Future of biologics in pediatric asthma: Optimizing response, early introduction, and equitable access to treatment

OBJECTIVE

To evaluate the current evidence, its limitations, and future research directions for the use of biologics in pediatric asthma, with a particular focus on the potential use of biologics to prevent pediatric asthma and equity issues in access to biologic treatment and research participation.

DATA SOURCES

PubMed articles about the use of biologics in pediatric asthma were searched up to May 2023.

STUDY SELECTIONS

Recent (2019-2023) original research articles and reviews were prioritized.

RESULTS

Although there are now 5 U.S. Food and Drug Administration-approved biologics for use in pediatric asthma, there are important knowledge gaps that ongoing research seeks to address, which include (1) the long-term efficacy and safety of using biologics in children, (2) the comparative efficacy of different biologics, (3) multi-omics-based classification of asthma endotypes and phenotypes in children to find potential new therapeutic targets and enable identification and validation of new biomarkers that may predict and help monitor response to treatment, and (4) whether starting biologics in early childhood can modify the natural history of asthma and potentially prevent asthma development.

SUMMARY

To promote equitable access to biologics and optimize asthma outcomes, future research should recruit patients across the full spectrum of socioeconomic and racial/ethnic backgrounds. Large-scale national and international collaborations between asthma researchers and clinicians are also necessary to fully understand the role of biologics in pediatric asthma.

The United Airways Clinic: roadmap of a patient-centred multidisciplinary approach to the complex airways patient: the Sydney model

Severe asthma is a subset of difficult-to-treat asthma which requires a systematic and multidimensional approach including the need to manage multiple comorbidities that mimic asthma. Multidisciplinary care is becoming the standard for the assessment of such patients. Multidisciplinary team (MDT) clinics are virtually nonexistent in the private space. We developed an MDT clinic to handle needs in the private space and found it was an invaluable tool for assessment, reflective practice and professional development.

Trait profiles in difficult-to-treat asthma: Clinical impact and response to systematic assessment

BACKGROUND

Multidisciplinary systematic assessment improves outcomes in difficult-to-treat asthma, but without clear response predictors. Using a treatable-traits framework, we stratified patients by trait profile, examining clinical impact and treatment responsiveness to systematic assessment.

METHODS

We performed latent class analysis using 12 traits on difficult-to-treat asthma patients undergoing systematic assessment at our institution. We examined Asthma Control Questionnaire (ACQ-6) and Asthma Quality of Life Questionnaire (AQLQ) scores, FEV1 , exacerbation frequency, and maintenance oral corticosteroid (mOCS) dose, at baseline and following systematic assessment.

RESULTS

Among 241 patients, two airway-centric profiles were characterized by early-onset with allergic rhinitis (n = 46) and adult onset with eosinophilia/chronic rhinosinusitis (n = 60), respectively, with minimal comorbid or psychosocial traits; three non-airway-centric profiles exhibited either comorbid (obesity, vocal cord dysfunction, dysfunctional breathing) dominance (n = 51), psychosocial (anxiety, depression, smoking, unemployment) dominance (n = 72), or multi-domain impairment (n = 12). Compared to airway-centric profiles, non-airway-centric profiles had worse baseline ACQ-6 (2.7 vs. 2.2, p < .001) and AQLQ (3.8 vs. 4.5, p < .001) scores. Following systematic assessment, the cohort showed overall improvements across all outcomes. However, airway-centric profiles had more FEV1 improvement (5.6% vs. 2.2% predicted, p < .05) while non-airway-centric profiles trended to greater exacerbation reduction (1.7 vs. 1.0, p = .07); mOCS dose reduction was similar (3.1 mg vs. 3.5 mg, p = .782).

CONCLUSION

Distinct trait profiles in difficult-to-treat asthma are associated with different clinical outcomes and treatment responsiveness to systematic assessment. These findings yield clinical and mechanistic insights into difficult-to-treat asthma, offer a conceptual framework to address disease heterogeneity, and highlight areas responsive to targeted intervention.

Regional variation in prevalence of difficult-to-treat asthma and oral corticosteroid use for patients in Australia: heat map analysis

BACKGROUND

In Australia, the regional prevalence of difficult-to-treat asthma is unknown. We aimed to describe regional variation in difficult-to-treat asthma prevalence and oral corticosteroid (OCS) use.

METHODS

In this retrospective, observational, longitudinal study using data from March 2018-February 2019 in the NostraData longitudinal database, prescriptions dispensed for obstructive airway disease were processed through a high-level algorithm to identify patients with asthma. Difficult-to-treat asthma was defined by ≥2 high-dosage inhaled corticosteroids plus long-acting beta-agonist prescriptions over 6 months. Patients who additionally received OCS prescriptions sufficient to treat ≥2 exacerbations over 6 months were classified as having uncontrolled difficult-to-treat asthma. Patient-level data were analyzed across 340 geographic areas in Australia to determine regional prevalence of difficult-to-treat asthma, uncontrolled difficult-to-treat asthma, and OCS use.

RESULTS

Of 1 851 129 people defined as having asthma, 440 800 (24%) were classified as having difficult-to-treat disease. Of those difficult-to-treat asthma patients, 96 338 (22%) were considered to have uncontrolled disease. Between 29% and 48% of patients had difficult-to-treat asthma in 49 geographic areas, most frequently located in Western Australia. Between 26% and 67% of patients had uncontrolled difficult-to-treat asthma in 29 geographic areas (mostly in Eastern Australia). Overall, a wide variability of asthma severity and control was observed among regions.

CONCLUSIONS

Despite global and national guidelines, regional differences in the prevalence of difficult-to-treat asthma and uncontrolled difficult-to-treat asthma and OCS use exist in Australia. Understanding these regional variations should inform policy and target management in the areas with the greatest unmet need.

Workup of difficult-to-treat asthma: implications from treatable traits

Traditional stepwise approach usually adjusts the treatment regimen based on changes in asthma symptoms and severity to achieve good asthma control. However, due to the generalized heterogeneity and complexity of asthma, its therapeutic efficacy in difficult-to-treat asthma is limited. Recently, a precision medicine approach based on the identification and intervention of treatable traits of chronic airway disease has been proposed and appears to be of greater benefit to asthmatics. We reported a 71-year-old male with uncontrolled asthma and multiple exacerbations over the past year. He complained of persistent dyspnea despite high-dose of inhaled corticosteroids plus other controllers. Does this patient have some potential treatable traits contributing to difficult-to-treat asthma? Through a multidimensional assessment of three domains including pulmonary, extrapulmonary, and behavioral/risk factors, 15 treatable traits were identified in the patient, mainly including airflow limitation, eosinophilic airway inflammation, small airway dysfunction, exacerbation prone, dilated cardiomyopathy, diabetes mellitus, inhaler device polypharmacy, smoking, and the absence of an asthma action plan. After targeted treatment for these treatable traits, the patient experienced significant improvement in dyspnea and he could maintain good asthma control with low-dose inhaled corticosteroids and long-acting β₂-agonist. This study shows that, in response to the limitation of a stepwise approach to therapy, treatable traits is a new strategy where patients are individually assessed for a specified set of treatable problems, and an individualized treatment program is developed and implemented based on this multidimensional assessment, especially for difficult-to-treat asthma.

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.

Prevalence and Characterisation of Patients with Asthma According to Disease Severity in Portugal: Findings from the EPI-ASTHMA Pilot Study

Objective

To assess the feasibility of the procedures of EPI-ASTHMA. EPI-ASTHMA is a population-based multicentre stepwise study about the prevalence and characterisation of patients with asthma based on disease severity in Portugal.

Methods

A pilot study of EPI-ASTHMA was conducted with adults from three primary care centres. We followed a stepwise approach comprising 4 stages: stage 0-invitation phone call (n ~1316); stage 1-telephone interview (n ~658); stage 2-clinical assessment with physical examination, diagnostic tests, and patient-reported outcome measures, to confirm the diagnosis of those with possible asthma at stage 1 (n ~160); stage 3-characterization of a subgroup of asthma patients by collecting data through a telephone interview, patient file review and CARATm app (n ~40), after 3-months. The frequency of asthma was calculated in relation to the entire study population (stage 1) and the frequency of difficult-to-treat/severe asthma in relation to the number of asthma patients (stage 3).

Results

From 1305 adults invited, 892 (68%) accepted to participate (stage 0) and 574 (64%; 53[42-67] y; 43% male) were interviewed (stage 1). From those, 148 (26%; 60[46-68] y; 43% male) were assessed at stage 2, and 46 (31%; 51[39-67] y; 44% male) were diagnosed with asthma. Half of these patients (n = 23) accepted to install the app. Stage 3 was completed by 41 (93%) patients, of whom 31 (83%) had asthma confirmed by their file review. A total of 8% of participants had asthma, of those 17% had difficult-to-treat and 5% severe asthma.

Conclusion

Attained recruitment rates and the quality of the results confirmed the feasibility of the EPI-ASTHMA stepwise approach. This pilot study provided insight into the improvement of the procedures to be generalized across the country.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

The Importance of Flexible Bronchoscopy in Difficult-to-treat Asthma from a Pediatric Pulmonology Perspective

OBJECTIVE

Asthma is the most common chronic lung disease in childhood. Difficult-to-treat asthma is defined as the continuation of symptoms or attacks of patients despite step 4 or 5 of Global Initiative for Asthma therapy. In the differential diagnosis of these patients, flexible fiberoptic bronchoscopy is recommended to exclude other lung diseases. In this study, we aimed to examine the clinical and radiologic features and flexible fiberoptic bronchoscopy findings of patients referred to our pediatric pulmonology department due to difficult-to-treat asthma and determine the effects of flexible fiberoptic bronchoscopy on the differential diagnosis and treatment.

MATERIALS AND METHODS

The demographic characteristics and flexible fiberoptic bronchoscopy results of 62 patients who were diagnosed as having difficult-to-treat asthma in our pediatric pulmonology department between January 2015 and June 2020 were evaluated retrospectively. The symptoms, history, medications, physical examination findings, pulmonary function tests, and radiologic findings of patients who underwent flexible fiberoptic bronchoscopy were evaluated.

RESULTS

The median age of the patients was 69 (interquartile range: 42-108 months). The most common reasons for the referral of these patients were chronic cough, recurrent pulmonary infections, and persistent wheezing. All patients had chest radiography and 37 (59.7%) had chest computed tomography at their first admission; 14 (37.8%) patients had abnormal findings on chest computed tomography. There was no significant difference in terms of age, physical examination findings, pulmonary function test results, and radiologic examinations between patients with and without pathologic bronchoscopy findings. None of the patients had complications during and after flexible fiberoptic bronchoscopy. The most common diagnoses of patients based on flexible fiberoptic bronchoscopy were persistent bacterial bronchitis in 19 (30.6%) patients, tracheomalacia and/or bronchomalacia in 12 (19.4%), and anatomic anomalies in 3 (4.8%) patients (separation of lingula into 3, separation of right upper lobe bronchus into 4, and tracheal dyskinesia). Mycobacterium tuberculosis growth was observed in the tuberculosis culture of 1 patient. According to the flexible fiberoptic bronchoscopy and bronchoalveolar lavage results, antituberculosis treatment was initiated in 1 patient and polypoid mass excision was performed in 1 patient. A proton pump inhibitor was started in 9 (15.5%) patients, physiotherapy in 5 (8.0%), antibiotics in 14 (22.5%), and ipratropium bromide in 7 (11.2%) patients. All patients were followed up with the diagnosis of asthma except for 2 patients.

CONCLUSION

To date, there is no prospective study evaluating the importance of flexible fiberoptic bronchoscopy in difficult-to-treat asthma in childhood. In our small cohort, persistent bacterial bronchitis, airway tracheomalacia and/or bronchomalacia, gastroesophageal reflux, and other anatomic anomalies were successfully diagnosed using flexible fiberoptic bronchoscopy and treated without any complications, suggesting that flexible fiberoptic bronchoscopy is an important diagnostic tool with a low complication rate in children with difficult-to-treat asthma.

Voice bubbling therapy for vocal cord dysfunction in difficult-to-treat asthma - a pilot study

OBJECTIVE

Dysfunctional breathing often coexists with asthma and complicates asthma control, especially in difficult-to-treat asthma. Voice bubbling therapy (VBT) by a specialized speech therapist may influence the breathing pattern. This pilot study investigated the effect of voice bubbling therapy (VBT) in participants with difficult-to-treat asthma, who fulfilled criteria for dysfunctional breathing pattern.

METHOD

Twenty-four patients were randomized between VBT and usual care (UC). VBT is blowing into a glass (resonance) tube (28 cm in length, 0.9 cm inner diameter) which ends in a bowl of water (1.5 litre). Lung function, capillary blood gas and questionnaires were measured at baseline, at 6 and 18 weeks of follow up.

RESULTS

No difference in ACQ and quality of life was found after VBT compared to UC group. However, after six weeks of bubbling therapy, pCO2 levels measured in capillary blood gas were higher (baseline median (IQR) pCO2 = 33.00 (17.25 - 38.6) mmHg; week 6 pCO2 = 36.00 (29.00 - 42.3) mmHg) p = 0.01. Moreover, ΔpCO2 (baseline - 18 weeks of follow up) was significantly correlated with ΔAQLQ (rs = 0.78, p = 0.02).

CONCLUSION

VBT in participants with difficult-to-treat asthma resulted in a higher average pCO2 level, indicating the treatment may improve hyperventilation. However, this did not improve asthma control or quality of life. VBT may have value for a better management of asthma related symptoms.

Health-Related Effects of Home Nebulization With Glycopyrronium on Difficult-to-Treat Asthma: Post-Hoc Analyses of an Observational Study

BACKGROUND

Bronchial asthma remains a clinical enigma with poorly controlled symptoms or exacerbations despite regular use of inhaled corticosteroids. Home nebulization offers a simplified solution for the delivery of rescue and maintenance bronchodilators, which is especially true for patients with frequent exacerbations during management of uncontrolled or difficult-to-treat asthma.

OBJECTIVE

We aimed to assess the clinical impact and outcomes associated with home nebulization-delivered long-acting bronchodilators for uncontrolled or difficult-to-treat asthma.

METHODS

This observational, concurrent study was conducted with 60 patients at 2 centers during November 2018. Statistical analyses for prebronchodilator forced expiratory volume in one second (FEV1) and Global Initiative for Asthma (GINA) asthma control score in patients on long-acting bronchodilators and corticosteroids were conducted, with two-tailed P values <.05 considered statistically significant.

RESULTS

Per protocol analyses (53/60) for consecutive cases receiving home nebulization with long-acting bronchodilators and corticosteroids were conducted. The baseline demographics included a male-to-female ratio of 30:23 and mean values of the following: age, 60.3 years (SD 11.8 years); weight, 64 kg (SD 16.8 kg); FEV1, 43% (SD 16%); GINA asthma control score, 3.0 points (SD 0.8 points); serum eosinophil level, 4% (SD 3%); fractional exhaled nitric oxide (FeNO), 12.1 ppb (SD 6 ppb). Of the patients, 100% (53/53) had uncontrolled symptoms, 69.8% (37/53) had prior exacerbations, 100% (53/53) used formoterol/budesonide, and 75.5% (40/53) used glycopyrronium. The per protocol group (n=53) had significantly improved mean prebronchodilator FEV1 (23.7%, SD 29.8%; 0.46 L, SD 0.58 L; P<.001) and GINA asthma control score (2.1 points, SD 0.8 points, P<.001). At baseline, patients (n=40) receiving glycopyrronium/formoterol/budesonide (25/20/500 mcg) nebulization admixture had the following mean values: prebronchodilator FEV1, 38% (SD 15%); GINA asthma control score, 3.0 points (SD 0.8 points); reversibility, 12% (SD 6%); peripheral eosinophil level, 4% (SD 3%); FeNO, 12 ppb (SD 5.7 ppb). In the post hoc analyses, these patients had significantly improved mean prebronchodilator FEV1 of 27.7% (SD 26.2%; 0.54 L, SD 0.51 L; P<.001) at 8 weeks compared with baseline. At baseline, patients (n=13) receiving formoterol/budesonide (20/500 mcg) nebulization had the following mean values: FEV1, 55% (SD 12%); GINA asthma control score, 3.0 points (SD 1.2 points); reversibility, 14% (SD 7%); serum eosinophil level, 4% (SD 3%); FeNO, 13.3 ppb (SD 6.8 ppb). In the post hoc analyses, these patients showed a significant improvement in prebronchodilator FEV1 of 11.2% (SD 13.1%; 0.22 L, SD 0.25 L; P<.001) from baseline. Breathlessness of mild to moderate intensity was reported by 10 cases (10/53, 18.9%), with no other treatment-emergent adverse events or serious adverse events.

CONCLUSIONS

Home nebulization remains a viable option for symptomatic difficult-to-treat asthma cases with frequent use of rescue medications. Glycopyrronium as add-on therapy offers a synergistic response in patients on corticosteroids with difficult-to-treat asthma.

TRIAL REGISTRATION

Clinical Trial Registry of India CTRI/2018/11/016319; https://tinyurl.com/y78cctm3.

Pediatric use of omalizumab for allergic asthma

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Screening for the Most Common Mutations of CFTR Gene among Egyptian Children with Difficult-to-Treat Asthma

Cystic fibrosis (CF) is panethnic autosomal recessive disease that affects the exocrine glands of pancreas, lungs, and intestine. It is often misdiagnosed in developing countries as difficult-to-treat asthma. We enrolled 150 Egyptian families with one or more probands who were complaining of difficult-to-treat asthma, and 112 cases were studied extensively through history taking including pedigree construction and clinical examination. In addition, spirometry and computed tomography of the chest were done in selected cases. All cases were subjected to quantitative sweat chloride test and molecular screening for the three most common mutations of cystic fibrosis transconductance regulator ( CFTR ) gene ( ΔF508 , G542X , W1282X ) using amplification refractory mutation system (ARMS) technique. Probands of difficult-to-treat asthma comprised 66 males and 46 females; their age range was 1 to 14 years. Sixty-one probands (54.5%) were carriers of one or more of the studied mutations (36 cases and 25 carriers). Six carriers of single mutations had mild respiratory symptoms and negative sweat test. The most common allele was ΔF508 , 60 alleles in 56 individuals (4 were homozygous ΔF508 / ΔF508 ) followed by W1282X in 25 individuals and G542X in 12 individuals. Allele W1282X had an increased risk of recurrent chest infection and bronchiectasis. Moreover, cases with two mutations had more severe symptoms compared with those with a single mutation. CFTR mutations and CF-related syndromes are not rare as thought in Egypt, especially among the high-risk difficult-to-treat asthma. The readily available ARMS technique is recommended for ΔF508 and/or W1282X screening on priority basis among these children.

[A Difficult-to-Treat Asthma Bronchiale Is Not Necessarily a Severe Asthma]

A Difficult-to-Treat Asthma Bronchiale Is Not Necessarily a Severe Asthma Abstract. New biologicals offer the opportunity for treatment of 'difficult-to-treat' asthma. Before prescribing these medications, each 'difficult-to-treat' asthma bronchiale has to be checked for factors aggravating asthma control (e.g. insufficient inhalation technique and adherence, persistent allergen exposure) and asthma-related comorbidities (e.g. rhinosinusitis, gastro-esophageal reflux disease or obstructive sleep apnea) rendering the asthma 'controlled'. Asthma phenotyping s essential for the understanding of different treatment modalities.

A Practical Approach to Severe Asthma in Children

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

Polish Society of Allergology statement on the diagnosis and treatment of severe, difficult-to-control bronchial asthma

Severe asthma requires at least high doses of inhaled corticosteroids (ICS) in combination with a long-acting β-agonist (LABA) or systemic corticosteroids (SCS) for more than 50% of days/year to avoid loss of control, or remains uncontrolled despite the treatment described above. The diagnosis of severe asthma should be confirmed in a reference centre as it requires careful differential diagnosis and the exclusion of factors hindering the achievement of optimal control. Severe asthma represents a significant burden for the patient, their family and the healthcare system. This is due to the severity of the symptoms, drug costs, significant impairment of everyday functioning and life quality, and limitation in the professional work. In the case of ineffectiveness of the step 4 GINA treatment, the patient should be referred to a specialist centre to consider additional treatment, including anti-IgE receptor (omalizumab), anti-IL-5 receptor (mepolizumab), or an antibody directed against the α-subunit of receptor for IL-5 (benralizumab). In the case of severe asthma, intensification of therapy should first of all include biological therapy and not the use of SCS. Biological drugs are available in Poland as a part of the therapeutic programme for the treatment of severe asthma. In practice, the therapeutic programme may change with subsequent notices of the Ministry of Health and does not have to be consistent with the Summary of Product Characteristics for individual preparations. The current review presents the basic principles of differential diagnosis of severe asthma and the selection of the optimal biological therapy in Polish conditions.

Severe Asthma and Allergy: A Pediatric Perspective

Severe asthma in children is associated with significant morbidity and lung function decline. It represents a highly heterogeneous disorder with multiple clinical phenotypes. As its management is demanding, the social and economic burden are impressive. Several co-morbidities may contribute to worsen asthma control and complicate diagnostic and therapeutic management of severe asthmatic patients. Allergen sensitization and/or allergy symptoms may predict asthma onset and severity. A better framing of "allergen sensitization" and understanding of mechanisms underlying progression of atopic march could improve the management and the long-term outcomes of pediatric severe asthma. This review focuses on the current knowledge about interactions between severe asthma and allergies.

Clinical management of severe therapy-resistant asthma

INTRODUCTION

Severe therapy-resistant asthma is an area where there has been recent advances in understanding that is percolating into improvements in management. Areas covered: This review covers the recent definition and approach to the diagnosis of severe asthma and its differentiation from difficult-to-treat asthma. The recent advances in phenotyping severe asthma and in ensuing changes in management approaches together with the introduction of new therapies are covered from a review of the recent literature. Expert commentary: After ascertaining the diagnosis of severe asthma, patients need to be treated adequately with existing therapies. The management approach to severe asthma now comprises of a phenotyping step for the definition of either an allergic or eosinophilic severe asthma for which targeted therapies are currently available. This will lead to a precision medicine approach to the management of severe asthma.

Factors leading to refractory asthma in patients from Saudi Arabia

AIM:

The aim of this study was to study the clinical characteristic of patient with refractory asthma (RA) from Saudi Arabia.

METHODS:

This paper prospectively studied in a university hospital factors leading to RA in a cohort of patients who have inadequately controlled asthma or with frequent exacerbations despite optimum controller therapy. It also studied patients with asthma that requires extended periods of oral steroids to control.

RESULTS:

The mean age was 45.1 years (±9.1) where 74 patients were enrolled in this study with the age group (37–48 years) is having the highest percentage (64.8%). Female patients represented 62.2%. The two major comorbid conditions were allergic rhinitis (54.1%) and gastroesophageal reflux (33.8%). The vast majority (72 patients) had at least one trigger factor for asthma (97.3%). The asthma control test showed that 86.4% had an uncontrolled status. Spirometry showed mild disease in 9.5%, moderate in 47.3%, and severe in 43.2%. Eosinophilia was seen in only 16.2%. Immunoglobulin E level between 70 and 700 μg/L was found in 58.1% of patients.

CONCLUSION:

RA has certain clinical characteristics and associated comorbid conditions as well as precipitating factors that facilitate the identifications of these cases.

Phenotypes of severe asthma among children and adolescents in Brazil: a prospective study

BACKGROUND

The morbidity associated with severe uncontrolled asthma is disproportionately higher in low- and middle-income countries than in high-income countries. The aim of this study was to describe the phenotypic characteristics of difficult-to-treat severe asthma and treatment-resistant severe asthma in a sample of children and adolescents in Brazil.

METHODS

This was a prospective study, conducted between 2010 and 2014, following 61 patients (6-18 years of age) who had been diagnosed with severe uncontrolled asthma. The patients were classified and managed in accordance with the World Health Organization asthma follow-up protocol, which calls for re-evaluations of the diagnosis, level of control (functional and clinical), comorbidities, inhaler technique, and environmental factors, together with adjustment of the treatment to achieve a target level of control. We assessed pulmonary function, measured fractional exhaled nitric oxide, and performed sputum cytology. After the target rate of ≥ 80% adherence to inhaled corticosteroid treatment had been reached and all of the re-evaluations had been performed, the patients incorrectly diagnosed with severe uncontrolled asthma were excluded and the remaining patients were classified as having treatment-resistant or difficult-to-treat severe asthma.

RESULTS

We found that, of the 61 patients evaluated, 10 had been misdiagnosed (i.e., they did not have asthma), 15 had moderate asthma, and 36 had severe uncontrolled asthma. Among those 36 patients, the asthma was classified as treatment-resistant in 20 (55.6%) and as difficult-to-treat in 16 (44.4%). In comparison with the patients with difficult-to-treat severe asthma, those with treatment-resistant severe asthma showed a higher median level of fractional exhaled nitric oxide (40 ppb vs. 12 ppb; P < 0.037) and a lower median forced expiratory volume in one second (61% vs. 87%; P < 0.001).

CONCLUSIONS

Although patients with treatment-resistant severe asthma cannot always be distinguished from those with difficult-to-treat severe asthma on the basis of baseline clinical characteristics, reduced airflow and elevated fractional exhaled nitric oxide are factors that could distinguish the two groups. Patients diagnosed with severe uncontrolled asthma should be re-evaluated on a regular basis, in order to exclude other diagnoses, to reduce exacerbations, and to identify patients with persistent airflow limitation.

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.

Vocal cord dysfunction diagnosed by four-dimensional dynamic volume computed tomography in patients with difficult-to-treat asthma: A case series

Patients with asthma may also have vocal cord dysfunction (VCD), which leads to poor control of the asthma. Once patients are diagnosed with difficult-to-treat asthma with poor control, VCD should be excluded or treated accordingly. The gold standard for diagnosis of VCD is to perform a laryngoscopy. However, this procedure is invasive and may not be suitable for patients with difficult-to-treat asthma. Four-dimensional (4D) dynamic volume computed tomography (CT) is a noninvasive method for quantification of laryngeal movement, and can serve as an alternative for the diagnosis of VCD. Herein, we present a series of five cases with difficult-to-treat asthma patients who were diagnosed with VCD by 4D dynamic volume CT. Clinicians should be alert to the possibility of VCD when poor control is noted in patients with asthma. Early diagnosis by noninvasive 4D dynamic volume CT can decrease excessive doses of inhaled corticosteroids.

Two cases of tracheal disease misdiagnosed as difficult-to-treat asthma

Initial management of patients with difficult-to-treat asthma must begin with confirmation of the diagnosis. We present 2 cases of tracheal disease misdiagnosed as difficult-to-treat asthma. After systemic evaluation, tracheomalacia and tracheobronchial narrowing due to diffuse calcification of the cartilaginous rings were found as mimicking asthma.

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.