Severe childhood asthma: a common international approach?

Use of exhaled nitric oxide in the diagnosis and monitoring of childhood asthma: myth or maxim?

Asthma is a common condition in children. This review describes the evidence from the literature and international asthma guidelines for using fractional exhaled nitric oxide (FENO) in the diagnosis and monitoring of childhood asthma. The accuracy of FENO measuring devices could be further improved, the difference in FENO results between devices are equivalent to what is considered a clinically important difference. For diagnosing asthma no guideline currently recommends FENO is used as the first test, but many recommend FENO as part of a series of tests. A cut-off of 35 ppb is widely recommended as being supportive of an asthma diagnosis, but evidence from children at risk of asthma suggests that a lower threshold of 25 ppb may be more appropriate. Nine randomised clinical trials including 1885 children have added FENO to usual asthma care and find that exacerbations are reduced when care is guided by FENO (OR for exacerbation compared to usual care 0.77, 95% CI 0.62-0.94). What is not clear is what cut-off(s) of FENO should be used to trigger a change in treatment. After 30 years of intensive research there is not sufficient evidence to recommend FENO for routine diagnosing and monitoring asthma in children.

Educational aims

To give the reader an overview of literature that supports and does not support the role of FENO in diagnosing asthma in children.To give the reader an overview of literature that supports and does not support the role of FENO in monitoring asthma in children.To give the reader an understanding of the role of FENO in international guidelines for diagnosing and monitoring asthma in children.

Lung-on-chip microdevices to foster pulmonary drug discovery

Respiratory diseases account for unprecedented mortality owing to a lack of personalized or insufficient therapeutic interventions. Fostering pulmonary research into managing pulmonary threat requires a potential alternative approach that can mimick the in vivo complexities of the human body. The in vitro miniaturized bionic simulation of the lung holds great potential in the quest for a successful therapeutic intervention. This review discusses the emerging roles of lung-on-chip microfluidic simulator devices in fostering translational pulmonary drug discovery and personalized medicine. This review also explicates how the lung-on-chip model emulates the breathing patterns, elasticity, and vascularization of lungs in creating a 3D pulmonary microenvironment.

Progress in diagnosis and treatment of difficult-to-treat asthma in children

At present, medications containing inhaled corticosteroids (ICS-containing) are the keystones of asthma treatment. The majority of asthmatic children can significantly improve clinical outcomes with little worsening by standardized inhaled glucocorticoid treatment, but there is still a small proportion of children who are unable to achieve good symptom control even after the maximum standardized treatment, known as 'children with difficult-to-treat asthma (DA)'. The high heterogeneity of DA makes therapy challenging and expensive, which poses a serious risk to children's health and makes it extremely difficult for clinical physicians to accurately identify and treat children with DA. This article reviews the definition, evaluation, and treatment of this asthma in order to provide a reference for optimal clinical decision-making.

An Overview of the Obese-Asthma Phenotype in Children

Asthma is the most common chronic disease in childhood. Overweight and obesity are included among the comorbidities considered in patients with difficult-to-treat asthma, suggesting a specific phenotype of the disease. Therefore, the constant increase in obesity prevalence in children and adolescents raises concerns about the parallel increase of obesity-associated asthma. The possible correlation between obesity and asthma has been investigated over the last decade by different authors, who suggest a complex multifactorial relationship. Although the particular non-eosinophilic endotype of obesity-related asthma supports the concept that high body weight precedes asthma development, there is ongoing debate about the direct causality of these two entities. A number of mechanisms may be involved in asthma in combination with obesity disease in children, including reduced physical activity, abnormal ventilation, chronic systemic inflammation, hormonal influences, genetics and additional comorbidities, such as gastroesophageal reflux and dysfunctional breathing. The identification of the obesity-related asthma phenotype is crucial to initiate specific therapeutic management. Besides the cornerstones of asthma treatment, lifestyle should be optimized, with interventions aiming to promote physical exercise, healthy diet, and comorbidities. Future studies should clarify the exact association between asthma and obesity and the mechanisms underlying the pathogenesis of these two related conditions with the aim to define personalized therapeutic strategies for asthma management in this population.

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.

Advanced human-relevant in vitro pulmonary platforms for respiratory therapeutics

Over the past years, advanced in vitro pulmonary platforms have witnessed exciting developments that are pushing beyond traditional preclinical cell culture methods. Here, we discuss ongoing efforts in bridging the gap between in vivo and in vitro interfaces and identify some of the bioengineering challenges that lie ahead in delivering new generations of human-relevant in vitro pulmonary platforms. Notably, in vitro strategies using foremost lung-on-chips and biocompatible "soft" membranes have focused on platforms that emphasize phenotypical endpoints recapitulating key physiological and cellular functions. We review some of the most recent in vitro studies underlining seminal therapeutic screens and translational applications and open our discussion to promising avenues of pulmonary therapeutic exploration focusing on liposomes. Undeniably, there still remains a recognized trade-off between the physiological and biological complexity of these in vitro lung models and their ability to deliver assays with throughput capabilities. The upcoming years are thus anticipated to see further developments in broadening the applicability of such in vitro systems and accelerating therapeutic exploration for drug discovery and translational medicine in treating respiratory disorders.

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.

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.

An approach to the management of children with problematic severe asthma

Children with poor asthma control despite high levels of prescribed treatment are described as having problematic severe asthma. Most of these children have steroid sensitive disease which improves with adherence to daily inhaled corticosteroids and after having removed modifiable factors like poor inhalation technique, persistent adverse environmental exposures and psychosocial factors. These children are described as having “difficult-to-treat asthma” while children with persistent symptoms despite above-mentioned factors having been addressed are described as having “severe therapy-resistant asthma”. In this review, we will describe the 6-step approach to the diagnosis and management of a child with problematic severe asthma adopted by The Royal Brompton Hospital (London, UK). The role of a multidisciplinary team is crucial for identification and treatment of modifiable factors and comorbidities in order to avoid invasive examinations and useless pharmacological treatments. The current knowledge on add-on therapies will be discussed.

Fluctuation-based clustering reveals phenotypes of patients with different asthma severity

Serial peak expiratory flow (PEF) measurements can identify phenotypes in severe adult asthma, enabling more targeted treatment. The feasibility of this approach in children has not been investigated.

Overall, 105 children (67% male, median age 12.4 years) with a range of asthma severities were recruited and followed up over a median of 92 days. PEF was measured twice daily. Fluctuation-based clustering (FBC) was used to identify clusters based on PEF fluctuations. The patients’ clinical characteristics were compared between clusters.

Three PEF clusters were identified in 44 children with sufficient measurements. Cluster 1 (27% of patients: n=12) had impaired spirometry (mean forced expiratory volume in 1 s (FEV₁) 71% predicted), significantly higher exhaled nitric oxide (≥35 ppb) and uncontrolled asthma (asthma control test (ACT) score <20 of 25).

Cluster 2 (45%: n=20) had normal spirometry, the highest proportion of difficult asthma and significantly more patients on a high dose of inhaled corticosteroids (≥800 µg budesonide).

Cluster 3 (27%: n=12) had mean FEV₁ 92% predicted, the highest proportion of patients with no bronchodilator reversibility, a low ICS dose (≤400 µg budesonide), and controlled asthma (ACT scores ≥20 of 25).

Three clinically relevant paediatric asthma clusters were identified using FBC analysis on PEF measurements, which could improve telemonitoring diagnostics. The method remains robust even when 80% of measurements were removed. Further research will determine clinical applicability.

Fluctuation-based clustering is a robust method that identifies clinically relevant subgroups of patients with asthma to refine referral strategies to a tertiary centrehttps://bit.ly/35g1ldb

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.

Impact of asthma severity on long-term asthma control

Background: Asthma is a common childhood disease with significant morbidity. Severe asthma accounts for just 4-6% of patients, but this group is more difficult to treat and is responsible for up to 40% of asthma expenses.Objective: The relationship between asthma severity and control is not well characterized. The main objective of this study was to determine impact of asthma severity on asthma control over time.Methods: This was a three year, prospective observational cohort study at a tertiary care children's hospital. Results were compared over time and between patients with severe and non-severe persistent asthma. Intervention included therapy based on severity and control, accompanied by a NAEPP (EPR-3) guidelines based structured asthma education program.Results: The sample included 471 children referred from primary care offices with the diagnosis of persistent asthma, mean age 6.4 ± 2.4 years. Forty-one children (8.7%) had severe persistent asthma and 430 (91.3%) children had non-severe persistent asthma (mild-moderate persistent). Our sample size decreased over the three-year period and the number of patients completing the third year were 176 (38%) and among them 20 (11.4%) had severe asthma. At the initial visit, children with severe persistent asthma had significantly more acute care needs, more daily symptoms, and lower mean Asthma Control Test™ scores compared to children with non-severe persistent asthma. Differences between groups decreased within six months with significant improvements in most indicators persisting throughout three-year follow up in both groups (p < 0.05).Conclusion: Asthma control improves independent of severity if asthma guidelines are followed.

Lung-on-a-chip: the future of respiratory disease models and pharmacological studies

Recently, organ-on-a-chip models, which are microfluidic devices that mimic the cellular architecture and physiological environment of an organ, have been developed and extensively investigated. The chips can be tailored to accommodate the disease conditions pertaining to many organs; and in the case of this review, the lung. Lung-on-a-chip models result in a more accurate reflection compared to conventional in vitro models. Pharmaceutical drug testing methods traditionally use animal models in order to evaluate pharmacological and toxicological responses to a new agent. However, these responses do not directly reflect human physiological responses. In this review, current and future applications of the lung-on-a-chip in the respiratory system will be discussed. Furthermore, the limitations of current conventional in vitro models used for respiratory disease modeling and drug development will be addressed. Highlights of additional translational aspects of the lung-on-a-chip will be discussed in order to demonstrate the importance of this subject for medical research.

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.

Eosinophilic airway inflammation is a main feature of unstable asthma in adolescents

BACKGROUND

Stability of asthma is a clinical phenotype of the disease based on long-term evaluation of control of asthma symptoms and its exacerbations. A relationship between airway inflammation and clinical classification of asthma based on stability criterion has not been well studied.

OBJECTIVES

The purpose of our study was to analyze the inflammation profile of stable and unstable asthma in adolescents treated with moderate and high doses of inhaled corticosteroids.

METHODS

139 young asthmatics of 16.8 (3.25) years were classified in the stable group (N = 72) and unstable group (N = 67) after a 3-month prospective observation. Inflammatory markers including cytogram of the induced sputum (IS), fractional exhaled nitric oxide (FeNO) and bronchial hyperresponsiveness (BHR) following provocation with hypertonic saline and exercises, as well as clinical and spirometric parameters in both groups were compared.

RESULTS

75% of patients with unstable asthma revealed elevated percentage of eosinophils in the induced sputum (>2.5%), and mean values were significantly higher in comparison with stable asthma: 2.0 (0,5-4,2) vs 5,5 (2,6-11,3), p < 0,001. Bronchial hyperresponsiveness was markedly higher in unstable asthma, especially in asthma with eosinophilic profile; statistically significant differences also related to functional pulmonary tests. In multivariate analysis, asthma instability was significantly associated with sEos (p = 0.005), BHR (p = 0.001) but not FeNO (p = 0.24).

CONCLUSION (AND CLINICAL RELEVANCE)

Eosinophilic inflammation, relatively resistant to high doses of inhaled corticosteroids, is a dominant type of inflammation in unstable asthma in adolescents. Asthma instability is also associated with higher bronchial hyperresponsiveness and lower spirometric parameters. In the light of the new studies and progress in biological methods of therapy of eosinophilic inflammation, unstable asthma, especially in case of severe course, requires extended diagnostics with determination of inflammatory phenotype.

Adherence to medication in children and adolescents with asthma: methods for monitoring and intervention

INTRODUCTION

Poor adherence in children with asthma is a major cause of asthma attacks and poor control, leads to large health-care costs, and has been identified as a factor in asthma deaths. However, it is difficult to detect and frequently overlooked leading to inappropriate escalation of asthma treatment. There is a need for cost effective ways to monitor adherence in order to intervene to change this modifiable behavior. Areas covered: Several measurement tools have been developed to assess adherence in adults and children with asthma. The current methods for measuring adherence, both subjective and objective, have several flaws and even the current gold standard, electronic monitoring devices (EMDs), has limitations. This review will outline and critique the adherence monitoring tools and highlight ways in which they have been used for the purpose of intervention. Expert commentary: Although advances have been made in adherence monitoring, we still have some way to go in creating the ideal monitoring tool. There are no validated tailored self-monitoring questionnaires for children with asthma and most objective measures, such as prescription refill rate and weighing canisters, overestimate adherence. Current EMDs, although useful, need improved accuracy to ensure that both actuation and inhalation are measured, and the devices need to be affordable for use in routine health-care practice.

Advanced Microengineered Lung Models for Translational Drug Discovery

Lung diseases impose a significant socioeconomic burden and are a leading cause of morbidity and mortality worldwide. Moreover, respiratory medicine, unlike several other therapeutic areas, faces a disappointingly low number of new approved therapies. This is partly due to lack of reliable in vitro or in vivo models that can reproduce organ-level complexity and pathophysiological responses of human lung. Here, we examine new opportunities in application of recently emerged organ-on-chip technology to model human lung alveolus and small airway in preclinical drug development and biomarker discovery. We also discuss challenges that need to be addressed in coming years to further enhance the physiological and clinical relevance of these microsystems, enable their increased accessibility, and support their leap into personalized medicine.

Severe asthma in children

Most children with asthma have their disease easily controlled if low-dose inhaled corticosteroids (ICSs) are regularly and correctly administered. If a child presents with asthma which is apparently resistant to therapy with high-dose ICS and other controllers, then they have problematic severe asthma. However, in light of the UK National Review of Asthma Deaths, definitions of severe asthma based solely on the levels of prescribed treatment are too narrow. A detailed assessment of all such children should be performed. First, the diagnosis of asthma should be confirmed, then co-morbidities assessed. Next, a nurse-led assessment further characterizes the problem, conventionally categorizing the child as either having difficult asthma or severe therapy-resistant asthma. Here, we reassess in particular the interactions between, and management of, these two categories, highlighting that this dichotomous classification may need reconsideration. We use bronchoscopy and an intramuscular steroid injection to determine if the child has steroid-resistant asthma, using a novel, multidomain approach because the adult definition does not apply to around half the children we see. Finally, we highlight some mechanistic data which have emerged from this protocol such as the absence of T-helper 2 (TH2) cytokines even in eosinophilic severe asthma and the potential role of the innate epithelial cytokine IL-33, novel data on lineage negative innate lymphoid cells, which we can measure in induced sputum, and demonstrating that intraepithelial neutrophils are associated with better, not worse asthma outcomes. Severe paediatric asthma is very different from severe asthma in adults, and approaches must not be uncritically extrapolated from adult disease to children.

MARKERS OF ATOPIC REACTIVITY IN THE PUPILS WITH SEVERE BRONCHIAL ASTHMA

The aim of the work was to increase the effectiveness of treatment of the severe asthma phenotype in school-age children, taking into account the diagnostic value of atopic reactivity indicators. The study involved 30 pupils with severe asthma and 30 children with moderate-heavy version of it. Amid severe asthma increases risk of higher concentrations of IL-4 and IL-5 in the serum, and almost in every second child was observed the increased concentrations of Ig E (more than 545,3 IU/mL, odds ratio was 1,9 (95 % CI 1,1-3,4). In the group of patients with severe asthma were significantly more frequent cases of the skin hypersensitivity to household allergens with respect to the members of the second group. There were separated the indices of clinical and epidemiological risk and diagnostic value of some markers of atopic reactivity for verification of the severe asthma phenotype. It was established that the development of severe asthma in children marked tendency to reduce the metabolic activity of eosinophilic granulocytes in blood (in terms of intracellular content of cationic proteins and peroxidase) and phagocytic ability of these effector cells of allergic inflammation. For the phenotype of severe asthma the risk of high concentration of IL-4 and IL-5 in serum increased in 3,1 times, but this paraclinical test is rather suitable for verification of this phenotype (SP – 84,6% (95 % Sp 75,9–91,1)) than for its detection (Se – 36,4 % (95 % CI 26,9–46,6)).

COMPARISON OF THE DYNAMIC CHANGES OF AMINO ACID BLOOD PLASMA SPECTRUM IN PATIENTS WITH THE PRIMARY CEREBRAL ISCHEMIC STROKE DEPENDING ON THE POSTAPOPLECTIC SPASTICITY DEVELOPMENT IN THE RECOVERY PERIOD

The aim of research was to reveal the dynamic changes of the level of excitatory and inhibitory neuroamino acids in patients with the primary cerebral ischemic stroke depending on postapoplectic spasticity presence at the end of the early recovery period. For this aim was studied the concentration of excitatory and inhibitory neuroamino acids in the blood plasma in first 72 hours in 97 patients with the primary ischemic cerebral stroke depending on postapoplectic spasticity on the sixth month after ischemic event. The control group included 15 patients with diagnosed chronic cerebral ischemia. In the result of research we revealed that the common sign for the two groups (with spasticity on the sixth month and without it) was the reliable rise of the level of excitatory amino acids comparing with the control. In patients without spasticity the heightened level of excitatory neurotransmitters in the most acute period of ischemic cerebral stroke was attended with the heightened level of inhibitory neuroamino acids. The distinctive feature of patients with postapoplectic spasticity was the decreased or stable level of transmitters of inhibitory action. During 6th moth after ischemic stroke was detected the rise of all studied neuroamino acids in patients with spasticity unlike to the ones without spasticity who were characterized only with the rise of taurine level and decrease of glycine and aspartate levels. So, the received results allow assume the insufficient activation of the inhibitory neuroamino acids system in the most acute period of the ischemic stroke in certain category of patients that in future are inclined to the spasticity development after stroke.

Assessment of corticosteroid response in pediatric patients with severe asthma by using a multidomain approach

BACKGROUND

There is no agreed upon definition of systemic corticosteroid response in asthmatic children. Moreover, pediatric severe therapy-resistant asthma (STRA) is heterogeneous, and thus response to steroids is unlikely to be uniform in all patients.

OBJECTIVE

We sought to evaluate the utility of a multidomain approach incorporating symptoms, lung function, and inflammation to determine steroid responsiveness in pediatric patients with STRA.

METHODS

Eighty-two children (median age, 12 years) with STRA received a clinically indicated dose of intramuscular steroid. Changes in 4 separate domains were assessed 4 weeks after intramuscular triamcinolone acetonide: normalization of (1) symptoms (Asthma Control Test score, >19/25 or 50% increase), (2) spirometric results (FEV1 ≥80% of predicted value or ≥15% increase), (3) fraction of exhaled nitric oxide levels (<24 ppb), and (4) sputum eosinophil counts (<2.5%). Fifty-four of 82 children had complete data in all 4 domains.

RESULTS

Twenty-three (43%) of 54 children had a symptom response, 29 (54%) of 54 had a lung function response, 28 (52%) of 54 had a fraction of exhaled nitric oxide response, and 29 (54%) of 54 had a sputum eosinophil response. Although a similar proportion of children responded to systemic corticosteroids in each domain, there were no reliable predictors of a response pattern. Seven (13%) of 54 were complete responders (response in all domains), 8 (15%) of 54 were nonresponders (no response in any domain), and 39 (72%) of 54 were partial responders (response in ≥1 domain).

CONCLUSIONS

A multidomain evaluation of systemic steroid responsiveness using pragmatic clinical assessments confirms childhood STRA is heterogeneous and that a complete response in symptoms and inflammatory and physiologic parameters is rare. Individual response patterns to systemic steroids might be useful in guiding the choice of add-on therapies in each child as a step toward achieving personalized medicine.

Ethnic Variation in Response to IM Triamcinolone in Children With Severe Therapy-Resistant Asthma

BACKGROUND

Although ethnicity may influence response to treatment of patients with asthma, this approach is controversial. The objective of this study was to determine if ethnicity influences the response to IM steroid use (eliminating adherence as an issue).

METHODS

Children with severe therapy-resistant asthma who had previously undergone a detailed assessment (including a nurse-led hospital and home visit in which potentially modifiable factors had been identified and addressed) were admitted for further evaluation; this evaluation included assessment of steroid response. Children were classified as white, black, Asian, or mixed white/black. Steroid responsiveness was defined according to symptoms (Asthma Control Test), inflammation (sputum eosinophil count and exhaled nitric oxide), and spirometry (FEV1); these variables were measured before and 4 weeks after IM triamcinolone use. Data were collected regarding exacerbations. Fractional exhaled nitric oxide (Feno) response was defined as a decrease to < 24 parts per billion (ppb).

RESULTS

Seventy-nine subjects were identified (white, n = 54 [68%]; black, n = 16 [20%]; Asian, n = 5 [6%]; and mixed white/black, n = 4 [5%]). After administration of triamcinolone, there was a significant drop in median Feno in white children (46.8 to 23.1 ppb; P < .001) but not in black children (52.2 to 34.5 ppb; P = .58). More black children than white children (86.7%) were Feno nonresponders (86.7% vs 45.3%; P < .05), and more black children had exacerbations compared with white children (61% vs 17%; P < .05).

CONCLUSIONS

Black children with asthma were less likely to report an Feno response and had more exacerbations 4 weeks after administration of triamcinolone than white children. Further research is needed to understand the mechanisms of these differences, but they cannot be due to differences in adherence or access to care.

Ground zero: not asthma at all

Upper airway obstruction is commonly misdiagnosed as asthma. We report on four children with recurrent respiratory symptoms who had been erroneously diagnosed as having asthma and who received anti-asthma medication for several years. The evaluation of spirometry tracing was neglected in all cases. Subglottic stenosis, tracheomalacia secondary to tracheo-esophageal fistula, double aortic arch, and vocal cord dysfunction were suspected by direct inspection of the flow-volume curves and eventually diagnosed. The value of clinical history and careful evaluation of spirometry tracing in children with persistent respiratory symptoms is critically discussed.

Severe asthma in children

Severe asthma in children is characterized by sustained symptoms despite treatment with high doses of inhaled corticosteroids or oral corticosteroids. Children with severe asthma may fall into 2 categories, difficult-to-treat asthma or severe therapy-resistant asthma. Difficult-to-treat asthma is defined as poor control due to an incorrect diagnosis or comorbidities, or poor adherence due to adverse psychological or environmental factors. In contrast, treatment resistant is defined as difficult asthma despite management of these factors. It is increasingly recognized that severe asthma is a highly heterogeneous disorder associated with a number of clinical and inflammatory phenotypes that have been described in children with severe asthma. Guideline-based drug therapy of severe childhood asthma is based primarily on extrapolated data from adult studies. The recommendation is that children with severe asthma be treated with higher-dose inhaled or oral corticosteroids combined with long-acting β-agonists and other add-on therapies, such as antileukotrienes and methylxanthines. It is important to identify and address the influences that make asthma difficult to control, including reviewing the diagnosis and removing causal or aggravating factors. Better definition of the phenotypes and better targeting of therapy based upon individual patient phenotypes is likely to improve asthma treatment in the future.

Management of severe asthma in childhood--state of the art and novel perspectives

The majority of children with asthma have mild or moderate disease and can obtain adequate control of symptoms through avoidance of triggering factors and/or with the help of medications. There is still a group of children with severe asthma in whom symptom control is poor depending either on identifiable aggravating factors or on true therapy resistance. These children have a poor quality of life and are limited by the severity of their disease. There is a need for a staged approach to the assessment and treatment of this small but vulnerable and resource-consuming group. The current review will provide an overview of a possible standardized approach to characterize this heterogeneous group of severely sick children including some newly developed ways of assessing asthma severity and potentialities of new asthma therapies. Furthermore, the umbrella term 'problematic severe asthma' is described. The term encompasses children whose severe asthma is due to identifiable exacerbating factors, as well as children who are resistant to any conventional therapeutic approach. Characteristics of these two groups of children are described, as are possible biomarkers and current and emerging diagnostic tools for allergy evaluation. Some recent advances and future possibilities for treatment of severe asthma are also presented in this review.

Joint modeling of parentally reported and physician-confirmed wheeze identifies children with persistent troublesome wheezing

BACKGROUND

Previous studies have suggested the presence of different childhood wheeze phenotypes through statistical modeling based on parentally reported wheezing.

OBJECTIVE

We sought to investigate whether joint modeling of observations from both medical records and parental reports helps to more accurately define wheezing disorders during childhood and whether incorporating information from medical records better characterizes severity.

METHODS

In a population-based birth cohort (n = 1184), we analyzed data from 2 sources (parentally reported current wheeze at 4 follow-ups and physician-confirmed wheeze from medical records in each year from birth to age 8 years) to determine classes of children who differ in wheeze trajectories. We tested the validity of these classes by examining their relationships with objective outcomes (lung function, airway hyperreactivity, and atopy), asthma medication, and severe exacerbations.

RESULTS

Longitudinal latent class modeling identified a 5-class model that best described the data. We assigned classes as follows: no wheezing (53.3%), transient early wheeze (13.7%), late-onset wheeze (16.7%), persistent controlled wheeze (13.1%), and persistent troublesome wheeze (PTW; 3.2%). Longitudinal trajectories of atopy and lung function differed significantly between classes. Patients in the PTW class had diminished lung function and more hyperreactive airways compared with all other classes. We observed striking differences in exacerbations, hospitalizations, and unscheduled visits, all of which were markedly higher in patients in the PTW class compared with those in the other classes. For example, the risk of exacerbation was much higher in patients in the PTW class compared with patients with persistent controlled wheeze (odds ratio [OR], 3.58; 95% CI, 1.27-10.09), late-onset wheeze (OR, 15.92; 95% CI, 5.61-45.15), and transient early wheeze (OR, 12.24; 95% CI, 4.28-35.03).

CONCLUSION

We identified a novel group of children with persistent troublesome wheezing, who have markedly different outcomes compared with persistent wheezers with controlled disease.

The chitinase-like protein YKL-40: a possible biomarker of inflammation and airway remodeling in severe pediatric asthma

BACKGROUND

Problematic severe childhood asthma includes a subgroup of patients who are resistant to therapy. The specific mechanisms involved are unknown, and novel biomarkers are required to facilitate treatment and diagnosis of therapy-resistant asthma. The chitinase-like protein YKL-40 has been related to asthma and airway remodeling.

OBJECTIVES

To compare serum YKL-40 levels in children with severe, therapy-resistant asthma (n = 34), children with controlled persistent asthma (n = 39), and healthy controls (n = 27), and to investigate correlations with biomarkers of inflammation and airway remodeling.

METHODS

The study protocol included questionnaires, measurement of exhaled nitric oxide in exhaled air, blood sampling for inflammatory biomarkers, and high-resolution computed tomography of the lungs to identify bronchial wall thickening (therapy-resistant only). Serum YKL-40 levels were measured by ELISA, and all asthmatic children were genotyped for a CHI3L1 promoter single nucleotide polymorphism (rs4950928).

RESULTS

Serum YKL-40 levels were significantly higher in children with therapy-resistant asthma than in healthy children (19.2 ng/mL vs 13.8 ng/mL, P = .03). Among children with severe, therapy-resistant asthma, YKL-40 levels correlated with fraction of exhaled nitric oxide in exhaled air (r = 0.48, P = .004), blood neutrophils (r = 0.63, P < .001), and bronchial wall thickening on high-resolution computed tomography (r = 0.45, P = .01). Following adjustment for CHI3L1 genotype, significantly greater levels of YKL-40 were found in children with therapy-resistant asthma than in children with controlled asthma.

CONCLUSIONS

YKL-40 levels are increased in children with severe, therapy-resistant asthma compared to healthy children, and also compared to children with controlled asthma following correction for genotype.

Asthma severity in childhood and metabolomic profiling of breath condensate

BACKGROUND

Asthma is a heterogeneous disease and its different phenotypes need to be better characterized from a biochemical-inflammatory standpoint. This study aimed to apply the metabolomic approach to exhaled breath condensate (breathomics) to discriminate different asthma phenotypes, with a particular focus on severe asthma in children.

METHODS

In this cross-sectional study, we recruited 42 asthmatic children (age, 8-17 years): 31 with nonsevere asthma (treated with inhaled steroids or not) and 11 with severe asthma. Fifteen healthy children were enrolled as controls. Children performed exhaled nitric oxide measurement, spirometry, exhaled breath condensate (EBC) collection. Condensate samples were analyzed using a metabolomic approach based on mass spectrometry.

RESULTS

A robust Bidirectional-Orthogonal Projections to Latent Structures-Discriminant Analysis (O2PLS-DA) model was found for discriminating both between severe asthma cases and healthy controls (R(2)  = 0.93; Q(2)  = 0.75) and between severe asthma and nonsevere asthma (R(2)  = 0.84; Q(2)  = 0.47). The metabolomic data analysis leads to a robust model also when the 3 groups of children were considered altogether (K = 0.80), indicating that each group is characterized by a specific metabolomic profile. Compounds related to retinoic acid, adenosine and vitamin D (Human Metabolome Database) were relevant for the discrimination between groups.

CONCLUSION

The metabolomic profiling of EBC could clearly distinguish different biochemical-metabolic profiles in asthmatic children and enabled the severe asthma phenotype to be fully discriminated. The breathomics approach may therefore be suitable for discriminating between different asthma metabolic phenotypes.

Pediatric severe asthma is characterized by eosinophilia and remodeling without T(H)2 cytokines

BACKGROUND

The pathology of pediatric severe therapy-resistant asthma (STRA) is little understood.

OBJECTIVES

We hypothesized that STRA in children is characterized by airway eosinophilia and mast cell inflammation and is driven by the T(H)2 cytokines IL-4, IL-5, and IL-13.

METHODS

Sixty-nine children (mean age, 11.8 years; interquartile range, 5.6-17.3 years; patients with STRA, n = 53; control subjects, n = 16) underwent fiberoptic bronchoscopy, bronchoalveolar lavage (BAL), and endobronchial biopsy. Airway inflammation, remodeling, and BAL fluid and biopsy specimen T(H)2 cytokines were quantified. Children with STRA also underwent symptom assessment (Asthma Control Test), spirometry, exhaled nitric oxide and induced sputum evaluation.

RESULTS

Children with STRA had significantly increased BAL fluid and biopsy specimen eosinophil counts compared with those found in control subjects (BAL fluid, P < .001; biopsy specimen, P < .01); within the STRA group, there was marked between-patient variability in eosinophilia. Submucosal mast cell, neutrophil, and lymphocyte counts were similar in both groups. Reticular basement membrane thickness and airway smooth muscle were increased in patients with STRA compared with those found in control subjects (P < .0001 and P < .001, respectively). There was no increase in BAL fluid IL-4, IL-5, or IL-13 levels in patients with STRA compared with control subjects, and these cytokines were rarely detected in induced sputum. Biopsy IL-5(+) and IL-13(+) cell counts were also not higher in patients with STRA compared with those seen in control subjects. The subgroup (n = 15) of children with STRA with detectable BAL fluid T(H)2 cytokines had significantly lower lung function than those with undetectable BAL fluid T(H)2 cytokines.

CONCLUSIONS

STRA in children was characterized by remodeling and variable airway eosinophil counts. However, unlike in adults, there was no neutrophilia, and despite the wide range in eosinophil counts, the T(H)2 mediators that are thought to drive allergic asthma were mostly absent.

The clinical benefit of evaluating health-related quality-of-life in children with problematic severe asthma

AIM

To evaluate health-related quality-of-life (HR-QoL) and the asthma control test (ACT) in children with problematic severe asthma and those with controlled asthma and to identify whether clinical characteristics show correlations with these measurements.

METHODS

This multicentre cross-sectional study included 93 children in total, 54 with problematic severe asthma and 39 age-matched with controlled asthma. Subjects completed the Paediatric Asthma Quality-of-Life Questionnaire as well as a standardized health questionnaire and the ACT. Objective measurements of exhaled nitric oxide, specific sensitization, pulmonary function and bronchial hyper-responsiveness to methacholine were also taken.

RESULTS

HR-QoL was reduced in children with problematic severe asthma (5.4 vs. 6.7, p < 0.001), particularly for girls (5.1 vs. 5.6 for boys, p = 0.02), and their ACT scores were also lower (17 vs. 23, p < 0.001) compared with those of subjects with controlled asthma. A HR-QoL score <6.2 discriminated problematic severe asthma from controlled asthma with 85% sensitivity and 97% specificity, as did the ACT score <20 (79% sensitivity and 94% specificity). Objective measures and other clinical characteristics were weakly associated with HR-QoL or ACT score.

CONCLUSION

Subjective measurements of HR-QoL and asthma control are both equally useful in differentiating children with problematic severe asthma from those with controlled asthma.

WHO universal definition of severe asthma

PURPOSE OF REVIEW

In 2009, an expert panel met to propose a WHO definition of asthma severity and control, and criteria for describing exacerbations and their severity, which would be globally applicable. This review addresses their findings in the context of recent literature, and assesses the usefulness of these definitions in children in particular.

RECENT FINDINGS

Severe asthma was defined by the level of current clinical control and risks as: 'Uncontrolled asthma which can result in risk of frequent severe exacerbations (or death) and/or adverse reactions to medications and/or chronic morbidity (including impaired lung function or reduced lung growth in children)'. Severe asthma includes three groups, with different public health messages and challenges: untreated severe asthma, due to undiagnosed asthma or unavailability of therapy, difficult-to-treat severe asthma (due to adherence issues, inappropriate or incorrect use of medicines, environmental triggers or co-morbidity), and treatment-resistant severe asthma, including asthma for which control is not achieved despite the highest level of recommended treatment or asthma which is controlled only with the highest level of recommended treatment.

SUMMARY

These definitions will enable more precise measurement of the burden of severe childhood asthma globally. International collaborations in epidemiological and mechanistic studies, and randomized controlled trials of treatment, will be facilitated. However, both pathophysiology and severity are influenced by a number of factors with wide global variation; international comparisons should be interpreted with caution.

Clinical, radiological, and physiological differences between obliterative bronchiolitis and problematic severe asthma in adolescents and young adults: the early origins of the overlap syndrome?

PURPOSE

Few reports have compared chronic obstructive lung diseases (OLDs) starting in childhood.

AIMS

To describe functional, radiological, and biological features of obliterative bronchiolitis (OB) and further discriminate to problematic severe asthma (PSA) or to diagnose a group with overlapping features.

RESULTS

Patients with OB showed a greater degree of obstructive lung defect and higher hyperinflation (P < 0.001). The most frequent high-resolution computed tomography (HRCT) features (increased lung volume, inspiratory decreased attenuation, mosaic pattern, and expiratory air trapping) showed significantly greater scores in OB patients. Patients with PSA have shown a higher frequency of atopy (P < 0.05). ROC curve analysis demonstrated discriminative power for the LF variables, HRCT findings and for atopy between diagnoses. Further analysis released five final variables more accurate for the identification of a third diagnostic group (FVC%t, post-bronchodilator ΔFEV(1) in ml, HRCT mosaic pattern, SPT, and D. pteronyssinus-specific IgE).

CONCLUSIONS

We found that OB and PSA possess identifiable characteristic features but overlapping values may turn them undistinguishable.

Problematic severe asthma: a proposed approach to identifying children who are severely resistant to therapy

Children with problematic severe asthma (PA) are either difficult to treat because of the presence of aggravating factors or else severely resistant to therapy. We investigated a cohort of school-aged children with PA and compared these children to age-matched peers with controlled persistent asthma (CA). The aims were to characterize features of children suffering from PA and identify children who were severely resistant to therapy. In this cross-sectional, multicenter comparison of children with different manifestations of persistent asthma, PA was defined as insufficient asthma control despite level 4 treatment, according to GINA. The protocol included questionnaires, spirometry, methacholine provocation, measurement of fraction of nitric oxide in exhaled (FE(NO) ) and nasal air, blood sampling for inflammatory biomarkers and atopy, and computerized tomography of sinuses and lungs (in the PA group only). Of the 54 children with PA, 61% had therapy-resistant asthma, with the remaining being difficult to treat because of identified aggravating factors. Children with PA more often had parents with asthma (p=0.003), came from families with a lower socioeconomic status (p=0.01), were less physically active (p=0.04), and had more comorbidity with rhinoconjunctivitis (p=0.01) than did the 39 children with CA. The former also exhibited lower FEV(1) values (p=0.02) and increased bronchial hyper-responsiveness (p=0.01), but there were no differences in atopy (p=0.81) or FE(NO) (p=0.16). A non-invasive protocol, involving a standardized and detailed clinical characterization, revealed distinguishing features of children with PA and enabled the identification of children with therapy-resistant asthma.

Uniform definition of asthma severity, control, and exacerbations: document presented for the World Health Organization Consultation on Severe Asthma

Asthma is a global health problem affecting around 300 million individuals of all ages, ethnic groups and countries. It is estimated that around 250,000 people die prematurely each year as a result of asthma. Concepts of asthma severity and control are important in evaluating patients and their response to treatment, as well as for public health, registries, and research (clinical trials, epidemiologic, genetic, and mechanistic studies), but the terminology applied is not standardized, and terms are often used interchangeably. A common international approach is favored to define severe asthma, uncontrolled asthma, and when the 2 coincide, although adaptation may be required in accordance with local conditions. A World Health Organization meeting was convened April 5-6, 2009, to propose a uniform definition of severe asthma. An article was written by a group of experts and reviewed by the Global Alliance against Chronic Respiratory Diseases review group. Severe asthma is defined by the level of current clinical control and risks as "Uncontrolled asthma which can result in risk of frequent severe exacerbations (or death) and/or adverse reactions to medications and/or chronic morbidity (including impaired lung function or reduced lung growth in children)." Severe asthma includes 3 groups, each carrying different public health messages and challenges: (1) untreated severe asthma, (2) difficult-to-treat severe asthma, and (3) treatment-resistant severe asthma. The last group includes asthma for which control is not achieved despite the highest level of recommended treatment and asthma for which control can be maintained only with the highest level of recommended treatment.

Eoxins: a new inflammatory pathway in childhood asthma

BACKGROUND

Increased levels of leukotrienes (LTs) in exhaled breath condensate (EBC) are associated with asthma and bronchial hyperresponsiveness (BHR), whereas eicosanoids generated through the 15-lipoxygenase (LO) pathway (15-hydroxyeicosatetraenoic acid [HETE] and eoxins) have been less studied.

OBJECTIVE

We investigated whether metabolites of the 5- and 15-LO pathways in EBC are associated with childhood asthma, asthma severity, and clinical parameters.

METHODS

The present study included 131 school-aged children (27 children with problematic severe asthma, 80 children with mild-to-moderate asthma, and 24 healthy children) from the Severe Asthma Recognized in Childhood study and 19 children with other nonasthmatic chronic lung diseases. Clinical work-up included spirometry, fractional exhaled nitric oxide measurements, skin prick testing, and methacholine challenge. Eicosanoids were analyzed in EBC by using mass spectrometry and are reported as concentrations (in picograms per milliliter) and eicosanoid/palmitic acid (PA) ratios.

RESULTS

Eoxin C₄/PA, eoxin D₄/PA, eoxin E₄/PA, 15-HETE/PA, and LTC₄/PA ratios were significantly increased in asthmatic versus healthy children. Eoxin D₄/PA and LTE₄/PA ratios were also significantly higher in children with BHR. A nonsignificant trend was observed toward higher eoxin/PA ratios with increasing asthma severity. In contrast to asthma, children with chronic lung disease had the highest 15-HETE/PA, LTC₄/PA, LTE₄/PA, and LTB₄/PA ratios.

CONCLUSION

The results point to increased activity of the 15-LO inflammatory pathway in childhood asthma. Mass spectrometric analyses of EBC demonstrate that increased eoxin levels not only accompany the increased 5-LO product LTC₄ but are also associated with BHR. These markers might represent a new therapeutic target for asthma treatment.

Management of severe asthma in children

Children who are referred to specialist care with asthma that does not respond to treatment (problematic severe asthma) are a heterogeneous group, with substantial morbidity. The evidence base for management is sparse, and is mostly based on data from studies in children with mild and moderate asthma and on extrapolation of data from studies in adults with severe asthma. In many children with severe asthma, the diagnosis is wrong or adherence to treatment is poor. The first step is a detailed diagnostic assessment to exclude an alternative diagnosis ("not asthma at all"), followed by a multidisciplinary approach to exclude comorbidities ("asthma plus") and to assess whether the child has difficult asthma (improves when the basic management needs, such as adherence and inhaler technique, are corrected) or true, therapy-resistant asthma (still symptomatic even when the basic management needs are resolved). In particular, environmental causes of secondary steroid resistance should be identified. An individualised treatment plan should be devised depending on the clinical and pathophysiological characterisation. Licensed therapeutic approaches include high-dose inhaled steroids, the Symbicort maintenance and reliever (SMART) regimen (with budesonide and formoterol fumarate), and anti-IgE therapy. Unlicensed treatments include methotrexate, azathioprine, ciclosporin, and subcutaneous terbutaline infusions. Paediatric data are needed on cytokine-specific monoclonal antibody therapies and bronchial thermoplasty. However, despite the interest in innovative approaches, getting the basics right in children with apparently severe asthma will remain the foundation of management for the foreseeable future.

Asthma severity in childhood, untangling clinical phenotypes

Assessment of childhood asthma severity and asthma control encompasses heterogeneous clinical presentations. The relationship between patterns of asthma symptoms and objective measurements is poorly defined in paediatric asthma. This study includes 115 asthmatic schoolchildren, of which 31 were at inclusion defined as Problematic severe asthma because of inadequate asthma control in the presence of high-dose inhaled corticosteroid (HD-ICS) treatment and at least one other asthma controller drug. Two partially overlapping clinical outcomes were defined irrespective of severity classification (Exacerbations and Chronic persistent asthma) in patients with uncontrolled asthma. The same symptom criteria were used as for Problematic severe asthma, but disregarding current medication. Lung function, exhaled nitric oxide (FE(NO)), bronchial hyperresponsiveness, allergic sensitization and Quality of life (QoL) in the symptom subgroups were compared to children with well-controlled asthma. Multifactor analysis was performed to assess the relative explanatory power of clinical asthma presentations and of HD-ICS treatment on objective measurements. Whereas children included in the Exacerbations subgroup had objective features similar to patients with well-controlled asthma, the Chronic persistent asthma subgroup demonstrated significantly reduced lung function, increased immunoglobin E, allergic poly-sensitization and impaired QoL, similar to that in patients pre-defined as Problematic severe asthma. The presence of chronic asthma symptoms was a significant explanatory factor for reduced lung function, QoL and increased FE(NO) in multifactor analysis. Differences in objective measurements suggest that children with Chronic persistent asthma and those who are symptomatic predominantly during exacerbations may represent distinct phenotypes of childhood asthma with different clinical prognoses.

Omalizumab in children with inadequately controlled severe allergic (IgE-mediated) asthma

BACKGROUND

Many children with severe persistent allergic (IgE-mediated) asthma remain inadequately controlled despite treatment with high-dose inhaled corticosteroids (ICS) plus a long-acting beta(2)-agonist (LABA).

RESEARCH AND DESIGN METHODS

This pre-specified analysis of a randomized, double-blind, placebo-controlled trial evaluated the efficacy and safety of omalizumab in children (6-<12 years) with perennial allergen sensitivity, and history of asthma exacerbations and symptoms despite treatment with ICS (fluticasone >or=500 microg x day(-1) or equivalent) plus a LABA. Patients received omalizumab (75-375 mg once or twice a month by subcutaneous injection, as determined from dosing tables) or placebo over 52 weeks (24-week fixed-steroid then 28-week adjustable-steroid phases).

RESULTS

Out of 246 randomized patients (omalizumab, n = 166; placebo, n = 80), efficacy was analysed in 235 (omalizumab, n = 159; placebo, n = 76). Over the 24-week fixed-steroid phase, omalizumab reduced the rate of clinically significant asthma exacerbations (worsening symptoms requiring doubling of baseline ICS dose and/or systemic steroids) by 34% versus placebo (0.42 vs 0.63, rate ratio 0.662; P = 0.047). Over 52 weeks, the exacerbation rate was reduced by 50% (P < 0.001). Omalizumab had an acceptable safety profile, with no statistically significant (P < 0.05) differences in adverse events observed between omalizumab and placebo.

CONCLUSION

Add-on omalizumab is well-tolerated and reduces exacerbations in children (6-<12 years) with severe persistent allergic asthma, inadequately controlled despite high-dose ICS plus a LABA. It should be noted that the sample size was not based on providing statistical power in the severe subgroup, and no corrections were made for multiple comparisons; however, outcomes consistently favoured omalizumab.

Severe Asthma in Children: Insights from the National Heart, Lung, and Blood Institute's Severe Asthma Research Program

Severe asthma in children is a complicated disorder characterized by ongoing symptoms and persistent airway inflammation despite treatment with high doses of inhaled and oral corticosteroids. Although knowledge of asthma and its associated mechanisms has increased substantially over the past decade, significant gaps remain about the determinants of severe asthma in children and the progression of the disorder across the lifespan. This review highlights recent insights into severe asthma in children derived from the National Heart, Lung, and Blood Institute's Severe Asthma Research Program (SARP), with an emphasis on age-specific findings and differences from severe asthma in adults. While the existence of a true severe asthma phenotype in children is subject to some debate, given the results of SARP and other investigators, we conclude that there is indeed a subgroup of children with severe asthma who have extreme morbidity and differentiating clinical features that are identifiable very early in life. However, unlike adults with severe asthma, children with severe asthma are more likely to fall in a more narrow cluster that is characterized by marked atopy and reversible airflow obstruction. While SARP has advanced knowledge of severe asthma in children, considerable gaps remain for which additional studies are needed.

Identifying problematic severe asthma in the individual child--does lung function matter?

AIM

Measures of lung function (usually FEV(1) <80% predicted) are used to classify asthma severity in both adults and children, despite evidence that lung function impairment is less pronounced in the paediatric asthma population. The present study assesses the relevance of lung function measurements as discriminators of severe childhood asthma.

METHODS

Fifty-one school-aged children with problematic severe asthma, 37 mild-to-moderate asthmatics and 29 healthy controls underwent a comprehensive clinical work-up. Problematic severe asthma was defined in patients exhibiting poor asthma control despite high-dose inhaled corticosteroid treatment and at least one other asthma controller drug. Mild-to-moderate asthmatic children used low-dose inhaled steroids and reported minimal asthma symptoms.

RESULTS

Baseline FEV(1) values were significantly reduced in children with problematic severe asthma, yet FEV(1) <80% predicted showed a low sensitivity (41%) for discriminating severe vs. mild-to-moderate asthma. Receiver-operated characteristic analysis estimated the optimal cut-off of FEV(1) to be 90% predicted in this population (sensitivity 61%, specificity 83%). Baseline FEV(1)/FVC and FEF(25-75) values were not superior to FEV(1) in discriminating problematic severe asthma, and neither exhaled nitric oxide levels nor bronchial hyperresponsiveness differentiated between the two asthmatic study populations.

CONCLUSION

Spirometric measurements are insensitive discriminators of problematic severe asthma in childhood.

Omalizumab for the treatment of exacerbations in children with inadequately controlled allergic (IgE-mediated) asthma

BACKGROUND

Many children with asthma continue to experience symptoms despite available therapies.

OBJECTIVE

This study evaluated the efficacy and safety of omalizumab, a humanized anti-IgE mAb, in children with moderate-to-severe persistent allergic (IgE-mediated) asthma that was inadequately controlled despite treatment with medium-dose or high-dose inhaled corticosteroids (ICSs) with or without other controller medications.

METHODS

A randomized, double-blind, placebo-controlled trial enrolled children age 6 to <12 years with perennial allergen sensitivity and history of exacerbations and asthma symptoms despite at least medium-dose ICSs. Patients were randomized 2:1 to receive omalizumab (75-375 mg sc, q2 or q4 wk) or placebo over a period of 52 weeks (24-week fixed-steroid phase followed by a 28-week adjustable-steroid phase).

RESULTS

A total of 627 patients (omalizumab, n = 421; placebo, n = 206) were randomized, with efficacy analyzed in 576 (omalizumab, n = 384; placebo, n = 192). Over the 24-week fixed-steroid phase, omalizumab reduced the rate of clinically significant asthma exacerbations (worsening symptoms requiring doubling of baseline ICS dose and/or systemic steroids) by 31% versus placebo (0.45 vs 0.64; rate ratio, 0.69; P = .007). Over a period of 52 weeks, the exacerbation rate was reduced by 43% versus placebo (P < .001). Omalizumab significantly reduced severe exacerbations. Over a period of 52 weeks, omalizumab had an acceptable safety profile, with no difference in overall incidence of adverse events compared with placebo.

CONCLUSION

Add-on omalizumab is effective and well tolerated as maintenance therapy in children (6 to <12 years) with moderate-to-severe persistent allergic (IgE-mediated) asthma whose symptoms are inadequately controlled despite medium to high doses of ICSs.

Natural history of lung function in health and diseases

PURPOSE OF REVIEW

To outline major advances in the understanding of factors that influence lung function development through childhood.

RECENT FINDINGS

New study approaches such as adjusting for 'tracking' or analysing without predefined phenotypes suggest that reduced lung function reported with several pre or coexisting features such as lower respiratory tract infections and early allergic sensitization may be spurious rather than causative. Also, two large, recent studies have clearly demonstrated that living close to major roads causes significant lung function deficits in school children, with the possible long-term impact this can have on health in adult life. Furthermore, it is becoming clear that we need to focus upon early life events that can cause harm as well as have a potential for catch-up growth or development in postnatal life.

SUMMARY

The implications of these findings are clearly that there is a potential for intervening in a potential pathological development. Furthermore, there is a clear need to focus research upon early life events that can improve lung growth in the damaged lung and prevent damage to the potentially healthy lung at the very start of life.