Difficult-to-control asthma: epidemiology and its link with environmental factors

A Comprehensive Look at the Development of Asthma in Children

Asthma, a prevalent chronic respiratory condition affecting millions of children globally, presents a significant health challenge. This review critically examines the developmental pathways of asthma in children, focusing on genetic, environmental, and early-life determinants. Specifically, we explore the impact of prenatal and postnatal factors such as maternal smoking, nutrition, respiratory infections, and allergen exposure on asthma development. Our analysis highlights the intricate interplay of these influences and their contribution to childhood asthma. Moreover, we emphasize targeted strategies and interventions to mitigate its burden, including genetic counseling for at-risk families, environmental modifications to reduce triggers, and early-life immunomodulation. By delving into these preventive measures and interventions, our review aims to provide actionable insights for healthcare professionals in developing tailored strategies to address the complexities of childhood asthma. In summary, this article offers a detailed examination of asthma development in children, aiming to enhance understanding and inform efforts to reduce its burden through targeted interventions.

Smoking, Urban Housing and Work-Aggravated Asthma are Associated with Asthma Severity in a Cross-Sectional Observational Study

Purpose

Severe asthma affects 5 to 10% of asthmatics and accounts for a large part of asthma-related morbidity and costs. The determinants of asthma severity are poorly understood. We tested the hypothesis that asthma severity was associated with 1) atopy and allergy and 2) markers associated with environmental exposure.

Patients and Methods

Data from the FASE-CPHG study, a cross-sectional, observational, multicenter investigation, were analyzed to identify markers associated with asthma severity. Asthma severity was gauged using the ASSESS score, encompassing symptom control, exacerbations, FEV1 and therapeutic load. Bivariate and multivariate analyses were used to identify patient characteristics associated with the ASSESS score.

Results

The analysis involved 948 patients, with 592 women, of which 447 patients (47%) had severe asthma. Among these, 491 patients (52%) had at least one positive aeroallergen skin prick test and 525 (55%) had at least one allergic disease among atopic dermatitis, chronic rhinitis and food allergy. The mean±SD ASSESS score was 11.2±3.4. Characteristics associated with a higher ASSESS score were female sex, secondary or lower education, unemployed occupational status, smoking, work-aggravated asthma and urban housing. There was no association between the ASSESS score and allergic diseases, aeroallergen-specific skin prick tests and IgEs, or blood eosinophil counts.

Conclusion

While atopy and allergy were frequent among asthmatics, neither was associated with asthma severity. Modifiable environmental factors such as smoking, urban housing and work-aggravated asthma were independently associated with asthma severity.

Assessment and management of anxiety and depression in a pediatric high-risk asthma clinic

OBJECTIVE

The aims of this study were to determine the prevalence of positive mental health (MH) screens in a pediatric high-risk asthma (HRA) clinic population, and to determine the success rate of engagement in MH services before and after adding a clinical psychologist to our multidisciplinary clinic.

HYPOTHESIS

We hypothesized that the HRA population would have a higher prevalence of anxiety/depression symptoms than that previously reported for the general pediatric asthma population. We anticipated that the presence of an embedded psychologist in HRA clinic would facilitate successful connection to MH services.

METHODS

Pediatric patients in the HRA clinic were prospectively screened for anxiety and depression using validated screening instruments. Positive scores were referred for MH services. Time to MH service engagement was recorded before and after the addition of a clinical psychologist.

RESULTS

A total of 186 patients were screened; 60% had a positive MH screen. Female sex was associated with higher median scores on both screening tools and higher likelihood of engagement in MH services. After addition of a clinical psychologist, new engagement in MH services increased (20% vs. 80%, p < 0.0001), and median time to engagement decreased (14.5 vs. 0.0 months, p = 0.003).

CONCLUSION

There is a high prevalence of anxiety and depression in this pediatric HRA population. Success of engagement in MH services improved after a clinical psychologist joined our multidisciplinary team, suggesting access to care as a primary barrier to engagement.

Environmental allergen reduction in asthma management: an overview

Asthma is a prevalent non-communicable disease that affects both children and adults. Many patients with severe, uncontrolled asthma could not achieve total control despite using anti-asthmatic drugs. There is increasing evidence that allergy to environmental allergens, including both indoor and outdoor allergens, is associated with asthma symptoms and severe asthma. Frequently reported sensitized allergens were dust mites, cockroaches, grass pollens, molds, pets, and rodents in allergic asthma patients, although the patterns of widespread allergens differed from each country. Allergen avoidance is the cornerstone of asthma management, especially in sensitized subjects. This review summarizes environmental allergen avoidance and clarifies their effects on asthma control. Despite contrasting results about the impact of allergen exposure reduction on asthma control, several studies supported the beneficial effects of reducing asthma-related symptoms or risk of exacerbations as a nondrug therapy. Identifying environmental allergens is helpful for asthma patients, and further studies on clinically effective avoidance methods are required.

Type-2 CD8+ T-cell formation relies on interleukin-33 and is linked to asthma exacerbations

CD4+ T helper 2 (Th2) cells and group 2 innate lymphoid cells are considered the main producers of type-2 cytokines that fuel chronic airway inflammation in allergic asthma. However, CD8+ cytotoxic T (Tc) cells - critical for anti-viral defense - can also produce type-2 cytokines (referred to as 'Tc2' cells). The role of Tc cells in asthma and virus-induced disease exacerbations remains poorly understood, including which micro-environmental signals and cell types promote Tc2 cell formation. Here we show increased circulating Tc2 cell abundance in severe asthma patients, reaching peak levels during exacerbations and likely emerging from canonical IFNγ+ Tc cells through plasticity. Tc2 cell abundance is associated with increased disease burden, higher exacerbations rates and steroid insensitivity. Mouse models of asthma recapitulate the human disease by showing extensive type-2 skewing of lung Tc cells, which is controlled by conventional type-1 dendritic cells and IFNγ. Importantly, we demonstrate that the alarmin interleukin-33 (IL-33) critically promotes type-2 cytokine production by lung Tc cells in experimental allergic airway inflammation. Our data identify Tc cells as major producers of type-2 cytokines in severe asthma and during exacerbations that are remarkably sensitive to alterations in their inflammatory tissue micro-environment, with IL-33 emerging as an important regulator of Tc2 formation.

Relationships between the Content of Micro- and Macroelements in Animal Samples and Diseases of Different Etiologies

Many of the micro- and macro-elements (MMEs) required by the body are found in environmental objects in concentrations different from their original concentration that can lead to dangerous animal diseases ("microelementoses"). The aim was to study the features of MME (accumulating in wild and exotic animals) in connection with particular diseases. The work using 67 mammal species from four Russian zoological institutions was completed in 2022. Studies of 820 cleaned and defatted samples (hair, fur, etc.) after "wet-acid-ashing" on an electric stove and in a muffle furnace were performed using a Kvant-2A atomic absorption spectrometer. The content of zinc, copper, iron, cadmium, lead, and arsenic was assessed. The level of MME accumulation in the animal body contributes not only to the MME status and the development of various concomitant diseases, but the condition itself can occur by intake of a number of micronutrients and/or drugs. Particular correlations between the accumulation of Zn and skin, oncological diseases, Cu-musculoskeletal, cardiovascular diseases, Fe-oncological diseases, Pb-metabolic, nervous, oncological diseases, and Cd-cardiovascular diseases were established. Therefore, monitoring of the MME status of the organism must be carried out regularly (optimally once every 6 months).

Uncontrolled Asthma Among Children and Its Association With Parents’ Asthma Knowledge and Other Socioeconomic and Environmental Factors

Objective To estimate the frequency of uncontrolled asthma among asthmatic children from Jeddah and to analyze its association with parental asthma knowledge and other socioeconomic and environmental factors. Method A cross-sectional study was conducted at the Pediatrics Departments of King Abdulaziz University Hospital (KAUH) in Jeddah, Saudi Arabia, from July to December 2018. It involved the caregivers of 150 children with asthma, who were following at KAUH. A structured questionnaire was administered by a phone interview to collect the following: socioeconomic and environmental factors of asthma, answers to the Arabic version of the Asthma Control Test^TM (ACT), and answers to the Arabic version of the caregiver Asthma Knowledge questionnaire (AKq). Result The frequency of uncontrolled asthma was 32.7% (95%CI: 25.2 - 40.8). Parents had myths about asthma such as "children with asthma should use asthma control medications (inhaled corticosteroids) only when they have symptoms" and "it's not good for children to use the inhaler for too long". Besides, we observed mixed results regarding parents' knowledge about the disease, with correct answers ranging from 56.0% to 88.7% depending on the item. Exposure to bakhoor (aromatic woodchips) at home (OR = 0.41, p=0.044), two or more ICU admissions during the past 12 months (OR = 3.30, p=0.030), and using a rescue inhaler even if there's no cough or wheeze when the child gets the flu (OR = 0.22, p=0.001) were the three independent factors of uncontrolled asthma among children. Conclusion Uncontrolled asthma concerns one-third of the asthmatic children following at our centre, representing a less concerning figure compared to the national data. The contribution of parents' knowledge to asthma control did not show significant results, although uncontrolled asthma may represent an opportunity to increase parents' knowledge and awareness. We emphasize the significance of exposure to bakhoor, the use of oral steroids, and the number of ICU admission as strong indicators for uncontrolled asthma in children. An adaptive national strategy should be designed to enable effective and personalized interventions, resources, and objectives for maximized benefits.

Physical training in adults with asthma: An integrative approach on strategies, mechanisms, and benefits

Asthma is a chronic airway disease characterized by airflow limitation and respiratory symptoms associated with chronic airway and systemic inflammation, bronchial hyperreactivity (BHR), and exercise-induced bronchoconstriction (EIB). Asthma is a heterogeneous disease classified according to distinct airway and systemic inflammation. Patients commonly present with several comorbidities, including anxiety, depression, poor sleep quality, and reduced physical activity levels. Individuals with moderate to severe asthma often have more symptoms and difficulty achieving adequate clinical control, which is associated with poor quality of life, despite proper pharmacological treatment. Physical training has been proposed as an adjunctive therapy for asthma. Initially, it was suggested that the effect of physical training might be attributed to the improved oxidative capacity and reduced production of exercise metabolites. However, in the last decade, there has been evidence that aerobic physical training promotes anti-inflammatory effects in asthma patients. Physical training improves BHR and EIB, asthma symptoms, clinical control, anxiety, and depression levels, sleep quality, lung function, exercise capacity, and dyspnea perception. Furthermore, physical training reduces medication consumption. The most commonly used exercise strategies are moderate aerobic and breathing exercises; however, other techniques, such as high-intensity interval training, have shown promising effects. In the present study, we reviewed the strategies and beneficial effects of exercise on clinical and pathophysiological asthma outcomes.

The combined effect of exposures to vapours, gases, dusts, fumes and tobacco smoke on current asthma

Smoking, exposure to environmental tobacco smoke (ETS) and occupational exposure to vapours, gases, dusts or fumes (VGDF) increase asthma symptoms. The impact of combined exposure is less well established. We aimed to evaluate the risk of combined exposure to smoking, ETS and VGDF on the prevalence of current asthma and asthma-related symptoms with a postal survey among a random population of 16,000 adults, aged 20-69 years (response rate 51.5%). The 836 responders with physician-diagnosed asthma were included in the analysis. Of them, 81.9% had current asthma defined as physician-diagnosed asthma with current asthma medication use or reported symptoms. There was a consistently increasing trend in the prevalence of current asthma by increased exposure. The highest prevalence of multiple symptoms was in smokers with VGDF exposure (92.1%) compared to the unexposed (73.9%, p = 0.001). In logistic regression analysis, combined exposure to several exposures increased the risk in all analysed symptoms (p = 0.002-0.007). In conclusion, smoking and exposure to ETS or VGDF increased the prevalence of current asthma and multiple symptoms. The combined exposure carried the highest risk. Preventive strategies are called for to mitigate exposure to tobacco smoke and VGDF.

Association of mold levels in urban children's homes with difficult-to-control asthma

BACKGROUND

Mold sensitization and exposure are associated with asthma severity, but the specific species that contribute to difficult-to-control (DTC) asthma are unknown.

OBJECTIVE

We sought to determine the association between overall and specific mold levels in the homes of urban children and DTC asthma.

METHODS

The Asthma Phenotypes in the Inner-City study recruited participants, aged 6 to 17 years, from 8 US cities and classified each participant as having either DTC asthma or easy-to-control (ETC) asthma on the basis of treatment step level. Dust samples had been collected in each participant's home (n = 485), and any dust remaining (n = 265 samples), after other analyses, was frozen at -20^oC. The dust samples (n = 265) were analyzed using quantitative PCR to determine the concentrations of the 36 molds in the Environmental Relative Moldiness Index. Logistic regression was performed to discriminate specific mold content of dust from homes of children with DTC versus ETC asthma.

RESULTS

Frozen-dust samples were available from 54% of homes of children with DTC (139 of 253) and ETC asthma (126 of 232). Only the average concentration of the mold Mucor was significantly (P < .001) greater in homes of children with DTC asthma. In homes with window air-conditioning units, the Mucor concentration contributed about a 22% increase (1.6 odds ratio; 95% CI, 1.2-2.2) in the ability to discriminate between cases of DTC and ETC asthma.

CONCLUSIONS

Mucor levels in the homes of urban youth were a predictor of DTC asthma, and these higher Mucor levels were more likely in homes with a window air-conditioner.

Asthma Management System in Primary Care Based on Global Initiative for Asthma and Snell's Drug Interaction: Accuracy and Usability

Background

The two main pillars of asthma management include regular follow-up and using guidelines in the treatment process. Patient portals enable regular follow-up of disease, and guideline-based decision-support-systems can improve the use of guidelines in the treatment process. Based on the Global Initiative for Asthma (GINA) and Snell's drug interaction, asthma management system in primary care (AMSPC) includes the capabilities of both mentioned systems. This system was developed to improve regular follow-up and use GINA in the asthma management process. This study aimed to assess the accuracy and usability of the AMSPC based on the GINA and Snell's drug interaction.

Materials and Methods

To assess the accuracy of the system, kappa test was used to calculate the degree of agreement between the suggestions made by the system and the physician's decision for a total of 64 patients selected through convenience sampling method. To assess usability, the Questionnaire for User Interface Satisfaction (QUIS) was used.

Results

The scores of the Kappa for the agreements between the system and the physician in determining "drug type and dosage", "follow-up time", and "drug interactions" were 0.90, 0.94, and 0.94, respectively. The average score of the QUIS was 8.6 out of 9.

Conclusion

Due to the high accuracy of the system in computerizing the GINA and Snell's drug interaction, as well as its proper usability, it is expected that the system be widely used to improve asthma management and reduce drug interactions.

2021 Brazilian Thoracic Association recommendations for the management of severe asthma

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

Nicotinic α7 acetylcholine receptor (α7nAChR) in human airway smooth muscle

Diseases such as asthma are exacerbated by inflammation, cigarette smoke and even nicotine delivery devices such as e-cigarettes. However, there is currently little information on how nicotine affects airways, particularly in humans, and changes in the context of inflammation or asthma. Here, a longstanding assumption is that airway smooth muscle (ASM) that is key to bronchoconstriction has muscarinic receptors while nicotinic receptors (nAChRs) are only on airway neurons. In this study, we tested the hypothesis that human ASM expresses α7nAChR and explored its profile in inflammation and asthma using ASM of non-asthmatics vs. mild-moderate asthmatics. mRNA and western analysis showed the α7 subunit is most expressed in ASM cells and further increased in asthmatics and smokers, or by exposure to nicotine, cigarette smoke or pro-inflammatory cytokines TNFα and IL-13. In these effects, signaling pathways relevant to asthma such as NFκB, AP-1 and CREB are involved. These novel data demonstrate the expression of α7nAChR in human ASM and suggest their potential role in asthma pathophysiology in the context of nicotine exposure.

Sojadodamgangki-tang attenuates allergic lung inflammation by inhibiting T helper 2 cells and Augmenting alveolar macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Sojadodamgangki-tang (SDG) is a traditional East-Asian herbal medicine mainly composed of Pinellia ternate (Thunb.) Makino, Perilla frutescens (L.) Britt and 10 kinds of medicinal herbs. It has been used to treat asthma and mucus secretion including lung and bronchi.

AIM OF THE STUDY

The aim of this study was to investigate the anti-inflammatory effects of Sojadodamgangki-tang (SDG) on allergic lung inflammation in vitro and in vivo as well as the underlying mechanisms.

MATERIALS AND METHODS

We used an ovalbumin (OVA)-induced murine allergic airway inflammation model. Five groups of 8-week-old female BALB/C mice were divided into the following groups: saline control group, the vehicle (allergic) group that received OVA only, groups that received OVA and SDG (200 mg/kg or 400 mg/kg), and a positive control group that received OVA and Dexamethasone (5 mg/kg). In vitro experiments include T helper 2 (TH2) polarization system, murine macrophage cell culture, and human bronchial epithelial cell line (BEAS-2B) culture.

RESULTS

SDG administration reduced allergic airway inflammatory cell infiltration, especially of eosinophils, mucus production, Th2 cell activation, OVA-specific immunoglobulin E (IgE), and total IgE production. Moreover, the activation of alveolar macrophages, which leads to immune tolerance in the steady state, was promoted by SDG treatment. Interestingly, SDG treatment also reduced the production of alarmin cytokines by the human bronchial epithelial cell line BEAS-2B stimulated with urban particulate matter.

CONCLUSION

Our findings indicate that SDG has potential as a therapeutic drug to inhibit Th2 cell activation and promote alveolar macrophage activation.

Linkage of Maternal Caregiver Smoking Behaviors on Environmental and Clinical Outcomes of Children with Asthma: A Post-Hoc Analysis of a Financial Incentive Trial Targeting Reduction in Pediatric Tobacco Smoke Exposures

(1) Background: Monthly variability in smoking behaviors in caregivers of pediatric asthmatics yields questions of how much and when does smoking reduction result in improved environmental and clinical outcomes. (2) Methods: Post hoc analysis of data from a 6 month pilot randomized-control trial occurring from May 2017 to May 2018 in Baltimore City (MD, USA). The initial trial's primary intervention explored the utility of financial incentives in modifying caregiver smoking behaviors. Post hoc analyses examined all dyads independent of the initial trial's randomization status. All caregivers received pediatric tobacco smoke harm reduction education, in addition to monthly encouragement to access the state tobacco quitline for individual phone-based counseling and nicotine replacement therapy. Maternal caregivers who were active cigarette smokers and their linked asthmatic child (aged 2-12 years) were grouped into two classifications ("high" versus "low") based on the child and caregiver's cotinine levels. A "low" cotinine level was designated by at least a 25% reduction in cotinine levels during 3 months of the trial period; achieving ≤2 months of low cotinine levels defaulted to the "high" category. Twenty-seven dyads (caregivers and children) (total n = 54) were assigned to the "high" category, and eighteen dyads (caregivers and children) (total n = 36) were allocated to the "low" category. The primary outcome measure was the correlation of caregiver cotinine levels with pediatric cotinine values. Secondary outcomes included asthma control, in addition to caregiver anxiety and depression. (3) Results: Caregivers with 3 months of ≥25% decrease in cotinine levels had a significantly greater mean change in child cotinine levels (p = 0.018). "Low" caregiver cotinine levels did not significantly improve pediatric asthma control (OR 2.12 (95% CI: 0.62-7.25)). Caregiver anxiety and depression outcomes, measured by Patient Health Questionnaire (PHQ)-4 scores, was not significantly different based on cotinine categorization (p = 0.079); (4) Conclusion: Reduced pediatric cotinine levels were seen in caregivers who reduced their smoking for at least 3 months, but clinical outcome measures remained unchanged.

Probiotics function and modulation of the immune system in allergic diseases

Allergic diseases have been a global problem over the past few decades. The effect of allergic diseases on healthcare systems and society is generally remarkable and is considered as one of the most common causes of chronic and hospitalized disease. The functional ability of probiotics to modulate the innate/acquired immune system leads to the initiation of mucosal/systemic immune responses. Gut microbiota plays a beneficial role in food digestion, development of the immune system, control/growth of the intestinal epithelial cells and their differentiation. Prescribing probiotics causes a significant change in the intestinal microflora and modulates cytokine secretion, including networks of genes, TLRs, signaling molecules and increased intestinal IgA responses. The modulation of the Th1/Th2 balance is done by probiotics, which suppress Th2 responses with shifts to Th1 and thereby prevent allergies. In general, probiotics are associated with a decrease in inflammation by increasing butyrate production and induction of tolerance with an increase in the ratio of cytokines such as IL-4, IL-10/IFN-γ, Treg/TGF-β, reducing serum eosinophil levels and the expression of metalloproteinase-9 which contribute to the improvement of the allergic disease's symptoms. Finally, it can be said that the therapeutic approach to immunotherapy and the reduction of the risk of side effects in the treatment of allergic diseases is the first priority of treatment and the final approach that completes the first priority in maintaining the condition and sustainability of the tolerance along with the recovery of the individual.

Medical Neglect as a Contributor to Poorly Controlled Asthma in Childhood

Child maltreatment, including medical neglect, is a frequent contributor to the development of asthma as well as a barrier to its proper management. This article aims to review the role of medical neglect as a contributor to poor asthma control. Medical neglect can present as failure of the caretaker to recognize severe asthma symptoms in a child, non-adherence to medical management, failure to prevent chronic exposure to allergens or tobacco smoke, poor child nutrition leading to obesity, and allowing a young child to manage his/her illness without supervision. This article will explore the different factors leading to medical neglect (as illustrated by two cases) and suggest possible interventions aiming to prevent emergency department visits, hospitalizations, and asthma-related deaths.

Asthma and Obesity in Children

Asthma and obesity are two major chronic diseases in children and adolescents. Recent scientific evidence points out a causative role of obesity in asthma predisposition. However, studies assessing the real impact of excessive weight gain on lung function in children have shown heterogeneous results. In this review, the pathological mechanisms linking obesity and development of asthma in children are summarized and factors influencing this relationship are evaluated. Common disease modifying factors including age, sex, ethnicity, development of atopic conditions, and metabolic alterations significantly affect the onset and phenotypic characteristics of asthma. Given this, the impact of these several factors on the obesity–asthma link were considered, and from revision of the literature we suggest the possibility to define three main clinical subtypes on the basis of epidemiological data and physiological–molecular pathways: obese-asthmatic and atopy, obese-asthmatic and insulin-resistance, and obese-asthmatic and dyslipidemia. The hypothesis of the different clinical subtypes characterizing a unique phenotype might have an important impact for both future clinical management and research priorities. This might imply the necessity to study the obese asthmatic child with a “multidisciplinary approach”, evaluating the endocrinological and pneumological aspects simultaneously. This different approach might also make it possible to intervene earlier in a specific manner, possibly with a personalized and tailored treatment. Surely this hypothesis needs longitudinal and well-conducted future studies to be validated.

Bronchial Thermoplasty

Bronchial thermoplasty is an advanced therapy for severe asthma. It is a bronchoscopic procedure in which radiofrequency energy is applied to the airway wall, resulting in decreased airway smooth muscle burden. Human trials have shown that bronchial thermoplasty may reduce asthma exacerbations and improve quality of life in patients with severe uncontrolled asthma. It has been demonstrated to be a safe procedure, with most adverse events being early and mild. More studies are required to understand the precise effects of bronchial thermoplasty on the asthmatic airway and optimal parameters to appropriately select patients for this novel procedure.

Treatment Adherence in Young Children with Asthma

Treatment nonadherence in young children with asthma involves multiple factors and should be viewed within an ecological framework. Few interventions have targeted multiple bidirectional factors, however, and little research has examined which interventions may be most appropriate for young children. Additional research is needed to identify essential intervention components, and to determine how to sustain such interventions in at-risk communities. Pediatric psychologists, with training in psychosocial intervention, screening, and primary prevention models, may be uniquely equipped to partner with communities and medical settings to develop and sustain targeted interventions for young children with asthma.

BAL Cell Gene Expression in Severe Asthma Reveals Mechanisms of Severe Disease and Influences of Medications

Rationale: Gene expression of BAL cells, which samples the cellular milieu within the lower respiratory tract, has not been well studied in severe asthma.Objectives: To identify new biomolecular mechanisms underlying severe asthma by an unbiased, detailed interrogation of global gene expression.Methods: BAL cell expression was profiled in 154 asthma and control subjects. Of these participants, 100 had accompanying airway epithelial cell gene expression. BAL cell expression profiles were related to participant (age, sex, race, and medication) and sample traits (cell proportions), and then severity-related gene expression determined by correlating transcripts and coexpression networks to lung function, emergency department visits or hospitalizations in the last year, medication use, and quality-of-life scores.Measurements and Main Results: Age, sex, race, cell proportions, and medications strongly influenced BAL cell gene expression, but leading severity-related genes could be determined by carefully identifying and accounting for these influences. A BAL cell expression network enriched for cAMP signaling components most differentiated subjects with severe asthma from other subjects. Subsequently, an in vitro cellular model showed this phenomenon was likely caused by a robust upregulation in cAMP-related expression in nonsevere and β-agonist-naive subjects given a β-agonist before cell collection. Interestingly, ELISAs performed on BAL lysates showed protein levels may partly disagree with expression changes.Conclusions: Gene expression in BAL cells is influenced by factors seldomly considered. Notably, β-agonist exposure likely had a strong and immediate impact on cellular gene expression, which may not translate to important disease mechanisms or necessarily match protein levels. Leading severity-related genes were discovered in an unbiased, system-wide analysis, revealing new targets that map to asthma susceptibility loci.

Economic Impact and Clinical Outcomes of Omalizumab Add-On Therapy for Patients with Severe Persistent Asthma: A Real-World Study

BACKGROUND

Omalizumab is a fully humanized monoclonal antibody indicated as add-on therapy to improve asthma control in patients with severe persistent allergic asthma.

AIMS

The aim of this study was to evaluate social, healthcare expenditure and clinical outcomes changes after incorporating omalizumab into standard treatment in the control of severe asthma.

METHODS

In this multicentre retrospective study, a total of 220 patients were included from 15 respiratory medicine departments in the regions of Andalusia and Extremadura (Spain). Effectiveness was calculated as a 3-point increase in the Asthma Control Test (ACT) and a reduction in the annual number of exacerbations. The economic evaluation included both direct and indirect costs. Incremental cost-effectiveness ratio (ICER) was calculated. Results from the year before and the year after incorporation of omalizumab were compared.

RESULTS

After adding omalizumab, improvement of lung function, asthma and rhinitis according to patient perception, as well as the number of exacerbations and asthma control measured by the ACT score were observed. Globally, both healthcare resources and pharmacological costs decreased after omalizumab treatment, excluding omalizumab cost. When only direct costs were considered, the ICER was €1712 (95% CI 1487-1995) per avoided exacerbation and €3859 (95% CI 3327-4418) for every 3-point increase in the ACT score. When both direct and indirect costs were considered, the ICER was €1607 (95% CI 1385-1885) for every avoided exacerbation and €3555 (95% CI 3012-4125) for every 3-point increase.

CONCLUSIONS

Omalizumab was shown to be an effective add-on therapy for patients with persistent severe asthma and allowed reducing key drivers of asthma-related costs.

Dual exposure to smoking and household air pollution is associated with an increased risk of severe asthma in adults in Brazil

Background

The relationship between smoking, household pollution, dual exposure and severity of asthma in adults has not been sufficiently studied. We examined and compared the effects of cigarette smoking, domestic wood burning pollution and dual exposure (tobacco and wood burning) upon asthma severity in adults.

Methods

This was a cross-sectional study performed with 452 individuals with mild to moderate asthma and 544 patients with severe asthma (previously untreated). Smoking and exposure to wood smoke were identified and quantified through questionnaires to evaluate current and/or previous exposure; objective determination of cigarette exposure was obtained through the measurement of urinary cotinine. Asthma control was evaluated through Asthma Control Questionnaire; and severity was classified according to the Global Initiative for Asthma criteria. Subjects were grouped according to exposure type into 4 groups: smokers, household pollution, dual-exposure and no-exposure. Chi square, Mann-Whitney, and Kruskal-Wallis tests were used for comparisons between groups.

Results

Out of 996 included individuals, 78 (7.8%) were exposed to cigarette smoking alone, 358 (35.9%) to household pollution alone, 155 (15.6%) to the two exposures combined and 405 (40.7%) were not exposed. Compared to unexposed individuals, exposure to household pollution resulted in poorer asthma control, higher proportion of severe asthma, and worse indicators of lung function. The double-exposed individuals were worse off in all the evaluated parameters, and they were significantly worse than subjects with single exposure to household air pollution in relation to asthma severity and lung function. These subjects were predominantly females, older, with longer residence time in rural areas, lower income and lower schooling levels. Multivariate analysis showed that exposure to household pollution and double exposure were predictive factors associated with lack of control and increased severity of asthma.

Conclusions

Exposure to household pollution is associated with poorer control, greater severity, and poorer pulmonary function; double-exposed individuals have a greater risk of severe asthma and decreased lung function than those exposed only to household pollution.

Does allergy explain why some children have severe asthma?

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

Development and Validation of Personalized Prediction to Estimate Future Risk of Severe Exacerbations and Uncontrolled Asthma in Patients with Asthma, Using Clinical Parameters and Early Treatment Response

BACKGROUND

Current level of asthma control can be easily assessed by validated instruments, but it is currently difficult to assess individuals' level of future risk.

OBJECTIVE

Develop, and validate, a risk prediction score for level of future risk, including patient characteristics and information on early treatment response.

METHODS

We used data of 304 adult patients with asthma from a 12-month primary care randomized controlled trial with 3-monthly assessments. With logistic regression we modeled the association between the level of future risk and patient characteristics including early treatment response. Future risk was defined as Asthma Control Questionnaire (ACQ) score of 1.5 or more at 12 months or the experience of at least 1 exacerbation during the final 6 months. We developed a risk prediction score on the basis of regression coefficients.

RESULTS

Performance of the risk prediction score improved, taking into account data on early treatment response (area under receiver-operating curve [AUROC] = 0.84) compared with a model containing only baseline characteristics (AUROC = 0.78). The score includes 6 easy-to-obtain predictors: sex, ACQ score and exacerbations in the previous year at baseline and at first follow-up, and smoking status and exacerbations in the previous 3 months (indicating early treatment response). External validation yielded an AUROC of 0.77. The risk prediction score classified patients into 3 risk groups: low (absolute risk, 11.7%), intermediate (47.0%), and high (72.7%).

CONCLUSIONS

We developed and externally validated a risk prediction score, quantifying both level of current asthma control and the guideline-defined future risk. Patients' individual risk can now be estimated in an easy way, as proposed but not specified, by asthma management guidelines.

TGF-β1 Evokes Human Airway Smooth Muscle Cell Shortening and Hyperresponsiveness via Smad3

Transforming growth factor β1 (TGF-β1), a cytokine whose levels are elevated in the airways of patients with asthma, perpetuates airway inflammation and modulates airway structural cell remodeling. However, the role of TGF-β1 in excessive airway narrowing in asthma, or airway hyperresponsiveness (AHR), remains unclear. In this study, we set out to investigate the direct effects of TGF-β1 on human airway smooth muscle (HASM) cell shortening and hyperresponsiveness. The dynamics of AHR and single-cell excitation-contraction coupling were measured in human precision-cut lung slices and in isolated HASM cells using supravital microscopy and magnetic twisting cytometry, respectively. In human precision-cut lung slices, overnight treatment with TGF-β1 significantly augmented basal and carbachol-induced bronchoconstriction. In isolated HASM cells, TGF-β1 increased basal and methacholine-induced cytoskeletal stiffness in a dose- and time-dependent manner. TGF-β1-induced single-cell contraction was corroborated by concomitant increases in myosin light chain and myosin phosphatase target subunit 1 phosphorylation levels, which were attenuated by small interfering RNA-mediated knockdown of Smad3 and pharmacological inhibition of Rho kinase. Strikingly, these physiological effects of TGF-β1 occurred through a RhoA-independent mechanism, with little effect on HASM cell [Ca2+]i levels. Together, our data suggest that TGF-β1 enhances HASM excitation-contraction coupling pathways to induce HASM cell shortening and hyperresponsiveness. These findings reveal a potential link between airway injury-repair responses and bronchial hyperreactivity in asthma, and define TGF-β1 signaling as a potential target to reduce AHR in asthma.

The characteristic of asthma control among nasal diseases population: Results from a cross-sectional study

Asthma affects a large number of patients in China, but comprehensive evaluation of risks associated with poor asthma control in asthmatic patients with nasal diseases was still limited. We conducted this study to provide a comprehensive estimate of asthma control in Chinese asthma patients with combined nasal diseases, to explore the effect of kinds of nasal diseases on the asthma control, and to identify risk factors associated with uncontrolled asthmatic patients with combined nasal diseases. 1756 asthma patients concomitant with nasal diseases aged ≥17 years and representing all regions of mainland China were surveyed. Multivariate logistic regression model with all related demographic characteristics and disease characteristics factors entered was used to identify risk factors associated with uncontrolled asthma. 56.4% of asthmatic patients with combined allergic rhinitis or rhinosinusitis or rhinopolyp remained uncontrolled. Concomitant without allergic rhinitis, younger age, better treatment adherence and higher education level might positively impact asthma control among asthmatic patients with combined nasal diseases. Perennial allergic rhinitis (OR = 1.5, P = 0.021), moderate-severe allergic rhinitis (OR = 2.2, P = 0.001) were all found to significantly increase the risk of uncontrolled asthma among asthma patients with combined allergic rhinitis. The high prevalence of uncontrolled asthma indicates that asthma management among adult Chinese asthmatic patients comorbid with nasal disease is still a challenge. Efforts should be made to raise the awareness of asthma management and to provide sufficient treatment will greatly contribute to improved quality of asthma management. It is possible to minimize the influence of allergic rhinitis on asthma control by improving nasal function, especially for more severe allergic rhinitis and perennial allergic rhinitis.

Psychological and lifestyle risk factors for asthma exacerbations and morbidity in children

Asthma is the most common childhood illness and disproportionately affects low-income, minority children who live in urban areas. A range of risk factors are associated with asthma morbidity and mortality, such as treatment non-adherence, exposure to environmental triggers, low-income households, exposure to chronic stress, child psychological problems, parental stress, family functioning, obesity, physical inactivity, and unhealthy diets. These risk factors often have complex interactions and inter-relationships. Comprehensive studies that explore the inter-relationships of these factors in accounting for asthma morbidity and mortality are needed and would help to inform clinical intervention. Considerable research has focused on interventions to improve adherence, asthma management, asthma symptoms, and quality of life for patients with asthma. Educational interventions combined with psychosocial interventions, such as behavioral, cognitive-behavioral, or family interventions, are beneficial and provide care in schools, homes, and emergency rooms can help to address barriers to accessing care for children and families. Additional recent research has explored the use of multidisciplinary, collaborative, integrated care with pediatric asthma patients, providing promising results. Integrated care could be ideal for addressing the multitude of complex psychosocial and wellness factors that play a role in childhood asthma, for increasing patient-centered care, and for promoting collaborative patient-provider relationships. Further research in this area is essential and would be beneficial.

High prevalence of severe asthma in a large random population study

BACKGROUND

The prevalence of asthma severity is not well described at a population level.

OBJECTIVE

We sought to determine the prevalence of phenotypic signs of asthma severity among asthmatic patients in a general population and to describe risk factors for asthma severity.

METHODS

We performed an epidemiologic study conducted between 2008 and 2012 (West Sweden Asthma Study). A postal questionnaire was sent to a random population (n = 30,000) in west Sweden, with 18,087 responses. A total of 2,006 subjects were carefully phenotyped. Only subjects with "active asthma" (symptoms or medication in the last year, n = 744) were analyzed in this study to determine the degree of severity of the disease within an asthma cohort. Phenotypes of severity were calculated based on (1) multiple symptoms during the day despite ongoing use of asthma medications, (2) FEV₁ of less than 70% of predicted value, (3) daily or almost daily use of rescue medications, (4) nighttime symptoms once a week or more, and (5) oral corticosteroid use/emergency department visits. Asthmatic patients were grouped as having nonsevere disease, 1 sign of severity, or 2 or more signs of severity.

RESULTS

A total of 36.2% of asthmatic patients expressed at least 1 sign of asthma severity, and 13.2% had 2 or more signs. The group with 2 or more signs was older in age and had higher body mass index, a higher rate of tobacco smoking, and lower lung function. Bronchial hyperreactivity, airway inflammation, and sensitization were significantly different among the 3 groups. At a population level, the prevalence of asthma severity was 3.1% for 1 sign and 1.3% for at least 2 signs.

CONCLUSION

More than 1 in 3 asthmatic patients show at least 1 sign of asthma severity. The phenotypes of asthma severity are highly diverse, which is important to consider when implementing personalized medicine in asthmatic patients.

The association between environmental tobacco smoke exposure and childhood respiratory disease: a review

INTRODUCTION

Childhood respiratory illness is a major cause of morbidity and mortality particularly in low and middle-income countries. Environmental tobacco smoke (ETS) exposure is a recognised risk factor for both acute and chronic respiratory illness. Areas covered: The aim of this paper was to review the epidemiology of ETS exposure and impact on respiratory health in children. We conducted a search of 3 electronic databases of publications on ETS and childhood respiratory illness from 1990-2015. Key findings were that up to 70% of children are exposed to ETS globally, but under-reporting may mask the true prevalence. Maternal smoking and ETS exposure influence infant lung development and are associated with childhood upper and lower respiratory tract infection, wheezing or asthma. Further, exposure to ETS is associated with more severe respiratory disease. ETS exposure reduces lung function early in life, establishing an increased lifelong risk of poor lung health. Expert commentary: Urgent and effective strategies are needed to decrease ETS exposure in young children to improve child and long-term lung health in adults especially in low and middle income countries where ETS exposure is increasing.

Allergic risks of consuming edible insects: A systematic review

The expected future demand for food and animal-derived protein will require environment-friendly novel food sources with high nutritional value. Insects may be one of such novel food sources. However, there needs to be an assessment of the risks associated with their consumption, including allergic risks. Therefore, we performed a systematic review aiming to analyse current data available regarding the allergic risks of consuming insects. We reviewed all reported cases of food allergy to insects, and studied the possibility of cross-reactivity and co-sensitisation between edible insects, crustaceans and house dust mites. We analysed a total of 25 articles - eight assessing the cross-reactivity/co-sensitisation between edible insects, crustaceans and house dust mites; three characterizing allergens in edible insects and 14 case reports, describing case series or prevalence studies of food allergy caused by insects. Cross-reactivity/co-sensitisation between edible insects and crustaceans seems to be clinically relevant, while it is still unknown if co-sensitisation between house dust mites and edible insects can lead to a food allergy. Additionally, more information is also needed about the molecular mechanisms underlying food allergy to insects, although current data suggest that an important role is played by arthropod pan-allergens such as tropomyosin or arginine kinase.

Severe Asthma in Children

PURPOSE OF REVIEW

The aim of this study is to characterize, diagnose, evaluate, and treat severe childhood asthma.

RECENT FINDINGS

Understanding the occurrence of the physiologic and clinical presentations of childhood severe asthma, the treatment and response may be predicted by biomarkers, but the patient's response is highly variable. The onset of severe asthma occurs early and is primarily predicted by severity of viral infection and coexistence of the atopic state.

Endotypes of difficult-to-control asthma in inner-city African American children

African Americans have higher rates of asthma prevalence, morbidity, and mortality in comparison with other racial groups. We sought to characterize endotypes of childhood asthma severity in African American patients in an inner-city pediatric asthma population. Baseline blood neutrophils, blood eosinophils, and 38 serum cytokine levels were measured in a sample of 235 asthmatic children (6-17 years) enrolled in the NIAID (National Institute of Allergy and Infectious Diseases)-sponsored Asthma Phenotypes in the Inner City (APIC) study (ICAC (Inner City Asthma Consortium)-19). Cytokines were quantified using a MILLIPLEX panel and analyzed on a Luminex analyzer. Patients were classified as Easy-to-Control or Difficult-to-Control based on the required dose of controller medications over one year of prospective management. A multivariate variable selection procedure was used to select cytokines associated with Difficult-to-Control versus Easy-to-Control asthma, adjusting for age, sex, blood eosinophils, and blood neutrophils. In inner-city African American children, 12 cytokines were significant predictors of Difficult-to-Control asthma (n = 235). CXCL-1, IL-5, IL-8, and IL-17A were positively associated with Difficult-to-Control asthma, while IL-4 and IL-13 were positively associated with Easy-to-Control asthma. Using likelihood ratio testing, it was observed that in addition to blood eosinophils and neutrophils, serum cytokines improved the fit of the model. In an inner-city pediatric population, serum cytokines significantly contributed to the definition of Difficult-to-Control asthma endotypes in African American children. Mixed responses characterized by TH2 (IL-5) and TH17-associated cytokines were associated with Difficult-to-Control asthma. Collectively, these data may contribute to risk stratification of Difficult-to-Control asthma in the African American population.

New Insights into Cockroach Allergens

PURPOSE OF REVIEW

This review addresses the most recent developments on cockroach allergen research in relation to allergic diseases, especially asthma.

RECENT FINDINGS

The number of allergens relevant to cockroach allergy has recently expanded considerably up to 12 groups. New X-ray crystal structures of allergens from groups 1, 2, and 5 revealed interesting features with implications for allergen standardization, sensitization, diagnosis, and therapy. Cockroach allergy is strongly associated with asthma particularly among children and young adults living in inner-city environments, posing challenges for disease control. Environmental interventions targeted at reducing cockroach allergen exposure have provided conflicting results. Immunotherapy may be a way to modify the natural history of cockroach allergy and decrease symptoms and asthma severity among sensitized and exposed individuals. The new information on cockroach allergens is important for the assessment of allergen markers of exposure and disease, and for the design of immunotherapy trials.

Is allergic sensitization relevant in severe asthma? Which allergens may be culprit?

Severe asthma is a major health concern. The allergic (IgE-mediated) form of asthma is well known from a pathogenic viewpoint. We searched the available literature to identify which allergens are most frequently associated with severe, refractory or life threatening asthma. According to the results, molds, pet dander, cockroach and ragweed were more frequently responsible for severe asthma. Thunderstorm asthma, in addition, represents a special association between allergic sensitization and an external climatic factor. A detailed knowledge of the most harmful allergens is mandatory for an appropriate diagnostic and preventive approach.

Uncontrolled asthma and its risk factors in adult Chinese asthma patients

Background:

Asthma affects a large number of patients in China, but relatively little is known about asthma management among Chinese patients. This study aims to estimate asthma control rate among adult Chinese patients and to identify predictors associated with uncontrolled asthma.

Methods:

A total of 4125 asthma patients aged ⩾17 years and representing all regions of mainland China except Tibet were surveyed. Asthma control status was assessed using the Asthma Control Test (ACT) and classified as controlled (ACT score ⩾ 20) and uncontrolled (ACT score ⩽ 19). A multivariate logistic regression model was used to identify predictors associated with uncontrolled asthma from the factors including demographics, rhinitis, allergic rhinitis, and treatment adherence.

Results:

Asthma was controlled in 44.9%, and uncontrolled in 55.1% of the study participants. High rates of uncontrolled asthma were found in patients with treatment nonadherence (77.3%), poor adherence (66.2%), no schooling (64.8%), or obesity (62.9%). The risk of uncontrolled asthma was much higher in the treatment nonadherence group than the complete adherence group [odds ratio (OR) = 4.55 (3.68–5.62), p < 0.001]. Other predictors for uncontrolled asthma included concomitant rhinitis [OR = 1.31 (1.14–1.50), p < 0.001], obesity [OR = 1.31 (1.05–1.64), p = 0.019], asthma duration > 3 years [OR = 1.22 (1.07–1.39), p = 0.004] and age ⩾ 45 years [OR = 1.23 (1.07–1.41), p = 0.004].

Conclusions:

About half of the participants in this study had uncontrolled asthma. Treatment nonadherence is one of the significant predictors, which is very strongly associated with uncontrolled asthma. Efforts should be prioritized to promote patients’ treatment adherence to improve asthma control while attention is needed on rhinitis or obesity.

Epidemiology and Pulmonary Physiology of Severe Asthma

The epidemiology and physiology of severe asthma are inherently linked because of varying phenotypes and expressions of asthma throughout the population. To understand how to better treat severe asthma, we must use both population data and physiologic principles to individualize therapies among groups with similar expressions of this disease.

Novel genetic risk factors for asthma in African American children: Precision Medicine and the SAGE II Study

Asthma, an inflammatory disorder of the airways, is the most common chronic disease of children worldwide. There are significant racial/ethnic disparities in asthma prevalence, morbidity, and mortality among US children. This trend is mirrored in obesity, which may share genetic and environmental risk factors with asthma. The majority of asthma biomedical research has been performed in populations of European decent. We sought to identify genetic risk factors for asthma in African American children. We also assessed the generalizability of genetic variants associated with asthma in European and Asian populations to African American children. Our study population consisted of 1227 (812 asthma cases, 415 controls) African American children with genome-wide single nucleotide polymorphism (SNP) data. Logistic regression was used to identify associations between SNP genotype and asthma status. We identified a novel variant in the PTCHD3 gene that is significantly associated with asthma (rs660498, p = 2.2 × 10(-7)) independent of obesity status. Approximately 5 % of previously reported asthma genetic associations identified in European populations replicated in African Americans. Our identification of novel variants associated with asthma in African American children, coupled with our inability to replicate the majority of findings reported in European Americans, underscores the necessity for including diverse populations in biomedical studies of asthma.