Demographic and clinical characteristics of children and adolescents with severe or difficult-to-treat asthma

Prediction of Asthma Exacerbations in Children

Asthma exacerbations are common in asthmatic children, even among those with good disease control. Asthma attacks result in the children and their parents missing school and work days; limit the patient's social and physical activities; and lead to emergency department visits, hospital admissions, or even fatal events. Thus, the prompt identification of asthmatic children at risk for exacerbation is crucial, as it may allow for proactive measures that could prevent these episodes. Children prone to asthma exacerbation are a heterogeneous group; various demographic factors such as younger age, ethnic group, low family income, clinical parameters (history of an exacerbation in the past 12 months, poor asthma control, poor adherence to treatment, comorbidities), Th2 inflammation, and environmental exposures (pollutants, stress, viral and bacterial pathogens) determine the risk of a future exacerbation and should be carefully considered. This paper aims to review the existing evidence regarding the predictors of asthma exacerbations in children and offer practical monitoring guidance for promptly recognizing patients at risk.

Pyrroloquinoline Quinone Administration Alleviates Allergic Airway Inflammation in Mice by Regulating the JAK-STAT Signaling Pathway

The current asthma therapies are inadequate for many patients with severe asthma. Pyrroloquinoline quinone (PQQ) is a naturally-occurring redox cofactor and nutrient that can exert a multitude of physiological effects, including anti-inflammatory and antioxidative effects. We sought to explore the effects of PQQ on allergic airway inflammation and reveal the underlying mechanisms. In vitro, the effects of PQQ on the secretion of epithelial-derived cytokines by house dust mite- (HDM-) incubated 16-HBE cells and on the differentiation potential of CD4+ T cells were investigated. In vivo, PQQ was administered to mice with ovalbumin- (OVA-) induced asthma, and lung pathology and inflammatory cell infiltration were assessed. The changes in T cell subsets and signal transducers and activators of transcription (STATs) were evaluated by flow cytometry. Pretreatment with PQQ significantly decreased HDM-stimulated thymic stromal lymphopoietin (TSLP) production in a dose-dependent manner in 16-HBE cells and inhibited Th2 cell differentiation in vitro. Treatment with PQQ significantly reduced bronchoalveolar lavage fluid (BALF) inflammatory cell counts in the OVA-induced mouse model. PQQ administration also changed the secretion of IFN-γ and IL-4 as well as the percentages of Th1, Th2, Th17, and Treg cells in the peripheral blood and lung tissues, along with inhibition the phosphorylation of STAT1, STAT3, and STAT6 while promoting that of STAT4 in allergic airway inflammation model mice. PQQ can alleviate allergic airway inflammation in mice by improving the immune microenvironment and regulating the JAK-STAT signaling pathway. Our findings suggest that PQQ has great potential as a novel therapeutic agent for inflammatory diseases, including asthma.

Efficacy, safety, and tolerability of lebrikizumab in adolescent patients with uncontrolled asthma (ACOUSTICS)

Background

Lebrikizumab is a monoclonal antibody that modulates activity of interleukin‐13. The Phase 3 ACOUSTICS study assessed lebrikizumab efficacy and safety in adolescents with uncontrolled asthma despite standard‐of‐care treatment.

Methods

Adolescents (aged 12–17 years) with uncontrolled asthma, prebronchodilator forced expiratory volume in 1 s 40%–90% predicted, and stable background therapy were randomised 1:1:1 to receive lebrikizumab 125 or 37.5 mg or placebo subcutaneously once every 4 weeks. Primary efficacy endpoint was asthma exacerbation rate over 52 weeks.

Results

Between August 2013 and July 2016, 579 patients were screened and 346 were randomised; 224 (65%) completed the study with 52 weeks of treatment. Lebrikizumab 125 mg (n = 116) reduced the exacerbation rate at 52 weeks versus placebo (n = 117; adjusted rate ratio [RR] 0.49 [95% CI 0.28–0.83]; 51% rate reduction). Lebrikizumab 37.5 mg (n = 113) was less effective at reducing exacerbations (RR 0.60 [95% CI 0.35–1.03]; 40% rate reduction). In patients with blood eosinophil counts ≥300 cells/μl, both lebrikizumab doses reduced exacerbations (125 mg: RR 0.44 [95% CI 0.21–0.89]; 37.5 mg: 0.42 [95% CI 0.19–0.93]). Treatment‐emergent adverse events, serious adverse events, and adverse events leading to study discontinuation occurred in 155 (68%), 7 (3%), and 5 (2%) of 229 patients who received lebrikizumab (both 125 and 37.5 mg doses) and in 72 (62%), 4 (3%), and 1 (1%) of 117 who received placebo, respectively. No deaths occurred.

Conclusion

Lebrikizumab 125 mg reduced asthma exacerbation rates in adolescents with uncontrolled asthma. However, the study was prematurely terminated (sponsor's decision) potentially limiting interpretation of results.

Clinical trial registration

NCT01875003 (www.ClinicalTrials.gov).

Clinical Experience with Anti-IgE Monoclonal Antibody (Omalizumab) in Pediatric Severe Allergic Asthma-A Romanian Perspective

Background: Asthma is the most common chronic disease affecting children, with a negative impact on their quality of life. Asthma is often associated with comorbid allergic diseases, and its severity may be modulated by immunoglobulin E (IgE)-mediated allergen sensitization. Omalizumab is a humanized monoclonal anti-IgE antibody, the first biological therapy approved to treat patients aged ≥6 years with severe allergic asthma. The primary objective of our study was to investigate the efficacy and safety of Omalizumab in Romanian children with severe allergic asthma. Methods: In this observational real-life study, 12 children and adolescents aged 6 to 18 years (mean 12.4 years) with severe allergic asthma received Omalizumab as an add-on treatment. Asthma control, exacerbations, lung function, and adverse events were evaluated at baseline and after the first year of treatment. Results: We observed general improvement in total asthma symptom scores and reduction in the rate of exacerbation of severe asthma. Omalizumab treatment was associated with improvement in the measures of lung function, and no serious adverse reactions were reported. FEV1 improved significantly after one year of treatment with Omalizumab [ΔFEV1 (% pred.) = 18.3], and [similarly, ΔMEF50 (%) = 25.8]. The mean severe exacerbation rate of asthma decreased from 4.1 ± 2.8 to 1.15 ± 0.78 (p < 0.0001) during the year of treatment with Omalizumab. Conclusions: This study showed that Omalizumab can be an effective and safe therapeutic option for Romanian children and adolescents with severe allergic asthma, providing clinically relevant information on asthma control and exacerbation rate in children and adolescents. The results demonstrated the positive effect of Omalizumab in young patients with asthma, starting from the first year of treatment.

Effects of omalizumab in children with asthma: A protocol for systematic review and meta-analysis

BACKGROUND

It is still controversial in the current literature whether omalizumab is beneficial for children with asthma. Given that there is no high-quality meta-analysis to incorporate existing evidence, the purpose of this protocol is to design a systematic review and meta-analysis of the level I evidence to ascertain whether omalizumab is beneficial and safe for children with asthma.

METHODS

The systematic literature review is structured to adhere to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The following search terms will be used in PUBMED, Scopus, EMBASE, and Cochrane Library databases on June, 2021, as the search algorithm: (omalizumab) AND (asthma) AND (children). The primary outcome is the long-term safety and tolerability of omalizumab. The other outcomes include asthma control, quality of life, use of asthma controller medications, and spirometry measurements and emergency room visits due to asthma, and serum trough concentrations of omalizumab, free and total immunoglobulin E measured. Review Manager software (v 5.3; Cochrane Collaboration) will be used for the meta-analysis.

RESULTS

The review will add to the existing literature by showing compelling evidence and improved guidance in clinic settings.

REGISTRATION NUMBER

10.17605/OSF.IO/G6N3P.

A territory-wide study on the factors associated with recurrent asthma exacerbations requiring hospitalization in Hong Kong

Background

The real‐world relationships between the demographic and clinical characteristics of asthma patients, their prehospitalization management and the frequency of hospitalization due to asthma exacerbation is poorly established.

Objective

To determine the risk factors of recurrent asthma exacerbations requiring hospitalizations and evaluate the standard of baseline asthma care.

Methods

A territory‐wide, multicentre retrospective study in Hong Kong was performed. Medical records of patients aged ≥18 years admitted to 11 acute general hospitals from January 1 to December 31, 2016 for asthma exacerbations were reviewed.

Results

There were 2280 patients with 3154 admissions (36.7% male, median age 66.0 [interquartile range: 48.0–81.0] years, 519 had ≥2 admissions). Among them, 1830 (80.3%) had at least one asthma‐associated comorbidity, 1060 (46.5%) and 885 (38.9%) of patients had Accident and Emergency Department (AED) attendance and hospitalization in the preceding year, respectively. Patients with advancing age (incidence rate ratio [IRR]: 1.003 for every year increment), a history of AED visits or hospitalization (IRR: 1.018 and 1.070 for every additional episode, respectively) for asthma exacerbation in the preceding year, the presence of neuropsychiatric (IRR: 1.142) and gastrointestinal (IRR: 1.154) comorbidities were risk factors for an increasing number of admissions for asthma exacerbation. For patients with ≥2 admissions, 17.1% were not prescribed inhaled corticosteroid and only 44.6% had spirometry checked before the index admission. Asthma phenotyping was often incomplete, as assessment of atopy (total serum immunoglobulin E level and senitization to aeroallergens) was only performed in 30 (5.8%) patients with ≥2 admissions.

Conclusions and Clinical Relevance

Improving asthma care, especially in elderly patients with a prior history of urgent healthcare utilization and comorbidities, may help reduce healthcare burden. Suboptimal management before the index admission was common in patients hospitalized for asthma exacerbations. Early identification of patients at risk and enhancement of baseline asthma management may help to prevent recurrent asthma exacerbation and subsequent hospitalization.

Enhanced airway hyperresponsiveness in asthmatic children and mice with A(H1N1)pdm09 infection

BACKGROUND

Severe asthma exacerbation is an important comorbidity of the 2009 HIN1 pandemic (A(H1N1)pdm09) in asthmatic patients. However, the mechanisms underlying severe asthma exacerbation remain unknown. In this study, airway hyperresponsiveness (AHR) was measured in pediatric asthma patients infected with A(H1N1)pdm09. We also evaluated AHR in asthmatic mice with A(H1N1)pdm09 infection and those with seasonal influenza for comparison.

METHODS

AHRs in asthmatic children were defined as the provocative acetylcholine concentration causing a 20% reduction in forced expiratory volume in 1 s (PC₂₀ ). To investigate the pathophysiology using animal models, BALB/c mice aged 6-8 weeks were sensitized and challenged with ovalbumin. Either mouse-adapted A(H1N1)pdm09, seasonal H1N1 virus (1 × 10⁵ pfu/20 μl), or mock treatment as a control was administered intranasally. At 3, 7, and 10 days after infection, each group of mice was evaluated for AHR by methacholine challenge using an animal ventilator, flexiVent. Lung samples were resected and observed using light microscopy to assess the degree of airway inflammation.

RESULTS

AHRs in the children with bronchial asthma were temporarily increased, and alleviated by 3 months after discharge. AHR was significantly enhanced in A(H1N1)pdm09-infected asthmatic mice compared to that in seasonal H1N1-infected mice (p < .001), peaking at 7 days postinfection and then becoming similar to control levels by 10 days postinfection. Histopathological examination of lung tissues showed more intense infiltration of inflammatory cells and severe tissue destruction in A(H1N1)pdm09-infected mice at 7 days postinfection than at 10 days postinfection.

CONCLUSION

Our results suggest that enhanced AHR could contribute to severe exacerbation in human asthmatic patients with A(H1N1)pdm09 infection.

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

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

Connectivity patterns between multiple allergen specific IgE antibodies and their association with severe asthma

BACKGROUND

Allergic sensitization is associated with severe asthma, but assessment of sensitization is not recommended by most guidelines.

OBJECTIVE

We hypothesized that patterns of IgE responses to multiple allergenic proteins differ between sensitized participants with mild/moderate and severe asthma.

METHODS

IgE to 112 allergenic molecules (components, c-sIgE) was measured using multiplex array among 509 adults and 140 school-age and 131 preschool children with asthma/wheeze from the Unbiased BIOmarkers for the PREDiction of respiratory diseases outcomes cohort, of whom 595 had severe disease. We applied clustering methods to identify co-occurrence patterns of components (component clusters) and patterns of sensitization among participants (sensitization clusters). Network analysis techniques explored the connectivity structure of c-sIgE, and differential network analysis looked for differences in c-sIgE interactions between severe and mild/moderate asthma.

RESULTS

Four sensitization clusters were identified, but with no difference between disease severity groups. Similarly, component clusters were not associated with asthma severity. None of the c-sIgE were identified as associates of severe asthma. The key difference between school children and adults with mild/moderate compared with those with severe asthma was in the network of connections between c-sIgE. Participants with severe asthma had higher connectivity among components, but these connections were weaker. The mild/moderate network had fewer connections, but the connections were stronger. Connectivity between components with no structural homology tended to co-occur among participants with severe asthma. Results were independent from the different sample sizes of mild/moderate and severe groups.

CONCLUSIONS

The patterns of interactions between IgE to multiple allergenic proteins are predictors of asthma severity among school children and adults with allergic asthma.

Efficacy of add-on mepolizumab in adolescents with severe eosinophilic asthma

Adolescents (12-17 years of age) with severe eosinophilic asthma experience frequent exacerbations and reduced lung function leading to poor health-related quality of life. Mepolizumab is approved for add-on maintenance therapy in patients with severe eosinophilic asthma ≥ 6 years of age in the EU and ≥ 12 years of age in other regions (including the USA), based on a Phase II/III program demonstrating reduced exacerbation rates with 4-weekly treatment. A total of 34 adolescent patients were recruited across the Phase III mepolizumab trials. Consistent with outcomes in the overall population, there was a reduction in the annual rate of clinically significant exacerbations, along with a reduction in blood eosinophil counts in response to mepolizumab in adolescent patients. The safety profile in adolescent patients was consistent with that seen in the overall population. Data from the Phase III clinical development program provide evidence for comparable efficacy and safety of mepolizumab between adolescents with severe eosinophilic asthma and the overall population. Clinical trial registration DREAM, NCT01000506 [MEA112997]; MENSA, NCT01691521 [MEA115588]; SIRIUS, NCT01691508 [MEA115575]; MUSCA, NCT02281318 [200862]; COSMOS, NCT01842607 [MEA115661].

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

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

Asthma exacerbation prediction: recent insights

PURPOSE OF REVIEW

Asthma attacks are frequent in children with asthma and can lead to significant adverse outcomes including time off school, hospital admission and death. Identifying children at risk of an asthma attack affords the opportunity to prevent attacks and improve outcomes.

RECENT FINDINGS

Clinical features, patient behaviours and characteristics, physiological factors, environmental data and biomarkers are all associated with asthma attacks and can be used in asthma exacerbation prediction models. Recent studies have better characterized children at risk of an attack: history of a severe exacerbation in the previous 12 months, poor adherence and current poor control are important features which should alert healthcare professionals to the need for remedial action. There is increasing interest in the use of biomarkers. A number of novel biomarkers, including patterns of volatile organic compounds in exhaled breath, show promise. Biomarkers are likely to be of greatest utility if measured frequently and combined with other measures. To date, most prediction models are based on epidemiological data and population-based risk. The use of digital technology affords the opportunity to collect large amounts of real-time data, including clinical and physiological measurements and combine these with environmental data to develop personal risk scores. These developments need to be matched by changes in clinical guidelines away from a focus on current asthma control and stepwise escalation in drug therapy towards inclusion of personal risk scores and tailored management strategies including nonpharmacological approaches.

SUMMARY

There have been significant steps towards personalized prediction models of asthma attacks. The utility of such models needs to be tested in the ability not only to predict attacks but also to reduce them.

Severe Asthma-Perspectives From Adult and Pediatric Pulmonology

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

Airway and esophageal eosinophils in children with severe uncontrolled asthma

AIM

Children with severe uncontrolled asthma (SUA) have a high burden of symptoms and increased frequency of asthma exacerbations. Reflux esophagitis and eosinophilic esophagitis are important co-morbid factors for SUA. Both are associated with the presence of eosinophils in esophageal mucosa. We hypothesized that esophageal eosinophils are frequently present and correlate with the presence of airway eosinophils in children with SUA.

METHOD

We performed a retrospective analysis of a prospective database of children who underwent "triple endoscopy" (sleep laryngoscopy, bronchoscopy with bronchoalveolar lavage [BAL] and endobronchial biopsy [EBB], and esophagogastroduodenoscopy with esophageal biopsy [EsB]) at our Aerodigestive Center for evaluation of SUA. Children with known cystic fibrosis, primary ciliary dyskinesia, and aspiration-related lung disease were excluded.

RESULT

Twenty-four children (21 males) ages 2-16 years were studied. Elevated BAL eosinophils were found in 10 (42%) patients, endobronchial eosinophils in 16 (67%); 7 (29%) had endobronchial eosinophils without elevated BAL eosinophils. Esophageal eosinophils were found in 11 (46%) patients. There was a correlation between the amount of eosinophils in BAL and EBB (R = 0.43, P = 0.05) airway eosinophils, defined as elevated BAL and/or EBB eosinophils, correlated with esophageal eosinophils (R = 0.41, P = 0.047).

CONCLUSION

We concluded that airway and esophageal eosinophils are frequently present in children with SUA.

Monitoring of omalizumab therapy in children and adolescents

BACKGROUND

Omalizumab is a successfully implemented supplementary therapy for improving asthma control in children aged 6 years and older with severe persistent allergic asthma. The dosage of omalizumab depends on body weight and IgE level, yet no parameter has been established to guide dosage changes during therapy. Clinical studies in patients with allergic asthma or allergic rhinitis revealed a clinically relevant improvement by using omalizumab leading to concentrations of free serum IgE reported to be lower than 50 ng/ml. Therefore, only the question concerning the concentrations of free IgE used in a therapy with omalizumab is regarded of clinical importance, while total IgE (free and omalizumab-bound IgE) increases during treatment.

PATIENTS AND METHODS

Ten patients, 8 to 17 years of age, received therapy with omalizumab due to severe allergic asthma. In addition, the patients had pronounced rhinoconjunctivitis, food allergy, insect sting allergy, and/or neurodermitis. The total IgE in the serum was measured in the patients 3 - 6 months before each omalizumab injection as a potential progress parameter (Sandwich-Immunoassay ADVIA Centaur).

RESULTS

Six months after beginning of the therapy with omalizumab, a significant decrease of the total IgE concentration was found, in comparison to the baseline values (p < 0.003). In all patients the tolerability of omalizumab was very good: there was a reduction in the frequency of the asthma exacerbations and rescue medications. All patients reported a clearly improved quality of life.

CONCLUSIONS

A general increase in IgE was not observed in any of the children we treated with omalizumab. Apart from the development of routine assays to determine free serum IgE levels, the significance of the total serum IgE as a suitable control of an omalizumab therapy should be further investigated in controlled studies with regard to sensitivity and specificity. In order to only administer the lowest necessary dose of omalizumab especially in children and adolescents, the establishment of laboratory parameters (free IgE and/or total IgE) to adequately monitor the therapy is urgently needed. Patients undergoing an omalizumab therapy require medical supervision at close intervals.

Can we predict fall asthma exacerbations? Validation of the seasonal asthma exacerbation index

BACKGROUND

A Seasonal Asthma Exacerbation Predictive Index (saEPI) was previously reported based on 2 prior National Institute of Allergy and Infectious Diseases Inner City Asthma Consortium trials.

OBJECTIVE

This study sought to validate the saEPI in a separate trial designed to prevent fall exacerbations with omalizumab therapy.

METHODS

The saEPI and its components were analyzed to characterize those who had an asthma exacerbation during the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations (PROSE) study. We characterized those inner-city children with and without asthma exacerbations in the fall period treated with guidelines-based therapy (GBT) in the absence and presence of omalizumab.

RESULTS

A higher saEPI was associated with an exacerbation in both the GBT alone (P < .001; area under the curve, 0.76) and the GBT + omalizumab group (P < .01; area under the curve, 0.65). In the GBT group, younger age at recruitment, higher total IgE, higher blood eosinophil percentage and number, and higher treatment step were associated with those who had an exacerbation compared with those who did not. In the GBT + omalizumab group, younger age at recruitment, increased eosinophil number, recent exacerbation, and higher treatment step were also associated with those who had an exacerbation. The saEPI was associated with a high negative predictive value in both groups.

CONCLUSIONS

An exacerbation in children treated with GBT with or without omalizumab was associated with a higher saEPI along with higher markers of allergic inflammation, treatment step, and a recent exacerbation. Those that exacerbated on omalizumab had similar features with the exception of some markers of allergic sensitization, indicating a need to develop better markers to predict poor response to omalizumab therapy and alternative treatment strategies for children with these risk factors. The saEPI was able to reliably predict those children unlikely to have an asthma exacerbation in both groups.

Asthma Exacerbations and Triggers in Children in TENOR: Impact on Quality of Life

BACKGROUND

Data examining associations between asthma exacerbations, triggers, and asthma-related quality of life (QOL) in children with severe/difficult-to-treat asthma are unavailable.

OBJECTIVE

To evaluate real-world data on relationships between asthma exacerbations, triggers, and QOL in children using data from TENOR (The Epidemiology and Natural History of Asthma Outcomes and Treatment Regimens), a 3-year observational study of patients with severe/difficult-to-treat asthma, including those aged 6 to 12 years.

METHODS

QOL was examined using the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and defined exacerbations hierarchically (descending order of severity): hospitalization, emergency department visit, steroid burst, no exacerbation, using the highest value from months 6 and 12. One-way ANOVA was used to test for differences in PAQLQ domain scores at month 12 across exacerbation severity, total number of asthma exacerbations, and number of baseline asthma triggers. Mantel-Haenszel chi-square test was used to test the association between the number of triggers and exacerbation hierarchy.

RESULTS

Greater severity of asthma exacerbations was associated with significantly (P < .001) lower mean PAQLQ domain scores, indicating poorer QOL. A higher number of asthma exacerbations was associated with significantly (P < .001) lower mean PAQLQ domain scores. PAQLQ scores were significantly lower with higher numbers of baseline triggers. Higher baseline number of asthma triggers was associated with greater severity (P = .05) and number of asthma exacerbations (P < .001).

CONCLUSIONS

A higher number of asthma triggers at baseline was associated with greater asthma severity and number of asthma exacerbations and lower QOL in children with severe/difficult-to-treat asthma.

Long-term safety, efficacy, pharmacokinetics and pharmacodynamics of omalizumab in children with severe uncontrolled asthma

BACKGROUND

Omalizumab is effective and well-tolerated in children with moderate to severe allergic asthma. However, the effects of long-term treatment with omalizumab in this population haven't been well investigated. The objective of this study is to evaluate the long-term safety, efficacy, pharmacokinetics and pharmacodynamics of omalizumab in children with uncontrolled severe asthma.

METHODS

Thirty-eight Japanese children (aged 7-16 years) who completed the 24-week treatment core study were included in an uncontrolled extension study, in which treatment with omalizumab continued until the pediatric indication was approved in Japan (ClinicalTrials.gov number: NCT01328886).

RESULTS

Thirty-five patients (92.1%) completed the extension study. The median exposure throughout the core and extension studies was 116.6 weeks (range, 46.9-151.1 weeks). The most common adverse events were nasopharyngitis, influenza, upper respiratory tract infection, and asthma. Serious adverse events developed in 10 patients (26.3%), but resolved completely with additional treatments. Incidence of adverse events didn't increase with extended exposure with omalizumab. Twenty-nine patients (76.3%) achieved completely- or well-controlled asthma compared with 9 patients (23.7%) at the start of the extension study. QOL scores, the rates (per year) of hospitalizations and ER visits were significantly improved compared with the baseline of the core study [39.0 vs 48.0 (median), p < 0.001 for QOL, 1.33 vs 0.16, p < 0.001 for hospitalization, 0.68 vs 0.15, p = 0.002 for ER visits]. Remarkably, the mean total IgE level showed a decreasing trend while exposure to omalizumab remained at steady-state.

CONCLUSIONS

Long-term treatment with omalizumab is well-tolerated and effective in children with uncontrolled severe allergic asthma. No new safety findings were identified.

Identification of Asthma Subtypes Using Clustering Methodologies

Asthma is a heterogeneous disease comprising a number of subtypes which may be caused by different pathophysiologic mechanisms (sometimes referred to as endotypes) but may share similar observed characteristics (phenotypes). The use of unsupervised clustering in adult and paediatric populations has identified subtypes of asthma based on observable characteristics such as symptoms, lung function, atopy, eosinophilia, obesity, and age of onset. Here we describe different clustering methods and demonstrate their contributions to our understanding of the spectrum of asthma syndrome. Precise identification of asthma subtypes and their pathophysiological mechanisms may lead to stratification of patients, thus enabling more precise therapeutic and prevention approaches.

Severe asthma features in children: a case-control online survey

Background

Very few studies have explored the distinguishing features of severe asthma in childhood in Europe, and only one study was conducted in Southern Europe. The aim of this study was to provide a detailed characterization of children with severe asthma treated in specialized pediatric asthma centers across Italy.

Methods

We conducted a web-based data collection of family, environmental, clinical and laboratory characteristics of 41 patients aged 6–17 years with severe asthma, defined according to the recent guidelines of the European Respiratory Society and the American Thoracic Society, and 78 age-matched peers with non-severe persistent asthma. The patients have been enrolled from 16 hospital-based pediatric pulmonology and allergy centers in Northern, Central, and Southern Italy. Logistic regression analysis assessed the relationship between patients’ characteristics and severe asthma or non-severe persistent asthma.

Results

Features independently and significantly associated with severe asthma included lifetime sensitization to food allergens [Odds ratio (OR), 4.73; 95 % Confidence Interval (CI), 1.21–18.53; p = 0.03], lifetime hospitalization for asthma (OR, 3.71; 95 % CI, 1.11–12.33; p = 0.03), emergency-department visits for asthma during the past year (OR = 11.98; 95 % CI, 2.70–53.11; p = 0.001), and symptoms triggered by physical activity (OR = 12.78; 95 % CI, 2.66–61.40; p = 0.001). Quality-of-life score was worse in patients with severe asthma than in subjects with non-severe persistent asthma (5.9 versus 6.6, p = 0.005). Self-perception of wellbeing was compromised in more than 40 % of patients in both groups. Children with severe asthma had lower spirometric z scores than non-severe asthmatic peers (all p < 0.001), although 56 % of them had a normal forced expiratory volume in 1 s. No differences were found between the two groups for parental education, home environment, patients’ comorbidities, adherence to therapy, exhaled nitric oxide values, and serum eosinophils and IgE .

Conclusions

As expected, children with severe asthma had more severe clinical course and worse lung function than peers with non-severe persistent asthma. Unlike previous reports, we found greater sensitization to food allergens and similar environmental and personal characteristics in patients with severe asthma compared to those with non-severe persistent asthma. Psychological aspects are compromised in a large number of cases and deserve further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-016-0217-z) contains supplementary material, which is available to authorized users.

Omalizumab in Japanese children with severe allergic asthma uncontrolled with standard therapy

BACKGROUND

Omalizumab has demonstrated clinical benefits in children with moderate to severe allergic asthma. However, no studies have been performed in Japanese asthmatic children. The aim of this study was to evaluate the efficacy including free IgE suppression and safety of omalizumab in Japanese children with severe allergic asthma. The primary objective was to examine whether omalizumab decreases serum free IgE levels to less than 25 ng/ml (target level of suppression).

METHODS

Thirty-eight Japanese children (6-15 years) with uncontrolled severe allergic asthma despite inhaled corticosteroids (>200 μg/day fluticasone propionate or equivalent) and two or more controller therapies received add-on treatment with omalizumab in a 24-week, multicenter, uncontrolled, open-label study.

RESULTS

The geometric mean serum free IgE level at 24 weeks was 15.6 ng/mL. Compared with baseline, total asthma symptom scores, daily activity scores and nocturnal sleep scores at 24 weeks were significantly improved. The rates of asthma exacerbation and hospitalization due to asthma were reduced by 69.2% and 78.2%, respectively (p < 0.001), versus baseline. Quality-of-life scores were also significantly improved (p < 0.001). In addition, 11 (28.9%) patients reduced the dose of any asthma controller medications. Thirty-six (94.7%) patients experienced at least one adverse event during the treatment period. All adverse events were mild or moderate in severity and no new safety concerns were detected. No patients discontinued the study.

CONCLUSIONS

In Japanese children with severe allergic asthma, omalizumab decreased free IgE levels to less than 25 ng/mL. Omalizumab improved asthma control and was well-tolerated, as well.

Update on the current methods for the diagnosis and treatment of severe childhood asthma

The level of asthma control is the key outcome towards which asthma management is evaluated. The majority of children with asthma can obtain adequate control of symptoms through avoidance of triggering factors and/or with the help of low to moderate doses of current available medications. However, there is still a group of children with poor symptom control despite intensive treatment. The current review will provide an overview of a standardized approach to characterize this heterogeneous group of severely sick children. Factors that attenuate the effect of the prescribed treatment and make asthma difficult to treat are discussed. In addition, the usefulness of current methods of assessing asthma severity, pulmonary function, allergy and airway inflammation is also described. Finally, an overview of therapeutic options for children with severe asthma is provided.

The burden of severe asthma in childhood and adolescence: results from the paediatric U-BIOPRED cohorts

U-BIOPRED aims to characterise paediatric and adult severe asthma using conventional and innovative systems biology approaches. A total of 99 school-age children with severe asthma and 81 preschoolers with severe wheeze were compared with 49 school-age children with mild/moderate asthma and 53 preschoolers with mild/moderate wheeze in a cross-sectional study. Despite high-dose treatment, the severe cohorts had more severe exacerbations compared with the mild/moderate ones (annual medians: school-aged 3.0 versus 1.1, preschool 3.9 versus 1.8; p<0.001). Exhaled tobacco exposure was common in the severe wheeze cohort. Almost all participants in each cohort were atopic and had a normal body mass index. Asthma-related quality of life, as assessed by the Paediatric Asthma Quality of Life Questionnaire (PAQLQ) and the Paediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ), was worse in the severe cohorts (mean±se school-age PAQLQ: 4.77±0.15 versus 5.80±0.19; preschool PACQLQ: 4.27±0.18 versus 6.04±0.18; both p≤0.001); however, mild/moderate cohorts also had significant morbidity. Impaired quality of life was associated with poor control and airway obstruction. Otherwise, the severe and mild/moderate cohorts were clinically very similar. Children with severe preschool wheeze or severe asthma are usually atopic and have impaired quality of life that is associated with poor control and airflow limitation: a very different phenotype from adult severe asthma. In-depth phenotyping of these children, integrating clinical data with high-dimensional biomarkers, may help to improve and tailor their clinical management.

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.

Clinical burden and predictors of asthma exacerbations in patients on guideline-based steps 4-6 asthma therapy in the TENOR cohort

BACKGROUND

Patients with severe or difficult-to-treat asthma on guideline-recommended Steps 4/5/6 therapy have not previously been described.

OBJECTIVE

To characterize patients with severe or difficult-to-treat asthma on Steps 4/5/6 therapy and assess predictors of future asthma exacerbations.

METHODS

Patients ages ≥12 years with baseline and month 12 medication data were assigned to Steps 4/5/6 care levels from the 2007 National Heart, Lung, and Blood Institute guidelines. Demographic, atopic, and clinical characteristics at baseline and month 12 were assessed by using descriptive statistics. Asthma-related quality of life was assessed by using the Mini Asthma Quality of Life Questionnaire, and work and activity impairment was assessed by the Work Productivity and Activity Impairment Questionnaire-Asthma. Odds ratios (OR) and 95% CI for asthma exacerbation risk at month 12 were generated by using multivariable logistic regression.

RESULTS

A total of 1186 patients were included. More than two-thirds of the patients (67.4%) were on ≥3 long-term controllers, and 55.1% were considered difficult to treat due to frequent exacerbations. Patients reported low asthma-related quality of life scores and considerable impairment in overall work and daily activity (21.4% and 32.1%, respectively). After adjustment for covariates, exacerbation history (hospitalization, OR 6.27 [95% CI, 3.61-10.88]; emergency department visit, OR 3.84 [95% CI, 2.50-5.91]; corticosteroid burst, OR 2.89 [95% CI, 2.18-3.82]) and very poorly controlled asthma (OR 1.95 [95% CI, 1.41-2.71] vs not well controlled) were independently associated with risk of a future exacerbation (all P < .001).

CONCLUSION

Despite multiple long-term controller medications, patients with severe or difficult-to-treat asthma on Steps 4/5/6 therapy present with significant clinical burden and risk of future asthma exacerbations.

Sleep duration, sleep hygiene, and insomnia in adolescents with asthma

BACKGROUND

There is a need to understand more about modifiable health behaviors that may be related to asthma control. Sleep is one such health behavior that has received little attention in pediatric asthma research.

OBJECTIVE

To examine sleep duration, sleep hygiene, and insomnia in adolescents with and without asthma.

METHODS

Adolescents (n = 298; 51% boys; age range, 12-17 years; 48% with asthma) from the general community completed an online survey that included the International Study of Asthma and Allergies in Childhood questionnaire, the Children's Report of Sleep Patterns, and the Insomnia Severity Index.

RESULTS

Sleep duration did not differ between the asthma severity groups, yet more adolescents with severe asthma reported insufficient weekday sleep (44%) versus adolescents without asthma (31%). Significant asthma group differences were found for sleep hygiene, with adolescents with severe asthma reporting poorer sleep hygiene. Almost twice as many adolescents with severe asthma reported clinically significant insomnia than adolescents with mild or no asthma. Sleep hygiene variables were correlated with insomnia, although these associations did not differ between adolescents with and without severe asthma. Finally, both insomnia severity and asthma severity were significant predictors of daytime sleepiness; however, asthma severity accounted for only 2% of the variance compared with 28% of the variance accounted for by insomnia severity.

CONCLUSIONS

Many adolescents with severe asthma regularly obtain insufficient sleep, have poor sleep hygiene, and experience clinically significant insomnia. It is important to ask adolescents with asthma about sleep duration, sleep hygiene, and insomnia because there are effective interventions that can improve sleep for these youths.

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.

Phenotypes determined by cluster analysis in severe or difficult-to-treat asthma

BACKGROUND

Asthma phenotyping can facilitate understanding of disease pathogenesis and potential targeted therapies.

OBJECTIVE

To further characterize the distinguishing features of phenotypic groups in difficult-to-treat asthma.

METHODS

Children ages 6-11 years (n = 518) and adolescents and adults ages ≥12 years (n = 3612) with severe or difficult-to-treat asthma from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study were evaluated in this post hoc cluster analysis. Analyzed variables included sex, race, atopy, age of asthma onset, smoking (adolescents and adults), passive smoke exposure (children), obesity, and aspirin sensitivity. Cluster analysis used the hierarchical clustering algorithm with the Ward minimum variance method. The results were compared among clusters by χ(2) analysis; variables with significant (P < .05) differences among clusters were considered as distinguishing feature candidates. Associations among clusters and asthma-related health outcomes were assessed in multivariable analyses by adjusting for socioeconomic status, environmental exposures, and intensity of therapy.

RESULTS

Five clusters were identified in each age stratum. Sex, atopic status, and nonwhite race were distinguishing variables in both strata; passive smoke exposure was distinguishing in children and aspirin sensitivity in adolescents and adults. Clusters were not related to outcomes in children, but 2 adult and adolescent clusters distinguished by nonwhite race and aspirin sensitivity manifested poorer quality of life (P < .0001), and the aspirin-sensitive cluster experienced more frequent asthma exacerbations (P < .0001).

CONCLUSION

Distinct phenotypes appear to exist in patients with severe or difficult-to-treat asthma, which is related to outcomes in adolescents and adults but not in children. The study of the therapeutic implications of these phenotypes is warranted.

Assessment of asthma control and asthma exacerbations in the epidemiology and natural history of asthma: outcomes and treatment regimens (TENOR) observational cohort

Patients with severe or difficult-to-treat asthma account for substantial asthma morbidity, mortality, and healthcare burden despite comprising only a small proportion of the total asthma population. TENOR, a multicenter, observational, prospective cohort study was initiated in 2001. It enrolled 4,756 adults, adolescents and children with severe or difficult-to-treat asthma who were followed semi-annually and annually for three years, enabling insight to be gained into this understudied population. A broad range of demographic, clinical, and patient self-reported assessments were completed during the follow-up period. Here, we present key findings from the TENOR registry in relation to asthma control and exacerbations, including the identification of specific subgroups found to be at particularly high-risk. Identification of the factors and subgroups associated with poor asthma control and increased risk of exacerbations can help physicians design individual asthma management, and improve asthma-related health outcomes for these patients.

What is severe asthma?

Asthma is common, and some individuals are severely affected by it. Learned institutions have sought to provide a definition of 'severe asthma' to facilitate research and clinical care. This is a challenging undertaking given the difficulty in defining asthma and the lack of supportive evidence for a distinct severe asthma phenotype. In this review, we discuss the rationale for a definition of severe asthma and the relative merits of the sequential attempts that have been made to produce such a definition. The difficulty in disentangling control and severity is highlighted, as is the heterogeneity of phenotype in severe asthma, and potential for misclassification. We conclude that the search for a singular definition of severe asthma is problematic, though likely to continue. We suggest the alternative strategy of using classifiers with a specific aim related to symptoms, pathophysiology or service provision.

Pathophysiology of asthma: lessons from genetic research with particular focus on severe asthma

There is good evidence that both inherited and environmental factors influence the risk of developing asthma. Only recently, large well-designed studies have been undertaken with the power to identify the genetic causes for asthma, and methods developed in parallel with the Human Genome Project, such as gene expression and epigenetic studies, have made large-scale analyses of functional genetics possible. In this review, we discuss the recent findings from genetic and genomic research studies of asthma, particularly severe asthma, and highlight specific genes for which there are multiple lines of evidence for involvement in asthma pathogenesis. Bio-ontologic enrichment analyses of the most recently identified asthma-related genes point to attributes such as 'molecular and signal transducer activity' and 'immune system processes', which indicates the importance of immunoregulation and inflammatory response in the pathogenesis of asthma. Finally, we discuss how genetic and environmental factors jointly influence asthma susceptibility and summarize how the results may increase understanding of the pathophysiology of asthma-related diseases.

Key findings and clinical implications from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

Patients with severe or difficult-to-treat asthma are an understudied population but account for considerable asthma morbidity, mortality, and costs. The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study was a large, 3-year, multicenter, observational cohort study of 4756 patients (n=3489 adults ≥ 18 years of age, n=497 adolescents 13-17 years of age, and n=770 children 6-12 years of age) with severe or difficult-to-treat asthma. TENOR's primary objective was to characterize the natural history of disease in this cohort. Data assessed semiannually and annually included demographics, medical history, comorbidities, asthma control, asthma-related health care use, medication use, lung function, IgE levels, self-reported asthma triggers, and asthma-related quality of life. We highlight the key findings and clinical implications from more than 25 peer-reviewed TENOR publications. Regardless of age, patients with severe or difficult-to-treat asthma demonstrated high rates of health care use and substantial asthma burden despite receiving multiple long-term controller medications. Recent exacerbation history was the strongest predictor of future asthma exacerbations. Uncontrolled asthma, as defined by the 2007 National Heart, Lung, and Blood Institute guidelines' impairment domain, was highly prevalent and predictive of future asthma exacerbations; this assessment can be used to identify high-risk patients. IgE and allergen sensitization played a role in the majority of severe or difficult-to-treat asthmatic patients.

Severe asthma in childhood: recent advances in phenotyping and pathogenesis

PURPOSE OF REVIEW

Children with severe asthma have a high degree of respiratory morbidity despite treatment with high doses of inhaled corticosteroids and are therefore very difficult to treat. This review will discuss phenotypic and pathogenic aspects of severe asthma in childhood, as well as remaining knowledge gaps.

RECENT FINDINGS

As a group, children with severe asthma have a number of distinct phenotypic features compared with children with mild-to-moderate asthma. Clinically, children with severe asthma are differentiated by greater allergic sensitization, increased exhaled nitric oxide, and significant airflow limitation and air trapping that worsens as a function of age. These findings are accompanied by structural airway changes and increased and dysregulated airway inflammation and oxidant stress which may explain the differential nature of corticosteroid responsiveness in this population. Because children with severe asthma themselves are a heterogeneous group, current efforts are focused on improved definition and sub-phenotyping of the disorder. Whereas the clinical relevance of phenotyping approaches in severe asthma is not yet clear, they may provide important insight into the mechanisms underlying the disorder.

SUMMARY

Improved classification of severe asthma through unified definitions, careful phenotypic analyses, and mechanism-focused endotyping approaches may ultimately advance knowledge and personalized treatment.

IgE antibodies to animal-derived lipocalin, kallikrein and secretoglobin are markers of bronchial inflammation in severe childhood asthma

BACKGROUND

Component-resolved allergy diagnostics enables the detection of crossreactive or species-specific allergen components. This study analysed Immunoglobulin E (IgE) profiles to single allergen components in relation to bronchial inflammation in severe childhood asthma.

METHODS

Ninety-five schoolchildren were assessed, 39 with controlled mild-to-moderate asthma and 56 uncontrolled severe asthmatics. Allergen components (n = 111) of food allergens, pollen and perennial aeroallergens were analysed using an immunosolid-phase allergen chip. Blood eosinophils (10(9) × l(-1)), bronchial inflammation (FeNO, ppb), lung function (FEV(1)%) and bronchial hyper-responsiveness (BHR) (dose-response slope of methacholine challenge) were measured.

RESULTS

A specific IgE response to more than three animal-derived components--lipocalin (nMus m 1, rEqu c 1, Fel d 4, rCan f 1, 2), kallikrein (rCan f 5) and secretoglobin (rFel d 1)--was more common among severe asthmatics compared to children with controlled asthma (n = 14 vs n = 3, P = 0.030). These subjects also displayed higher blood eosinophils (0.65 vs 0.39, P = 0.021), higher Fractional exhaled nitric oxide (38 ppb vs 25 ppb, P = 0.021) and increased BHR (112 vs 28, P = 0.002) compared to other severe asthmatics positive to fewer lipocalin/kallikrein/secretoglobin components. Among all sensitized subjects, there were correlations between specific IgE levels for rFel d 4 and nMus m 1 (r = 0.751, P ≤ 0.001) and for rFel d 4 and rEqu c 1 (r = 0.850, P ≤ 0.001).

CONCLUSION

Multi-sensitization towards lipocalin, kallikrein and secretoglobin components is associated with increased bronchial inflammation in severe asthmatics. In addition, crossreactive patterns were observed between different lipocalin components.

Prescription patterns for asthma medications in children and adolescents with health care insurance in the United States

Asthma is the most common chronic condition of childhood, and its prevalence has increased over recent decades. However, many children and adolescents with asthma are not being managed in accordance with guideline recommendations. The objective of this study was to analyze prescribing patterns for asthma medications in 6- to 18-yr-olds, with a focus on those aged 6-11 yr. Data from patients enrolled for ≥6 months in PharMetrics were analyzed between June 1, 1995, and September 30, 2008. PharMetrics contains data from 45 million US patients from 85 health care plans, including standard and mail order prescription records. Prescriptions for asthma medication for each patient were recorded. The overall asthma cohort included 659,169 patients; 34,950 (5%) were classified as having severe asthma. The 6- to 11-yr-old subgroup consisted of 374,068 patients (56.7% of the overall asthma cohort). Almost 40% of the population received no medication (severe asthma 1.0%; non-severe asthma 37.6%), with almost identical findings in the 6- to 11-yr-old subgroup. In patients with non-severe and severe asthma, frequency of medication use was as follows: short-acting β(2) -agonists (53% and 92%), oral steroids (23% and 64%), leukotriene receptor antagonists (17% and 49%); inhaled corticosteroids alone (15% and 80%) and in combination with long-acting β(2) -agonists (10% and 22%), respectively. Results for patients in the 6- to 11-yr subgroup were similar to those of the overall cohort. In conclusion, a considerable proportion of children and adolescents with asthma do not receive any asthma medication. Among those who do receive medication, adherence to current guidelines is questionable.

Economic burden of impairment in children with severe or difficult-to-treat asthma

BACKGROUND

The cost associated with asthma impairment in children with severe asthma has not been determined.

OBJECTIVE

To assess the asthma cost burden in children with severe or difficult-to-treat asthma based on asthma impairment.

METHODS

Children aged 6 to 12 years in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study with available data at baseline (n = 628), month 12 (n = 385), and month 24 (n = 280) corresponding to the National Heart, Lung, and Blood Institute asthma guidelines' impairment domain were included. Children were categorized as either very poorly controlled (VPC), not well controlled (NWC), or well controlled (WC) and assessed cross-sectionally and longitudinally. Mean total asthma costs based on direct (medication usage, unscheduled office visits, emergency department visits, hospitalizations) and indirect (school/work days lost) asthma costs were assessed.

RESULTS

Mean annual total asthma costs were more than twice as high in the VPC group compared with NWC and WC groups (baseline: $7,846, $3,526, $3,766.44, respectively; month 12: $7,326, $2,959, $2,043, respectively; month 24: $8,879, $3,308, $1,861, respectively (all P < .001). Indirect costs accounted for approximately half the total asthma costs for VPC asthma patients at each time point. Significantly lower costs were observed for patients whose impairment status improved or temporarily improved from VPC after baseline.

CONCLUSION

The economic burden of severe or difficult-to-treat asthma in children is associated with VPC asthma and improvement in asthma control and is associated with reducing cost. Further attention to patients with poorly controlled asthma, through better management strategies or more effective medications, may significantly reduce this burden of illness.

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.

Safety and tolerability of omalizumab in children with allergic (IgE-mediated) asthma

OBJECTIVE

This pooled analysis assessed the safety of omalizumab in children with allergic (immunoglobulin E-mediated) asthma.

STUDY DESIGN

Two double-blind, placebo-controlled studies in children (6 to < 12 years) with moderate-to-severe allergic asthma investigated the efficacy/safety of omalizumab. Children on optimized asthma care (inhaled corticosteroids ± other controller medications) were randomized (2:1) to omalizumab (75-375  mg  sc, q2 or q4 wk) or placebo. Pooled safety findings from these trials are presented in this publication.

RESULTS

The safety population included 926 children (omalizumab, n = 624; placebo, n = 302). Adverse events (AEs) were more frequently reported in the placebo (91.7%) than omalizumab (89.7%) group. The most common AEs were nasopharyngitis, upper respiratory tract infection and headache. Suspected treatment-related AEs included headache, erythema and urticaria; none of which were reported by ≥ 2% of patients receiving omalizumab. Serious AEs (SAEs) were reported by 3.4% and 6.6% of patients receiving omalizumab and placebo, respectively; the most common were appendicitis, pneumonia and bronchitis; no deaths were reported.

CONCLUSIONS

Omalizumab has an acceptable safety profile, with a risk of AEs similar to placebo. This, combined with its efficacy profile, suggests that omalizumab may provide an additional asthma management option for children (6 to < 12 years) uncontrolled with current therapy that follows established guidelines.

Heterogeneity of severe asthma in childhood: confirmation by cluster analysis of children in the National Institutes of Health/National Heart, Lung, and Blood Institute Severe Asthma Research Program

BACKGROUND

Asthma in children is a heterogeneous disorder with many phenotypes. Although unsupervised cluster analysis is a useful tool for identifying phenotypes, it has not been applied to school-age children with persistent asthma across a wide range of severities.

OBJECTIVES

This study determined how children with severe asthma are distributed across a cluster analysis and how well these clusters conform to current definitions of asthma severity.

METHODS

Cluster analysis was applied to 12 continuous and composite variables from 161 children at 5 centers enrolled in the Severe Asthma Research Program.

RESULTS

Four clusters of asthma were identified. Children in cluster 1 (n = 48) had relatively normal lung function and less atopy. Children in cluster 2 (n = 52) had slightly lower lung function, more atopy, and increased symptoms and medication use. Cluster 3 (n = 32) had greater comorbidity, increased bronchial responsiveness, and lower lung function. Cluster 4 (n = 29) had the lowest lung function and the greatest symptoms and medication use. Predictors of cluster assignment were asthma duration, the number of asthma controller medications, and baseline lung function. Children with severe asthma were present in all clusters, and no cluster corresponded to definitions of asthma severity provided in asthma treatment guidelines.

CONCLUSION

Severe asthma in children is highly heterogeneous. Unique phenotypic clusters previously identified in adults can also be identified in children, but with important differences. Larger validation and longitudinal studies are needed to determine the baseline and predictive validity of these phenotypic clusters in the larger clinical setting.

Allergy, total serum immunoglobulin E, and airflow in children and adolescents in TENOR

In children and adolescents with difficult-to-treat asthma, few data exist characterizing the relationships between basic patient characteristics (e.g., age, sex) and atopic indicators in asthma. These associations were examined in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR), an observational study of a large cohort of patients with severe or difficult-to-treat asthma. To characterize allergy patterns and the relationship between total serum immunoglobulin E (IgE) and airflow in young patients with severe or difficult-to-treat asthma. A total of 1261 patients from the TENOR study were stratified into four age groups at baseline (6-8, 9-11, 12-14, and 15-17 yr). The objective was to characterize allergy patterns and the relationship between total serum immunoglobulin E (IgE) and ratio of pre-bronchodilator forced expiratory volume in 1 second to forced vital capacity (FEV(1) /FVC) in young patients with severe or difficult-to-treat asthma. The chi-square test for categorical variables and analysis of variance for continuous variables were used to identify significant differences among age groups. Multivariable linear regression was used to evaluate the association between IgE and FEV(1) /FVC. Allergic rhinitis was reported in approximately two-thirds of patients. Up to 25% of patients had atopic dermatitis, which differed across age groups in boys (p < 0.05). Positive allergen skin test rate differed across age groups in boys (p < 0.05). Rates of asthma triggers were higher and differed across age groups in girls (p < 0.05), particularly around menarche (12-14 yr). IgE levels were higher in boys and differed across age groups in boys (p < 0.01) and girls (p < 0.05). IgE was associated with a lower FEV(1) /FVC after adjusting for age and sex (p < 0.01). Severe or difficult-to-treat asthma in children and adolescents is characterized by high frequencies of comorbid allergic diseases, allergen sensitization, and high IgE levels. This burden is amplified by the association of more airflow limitation with higher IgE levels, suggesting the need for allergy evaluations.

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.

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.