endotypes of airway inflammation have been described in children with severe asthma. While neutrophilic and paucigranulocytic inflammatory patterns are quite uncommon in childhood, type Th2 inflammation asthma with elevated IgE is the most prevalent in pediatric asthma. Considering the pivotal role of IgE in type Th2 inflammation asthma, the blockade of IgE using anti-IgE therapy represents a potent therapeutic option for severe pediatric asthma in children.

AREAS COVERED

This review aims to focus on the role of omalizumab as a treatment option in pediatric patients (aged six years and above) with severe allergic asthma.

EXPERT OPINION

The clinical efficacy and safety of omalizumab for the treatment of pediatric asthma is well documented in clinical trials and observational studies. Further studies are still required to characterize the potential benefit of anti-IgE therapy in airway remodeling, identify additional biomarkers of clinical response and address current unmet needs, including the limit on omalizumab use in children younger than six years.

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.

Current and emerging biologic therapies for allergic rhinitis and chronic rhinosinusitis

Introduction: Allergic rhinitis and chronic rhinosinusitis, with and without nasal polyps, are the most common chronic inflammatory diseases of the upper airways. They both cause relevant respiratory symptoms and a substantial detriment to patients' quality of life, mainly in uncontrolled and severe patients.Areas covered: This review aims to present the most recent evidence on current and emerging biologic therapies for allergic rhinitis and chronic rhinosinusitis and discuss their potential implementation in clinical practice. To select relevant literature for inclusion in this review, we conducted a literature search using the PubMed database, using terms 'biologics OR biological agents', 'allergic rhinitis' and 'chronic rhinosinusitis'. The literature review was performed for publication years 2009-2019, restricting the articles to humans and English language publications.Expert opinion: Biological therapies represent a potential step forward in providing individualized care for all patients with uncontrolled severe upper airway diseases. Biologics recently showed promising results for the treatment of severe uncontrolled allergic rhinitis and chronic rhinosinusitis with nasal polyps with or without associated asthma. Endotyping inflammatory pathways and identifying related biomarkers remain the major challenge for positioning biologics in the care pathway of chronic respiratory diseases.

Severe asthma in children: Current goals and unmet needs

Severe asthma in children is considered a complex and heterogeneous disease. A multidisciplinary assessment is required to correctly identify and manage these children because they potentially need close monitoring and additional treatment with advanced targeted therapies. Recent research efforts focused on the identification of epidemiologic, clinical, and functional characteristics of the disease in the pediatric age. Novel findings on the molecular mechanisms underlying severe asthma have led to the recognition of different endotypes and related biomarkers able to predict the response to advanced biologic therapies. Progress in our knowledge of severe asthma has occurred with the introduction of biologic therapies. Future goals in asthma care include the identification of the links between phenotypes and endotypes, as well as the identification of novel predictive biomarkers. They will help to select candidates for innovative biologic therapies and ultimately improve outcomes in children with severe asthma.

Omalizumab and mepolizumab in the landscape of biological therapy for severe asthma in children: how to choose?

Severe asthma has a substantial epidemiological impact on children and biological treatments can be an option to take into account, as they target specific molecules and pathways involved in its pathogenesis. Modern medicine is continuously and progressively oriented towards tailored treatments designed specifically for the pathology patterns observed in individual patients and identified as endotypes with associated biomarkers. In this regard, biologic treatments in asthma are one of the best examples. Among the biological drugs currently available, omalizumab is the one with the greatest amount of data on efficacy and safety, and the one we have more real-life clinical experience with. However, mepolizumab will likely be accessible soon globally for clinical use. Moreover, research on biological drugs for the treatment of severe asthma is expanding rapidly, with some molecules currently used in adult patients that could be registered also for pediatric use and new molecules that could be available in the future. On the other hand, due to this potential abundance of therapeutic options, new criteria could become necessary to guide clinicians through an evidence-based choice between omalizumab and these new drugs. For the same reason, more data collected specifically from pediatric clinical trials are necessary. In this review we aim to analyze the factors that could help clinicians make their choice and to highlight the unmet need for a more evidence-based choice.

The Impact of Ambient Environmental Exposures to Microbial Products on Asthma Outcomes from Birth to Childhood

Purpose of Review

Asthma is a chronic respiratory condition with increasing domestic and worldwide prevalence that burdens individuals and the healthcare system with high costs associated with long-term treatments and acute emergency room (ER) visits. It can be triggered by ambient microbes, including bacteria, viruses, and fungi. In this review, we examine the outcomes of asthma patients in relation to environmental exposures to ambient microbe products, focusing on whether exposure leads to asthma development from birth to childhood and if particular microbes are associated with worsened asthma exacerbations.

Recent Findings

Bacterial endotoxin is more prominent in homes with pets and may cause cytokine cascades that lead to asthma exacerbation. However, some studies have demonstrated a protective effect with early exposure. Patients with positive Aspergillus skin testing are more prone to moderate-severe or severe-uncontrolled asthma. Fungal sensitization is also associated with earlier onset of asthma and demonstrates a dose-dependent relationship of symptom severity and duration. Among viruses, rhinovirus has the greatest association with decreased lung function, severe asthma, and asthma-related hospital admissions. Distribution of microbial products and associated asthma symptoms depends on the geographical climate. Genetic variations among individuals also mitigate the effects of microbial products on asthma development and symptom severity.

Summary

Microbial products of bacteria, fungi, and viruses are associated with the development of asthma, more severe asthma symptoms, and worse outcomes. However, some early exposure studies have also demonstrated a protective effect. Bacterial and fungal products are related to decreased lung function and earlier onset of asthma. Viral products are related to asthma-associated hospital admissions; and the climate and patient genetics can also temper or intensify the relationships between microbial products, asthma development, and asthma symptom severity. Further research should focus on the effects of early microbe exposure and its interaction with human immune systems and asthma-related outcomes.

Update in Pediatric Asthma: Selected Issues

Asthma is a complex condition that affects 14% of the world's children and the approach to management includes both pharmacologic as well as non-pharmacologic strategies including attention to complex socioeconomic status phenomena. After an historical consideration of asthma, allergic and immunologic aspects of asthma in children and adolescents are presented. Concepts of socioeconomic aspects of asthma are considered along with environmental features and complications of asthma disparities. Also reviewed are links of asthma with mental health disorders, sleep disturbances and other comorbidities. A stepwise approach to asthma management is discussed that includes pharmacologic and non-pharmacologic strategies in the pediatric population. The role of immunotherapy and use of various immunomodulators are considered as well.