Inflammatory and Comorbid Features of Patients with Severe Asthma and Frequent Exacerbations

Delayed kinetics of phagocytosis related respiratory burst in blood is a distinctive feature of moderate exacerbation of bronchial asthma

Atopic bronchial asthma based on allergy history and chronic inflammation is hazardous to patients due to the risk of exacerbation. The sign of severe exacerbation is considered an abundant number and high activity of granulocytes in respiratory system and blood. Relationships between the ability of cells in blood to produce reactive radicals and their metabolites and the severity of asthma remain largely unclear. Kinetics of respiratory burst evoked by microbe particles in blood samples of patients was studied to reveal the most significant predictors distinguishing states of moderate exacerbation and out of exacerbation. Asthmatic patients with exacerbation (n = 18) or out of exacerbation (n = 62) and healthy individuals (n = 43) were characterized on respiratory function, cell count in blood and kinetics of generation of reactive radicals and their metabolites during phagocytosis. Mean values of respiratory parameters forced expiratory volume in 1 s and peak expiratory flow rate in patients with exacerbation were significantly differed compared with same of patients out of exacerbation and healthy individuals. Mean values of cell count in blood did not significantly differed in patients with exacerbation and out of exacerbation. Receiver operating characteristic analysis showed that both cell count and respiratory indexes did not discriminate patients with exacerbation from out of exacerbation. A delayed response to opsonized zymosan was revealed in patients with exacerbation compared to other examinees: lengthened lag-time and T_max, reduced production of reactive species. T_max was the most statistically significant predictor to discriminate bronchial asthma exacerbation from bronchial asthma out of exacerbation (area under curve >90%, p < 10^-5) and controls (area under curve >80%, p < 10^-5). Thus kinetic parameters of the phagocyte response to opsonized zymosan in the whole blood are the best predictors of bronchial asthma exacerbation in comparison with respiratory parameters and blood cell count. This test can be used for immunological monitoring of bronchial asthma status to prevent exacerbation.

Severe asthma in children: Evaluation and management

Severe asthma in children is associated with significant morbidity. Children with severe asthma are at increased risk for adverse outcomes including medication-related side effects, life-threatening exacerbations, and impaired quality of life. It is important to differentiate between severe therapy resistant asthma and difficult-to-treat asthma due to comorbidities. The most common problems that need to be excluded before a diagnosis of severe asthma can be made are poor medication adherence, poor medication technique or incorrect diagnosis of asthma. Difficult to treat asthma is a much more common reason for persistent symptoms and exacerbations and can be managed if comorbidities are clearly addressed. Children with persistent symptoms and exacerbations despite correct inhaler technique and good medical adherence to standard Step 4 asthma therapies according to the guidelines^1,2, should be referred to an asthma specialist with expertise in severe asthma.

Variability in total serum IgE over 1 year in severe asthmatics

Background

Immunoglobulin E (IgE) is the treatment target of omalizumab, a monoclonal antibody indicated in the treatment of severe allergic asthma. Long-term variability of serum total IgE (sIgE_tot) in asthmatics remains poorly documented.

Methods

In this prospective study, sIgE_tot levels were measured over 1 year at 7 time points in 41 severe asthmatics treated with high-dose of inhaled corticosteroids and long-acting β₂ agonists. 33 patients were atopic based on at least one positive RAST to common aeroallergens. Patients were divided into three groups according to their baseline sIgE_tot level: low (< 76 IU/mL; n = 10), intermediate (76-700 IU/mL; n = 20) or high (> 700 IU/mL; n = 11). Patients also completed the six-item Juniper Asthma Control Questionnaire (ACQ₆). The sIgE_tot variability and factors predictive for this variability were studied, as well as ACQ₆ outcomes.

Results

The variation in sIgE_tot level was mostly the consequence of between patient-variability, which represented 96%, 71% and 96% of the total variability in the low, intermediate and high sIgE_tot subgroups, respectively. The residual within-patient variability was therefore limited. In 10/41 patients, sIgE_tot levels increased or decreased, for at least one visit, beyond the predefined range of the subgroups to which they were assigned (< 76 IU/mL; 76-700 IU/mL; > 700 IU/mL). There was a significant but weak correlation between sIgE_tot and ACQ₆ score over all time points (r = 0.15, p = 0.02), but sIgE_tot failed to associate with severe exacerbation. sIgE_tot decreased by 3% with any additional year of age for the whole group (p = 0.01) and increased by 5% per one unit of allergen exposure score in atopic patients (p = 0.002).

Conclusion

In severe asthmatics, limited within-patient variability of sIgE_tot levels was observed over 1 year as opposed to marked between-subject variability. sIgE_tot decreases with age. Variation in sIgE_tot weakly associates with asthma control but not with exacerbation.

Fibroblast-specific integrin-alpha V differentially regulates type 17 and type 2 driven inflammation and fibrosis

Fibroproliferative diseases affect a significant proportion of the world's population. Despite this, core mechanisms driving organ fibrosis of diverse etiologies remain ill defined. Recent studies suggest that integrin-alpha V serves as a master driver of fibrosis in multiple organs. Although diverse mechanisms contribute to the progression of fibrosis, TGF-β and IL-13 have emerged as central mediators of fibrosis during type 1/type 17, and type 2 polarized inflammatory responses, respectively. To investigate if integrin-alpha V interactions or signaling is critical to the development of type 2 fibrosis, we analyzed fibroblast-specific integrin-alpha V knockout mice in three type 2-driven inflammatory disease models. While we confirmed a role for integrin-alpha V in type 17-associated fibrosis, integrin-alpha V was not critical to the development of type 2-driven fibrosis. Additionally, our studies support a novel mechanism through which fibroblasts, via integrin-alpha V expression, are capable of regulating immune polarization. We show that when integrin-alpha V is deleted on fibroblasts, initiation of type 17 inflammation is inhibited leading to a deregulation of type 2 inflammation. This mechanism is most evident in a model of severe asthma, which is characterized by a mixed type 2/type 17 inflammatory response. Together, these findings suggest dual targeting of integrin-alpha V and type 2 pathways may be needed to ameliorate fibrosis and prevent rebound of opposing pro-fibrotic and inflammatory mechanisms. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A sputum 6-gene signature predicts future exacerbations of poorly controlled asthma

BACKGROUND

Improved diagnostic tools for predicting future exacerbation frequency in asthmatic patients are required. A sputum gene expression signature of 6 biomarkers (6-gene signature [6GS], including Charcot-Leyden crystal galectin [CLC]; carboxypeptidase 3 [CPA3]; deoxyribonuclease 1-like 3 [DNASE1L3]; alkaline phosphatase, liver/bone/kidney [ALPL]; CXCR2; and IL1B) predicts inflammatory and treatment response phenotypes in patients with stable asthma. Recently, we demonstrated that azithromycin (AZM) add-on treatment in patients with uncontrolled moderate-to-severe asthma significantly reduced asthma exacerbations (AMAZES clinical trial).

OBJECTIVES

We sought to test whether the 6GS predicts future exacerbation and inflammatory phenotypes in a subpopulation of AMAZES and to test the effect of AZM therapy on 6GS expression and prognostic capacity.

METHODS

One hundred forty-two patients (73 placebo-treated and 69 AZM-treated patients) had sputum stored for quantitative PCR of 6GS markers at baseline and after 48 weeks of treatment. Logistic regression and receiver operating characteristic and area under the curve (AUC) determination were performed on baseline measures, and in an exploratory analysis the predictive value of the 6GS was compared with conventional biomarkers for exacerbation and inflammatory phenotypes.

RESULTS

The 6GS significantly predicted all future exacerbation phenotypes tested. Calculated AUCs for the 6GS were significantly greater than AUCs for peripheral blood eosinophil counts, sputum neutrophil counts, and combined sputum eosinophil and neutrophil counts. 6GS AUCs were also numerically but not significantly greater than those for fractional exhaled nitric oxide values and sputum eosinophil counts. AZM treatment altered neither 6GS expression nor the predictive capacity of the 6GS for future exacerbation phenotypes. The 6GS was a significant predictor of airway inflammatory phenotype in this population.

CONCLUSION

We demonstrate that a sputum gene signature can predict future exacerbation phenotypes of asthma, with the greatest biomarker performance in identifying those who would experience frequent severe exacerbations. AZM therapy did not modify 6GS expression or biomarker performance, suggesting the therapeutic action of AZM is independent of 6GS-related inflammatory pathways.

Omalizumab and unmet needs in severe asthma and allergic comorbidities in Japanese children

Childhood asthma is one condition within a family of allergic diseases, which includes allergic rhinitis, atopic dermatitis, and food allergy, among others. Omalizumab is an anti-IgE antibody therapy that was approved in Japan for children with asthma and added to the Japanese pediatric asthma guidelines in 2017. This review highlights the Japanese clinical perspectives in pediatric allergic asthma, and consideration for allergic comorbidities, and reflects on omalizumab clinical trials in progress to present comprehensive future opportunities.

[Asthma exacerbations in adults: Preventing and treat]

Exacerbations of asthma are still responsible for 900 deaths per year in France, most of which are considered preventable. They have a major impact on the quality of life of patients and are responsible for a large part of the socio-economic cost of asthma in France. Exacerbations of asthma can be partly prevented by inhaled corticosteroid treatment as controller therapy, at a dose adapted to the level of control of symptoms and the management of aggravating factors. Every patient should benefit from a written action plan that allows them to start oral corticosteroid therapy as soon as possible during an exacerbation. The treatment combines short-acting bronchodilators with systemic corticosteroids. Systemic antibiotic therapy has no place in the treatment of exacerbations. The patient must be seen early in the course of an exacerbation of asthma to review all of his follow-up.

Factors associated with exacerbations among adults with asthma according to electronic health record data

BACKGROUND

Asthma is a chronic inflammatory lung disease that affects 18.7 million U.S. adults. Electronic health records (EHRs) are a unique source of information that can be leveraged to understand factors associated with asthma in real-life populations. In this study, we identify demographic factors and comorbidities associated with asthma exacerbations among adults according to EHR-derived data and compare these findings to those of epidemiological studies.

METHODS

We obtained University of Pennsylvania Hospital System EHR-derived data for asthma encounters occurring between 2011 and 2014. Regression analyses were performed to model asthma exacerbation frequency as explained by age, sex, race/ethnicity, health insurance type, smoking status, body mass index (BMI) and various comorbidities. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2012 to compare findings with those from the EHR-derived data.

RESULTS

Based on data from 9068 adult patients with asthma, 33.37% had at least one exacerbation over the four-year study period. In a proportional odds logistic regression predicting number of exacerbations during the study period (levels: 0, 1-2, 3-4, 5+ exacerbations), after controlling for age, race/ethnicity, sex, health insurance type, and smoking status, the highest odds ratios (ORs) of significantly associated factors were: chronic bronchitis (2.70), sinusitis (1.50), emphysema (1.39), fluid and electrolyte disorders (1.35), class 3 obesity (1.32), and diabetes (1.28). An analysis of NHANES data showed associations for class 3 obesity, anemia and chronic bronchitis with exacerbation frequency in an adjusted model controlling for age, race/ethnicity, sex, financial class and smoking status.

CONCLUSIONS

EHR-derived data is helpful to understand exacerbations in real-life asthma patients, facilitating design of detailed studies and interventions tailored for specific populations.

Fractional Exhaled Nitric Oxide-Assisted Management of Uncontrolled Persistent Asthma: A Real-World Prospective Observational Study

CONTEXT

The utility of fractional exhaled nitric oxide (FeNO) measurement in real-world asthma management requires investigation.

OBJECTIVE

To determine whether FeNO-assisted care added to standard asthma management improves asthma control in a managed care organization.

DESIGN

Prospective observational study in patients aged 12 years and older with uncontrolled persistent asthma identified during a scheduled visit to an Allergy Department that routinely used FeNO (FeNO-assisted care, n = 426) vs visits to 4 Allergy Departments that did not, but followed routine guideline-based care (standard care, n = 925). The FeNO-assisted care was based on FeNO level, asthma control status, and step-care level.

MAIN OUTCOME MEASURES

Composite primary outcome was 1 or more asthma exacerbations or 7 or more dispensed canisters containing short-acting β2-agonists in the follow-up year. Inverse probability of treatment weighting propensity scoring balanced covariates, and multivariable regression analyses compared outcomes between groups.

RESULTS

Compared with standard care, FeNO-assisted care was not associated with reducing the primary composite outcome (adjusted risk ratio = 0.94, 95% confidence interval = 0.69-1.29, p = 0.71), nor with a reduction in asthma exacerbations or dispensing of 7 or more short-acting β2-agonist canisters as separate outcomes. In an atopic subgroup with aeroallergen sensitization, the composite outcome was similar between groups, but the rate of asthma exacerbations was lower with FeNO-assisted treatment (adjusted rate ratio = 0.67, 95% confidence interval = 0.49-0.91, p = 0.01).

CONCLUSION

These findings suggest future studies of FeNO-assisted care should be directed at the atopic phenotype.

Pathophysiological Mechanisms of Asthma

The recent Lancet commission has highlighted that "asthma" should be used to describe a clinical syndrome of wheeze, breathlessness, chest tightness, and sometimes cough. The next step is to deconstruct the airway into components of fixed and variable airflow obstruction, inflammation, infection and altered cough reflex, setting the airway disease in the context of extra-pulmonary co-morbidities and social and environmental factors. The emphasis is always on delineating treatable traits, including variable airflow obstruction caused by airway smooth muscle constriction (treated with short- and long-acting β-2 agonists), eosinophilic airway inflammation (treated with inhaled corticosteroids) and chronic bacterial infection (treated with antibiotics with benefit if it is driving the disease). It is also important not to over-treat the untreatable, such as fixed airflow obstruction. These can all be determined using simple, non-invasive tests such as spirometry before and after acute administration of a bronchodilator (reversible airflow obstruction); peripheral blood eosinophil count, induced sputum, exhaled nitric oxide (airway eosinophilia); and sputum or cough swab culture (bacterial infection). Additionally, the pathophysiology of risk domains must be considered: these are risk of an asthma attack, risk of poor airway growth, and in pre-school children, risk of progression to eosinophilic school age asthma. Phenotyping the airway will allow more precise diagnosis and targeted treatment, but it is important to move to endotypes, especially in the era of increasing numbers of biologicals. Advances in -omics technology allow delineation of pathways, which will be particularly important in TH2 low eosinophilic asthma, and also pauci-inflammatory disease. It is very important to appreciate the difficulties of cluster analysis; a patient may have eosinophilic airway disease because of a steroid resistant endotype, because of non-adherence to basic treatment, and a surge in environmental allergen burden. Sophisticated -omics approaches will be reviewed in this manuscript, but currently they are not being used in clinical practice. However, even while they are being evaluated, management of the asthmas can and should be improved by considering the pathophysiologies of the different airway diseases lumped under that umbrella term, using simple, non-invasive tests which are readily available, and treating accordingly.

Life Cycle of Childhood Asthma: Prenatal, Infancy and Preschool, Childhood, and Adolescence

Asthma is a heterogeneous developmental disorder influenced by complex interactions between genetic susceptibility and exposures. Wheezing in infancy and early childhood is highly prevalent, with a substantial minority of children progressing to established asthma by school age, most of whom are atopic. Adolescence is a time of remission of symptoms with persistent lung function deficits. The transition to asthma in adulthood is not well understood.

Systematic literature review of the clinical, humanistic, and economic burden associated with asthma uncontrolled by GINA Steps 4 or 5 treatment

OBJECTIVE

This study sought to characterize the epidemiologic, clinical, humanistic, and economic burden of patients with asthma uncontrolled by GINA Steps 4 or 5 treatment (severe, uncontrolled asthma [SUA]).

METHODS

A systematic literature review adhering to PRISMA guidelines was performed. Relevant publications were searched for in MEDLINE and EMBASE from January 2004 to September 2016 and in a conference proceedings database from January 2012 to October 2016. Studies were screened using the Population, Intervention, Comparator, Outcomes, Study Design, and Time (PICOS-T) framework. Studies of SUA with observational (prospective and retrospective), randomized, or nonrandomized study designs; adult patient populations; sample sizes ≥20 patients; epidemiologic or clinical outcomes, patient-reported outcomes (PROs), or economic outcomes were included. For our analysis, SUA was defined as inadequate control of asthma, despite the use of medium- to high-dosage inhaled corticosteroids and at least one additional treatment.

RESULTS

A total of 195 articles reporting unique study populations were included. Prevalence of SUA was as great as 87.4% for patients with severe asthma, although values varied depending on the criteria used to define asthma control. Compared with patients with severe asthma who were controlled, patients with SUA experienced more symptoms, night-time awakenings, rescue medication use, and worse PROs. SUA-associated costs were 3-times greater than costs for patients with severe, controlled disease.

CONCLUSION

Despite the availability of approved asthma treatments, this literature analysis confirms that SUA poses a substantial epidemiologic, clinical, humanistic, and economic burden. Published data are limited for certain aspects of SUA, highlighting a need for further research.

Impact of Abdominal Visceral Adiposity on Adult Asthma Symptoms

BACKGROUND

Previous studies have shown the association of anthropometric measures with poor asthma symptoms, especially among women. However, the potential influence of visceral adiposity on asthma symptoms has not been investigated well.

OBJECTIVE

In this study, we have evaluated whether visceral adiposity is related to poor adult asthma symptoms independent of anthropometric measures and sex. If this relationship presented, we investigated whether it is explained by influence on pulmonary functions and/or obesity-related comorbidities.

METHODS

We analyzed data from 206 subjects with asthma from Japan. In addition to anthropometric measures (body mass index and waist circumference), abdominal visceral and subcutaneous fat were assessed by computed tomography scan. Quality of life was assessed using the Japanese version of the Asthma Quality of Life Questionnaire.

RESULTS

All obesity indices had inverse association with reduced asthma quality of life among females. However, only the visceral fat area showed a statistical inverse association with Asthma Quality of Life Questionnaire in males. Only abdominal visceral fat was associated with higher gastroesophageal reflux disease and depression scores. Although all obesity indices showed inverse association with functional residual capacity, only visceral fat area had a significant inverse association with FEV₁ % predicted, independent of other obesity indices.

CONCLUSIONS

Regardless of sex, abdominal visceral fat was associated with reduced asthma quality of life independent of other obesity indices, and this may be explained by the impact of abdominal visceral fat on reduced FEV₁ % predicted and higher risk for gastroesophageal reflux disease and depression. Therefore, visceral adiposity may have more clinical influence than any other obesity indices on asthma symptoms.

Children with Obesity and Asthma: Which Are the Best Options for Their Management?

Obesity and asthma are complex disorders related to gene-environment interactions and various lifestyle factors. At present, they represent two of the most significant paediatric health problems worldwide, particularly in industrialized nations. The aim of this narrative review is to evaluate possible therapeutic strategies to manage asthma in children with overweight/obesity. PubMed was used to search for all of the studies published from January 2008 to June 2018 using the following key words: “asthma” and “overweight” or “obesity” or “obese” and “children” or “paediatric”. The literature review showed that growing evidence underlines the existence of an “obese asthma” phenotype characterised by difficult-to-control asthma with additional symptoms, worse control, more frequent and severe exacerbations, reduced response to inhaled corticosteroids, and lower quality of life than other phenotypes. Currently, therapeutic strategies centred on prevention are suggested and the development of resources to assist families with weight loss strategies seems useful for effective weight control and optimal asthma management. Studies on vitamin D supplementation and further knowledge are needed to better define the best therapeutic options to manage asthma in children with overweight/obesity and to reduce the onset and severity of this chronic respiratory disease through the design of a multifactorial intervention.

Inflammatory and Comorbid Features of Children Admitted to a PICU for Status Asthmaticus

OBJECTIVES

To determine risk factors associated with admission to a PICU with or without endotracheal intubation for an asthma exacerbation. We hypothesized that children with critical and near-fatal asthma would have distinguishing clinical features but varying degrees of asthma severity and measures of type 2 inflammation.

DESIGN

Retrospective analysis of prospectively collected data of children with asthma recruited into outpatient asthma clinical research studies at Emory University between 2004 and 2015.

SETTING

Large, free-standing academic quaternary care children's hospital in Atlanta, GA.

PATIENTS

Children 6-18 years old with physician-diagnosed and confirmed asthma.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 579 children were analyzed with 170 children (29.4%) being admitted to the PICU for an asthma exacerbation in their lifetime. Of these 170 children with a history of critical asthma, 24.1% were classified as having mild-to-moderate asthma, and 83 of 170 children (48.8%) had been intubated and experienced near-fatal asthma. Multiple logistic regression was used to identify risk factors associated with increased odds of PICU admission with or without endotracheal intubation. Hospitalization within the prior 12 months of survey (odds ratio, 8.19; 95% CI, 4.83-13.89), a history of pneumonia (odds ratio, 2.56; 95% CI, 1.52-4.29), having a designation of increased chronic asthma severity on high-dose inhaled corticosteroids (odds ratio, 2.76; 95% CI, 1.62-4.70), having a father with asthma (odds ratio, 2.15; 95% CI, 1.23-3.76), living in a region with a higher burden of poverty (odds ratio, 1.28; 95% CI, 1.02-1.61), and being of black race (odds ratio, 2.01; 95% CI, 1.05-3.84) were all associated with increased odds of PICU admission with or without intubation.

CONCLUSIONS

Our findings suggest that there are factors associated with critical and near-fatal asthma, distinct from the chronic asthma severity designations, that should be the focus of future investigation.

Non-eosinophilic asthma: current perspectives

Although non-eosinophilic asthma (NEA) is not the best known and most prevalent asthma phenotype, its importance cannot be underestimated. NEA is characterized by airway inflammation with the absence of eosinophils, subsequent to activation of non-predominant type 2 immunologic pathways. This phenotype, which possibly includes several not well-defined subphenotypes, is defined by an eosinophil count <2% in sputum. NEA has been associated with environmental and/or host factors, such as smoking cigarettes, pollution, work-related agents, infections, and obesity. These risk factors, alone or in conjunction, can activate specific cellular and molecular pathways leading to non-type 2 inflammation. The most relevant clinical trait of NEA is its poor response to standard asthma treatments, especially to inhaled corticosteroids, leading to a higher severity of disease and to difficult-to-control asthma. Indeed, NEA constitutes about 50% of severe asthma cases. Since most current and forthcoming biologic therapies specifically target type 2 asthma phenotypes, such as uncontrolled severe eosinophilic or allergic asthma, there is a dramatic lack of effective treatments for uncontrolled non-type 2 asthma. Research efforts are now focusing on elucidating the phenotypes underlying the non-type 2 asthma, and several studies are being conducted with new drugs and biologics aiming to develop effective strategies for this type of asthma, and various immunologic pathways are being scrutinized to optimize efficacy and to abolish possible adverse effects.

Clinical Characteristics of Patients with Chronic Rhinosinusitis without Nasal Polyps in an Academic Setting

BACKGROUND

Although patients with chronic rhinosinusitis without nasal polyps (CRSsNP) represent a majority of the chronic rhinosinusitis (CRS) population, they have not been completely characterized phenotypically.

OBJECTIVE

To perform a comprehensive phenotypic characterization of subjects with CRSsNP, using CRS with nasal polyps (CRSwNP) as a comparator.

METHODS

Patients with a history of CRS with positive sinus computed tomography (>18 years old) evaluated in the allergy/immunology or otolaryngology clinics of an academic center between 2002 and 2012 were identified via International Classification of Diseases, Ninth Revision codes. A retrospective chart review was performed on a subset of 507 patients with CRSsNP and 874 with CRSwNP. Characteristics analyzed included demographics, comorbid conditions, and radiologic sinus severity.

RESULTS

Of the total CRS population, approximately 82% had CRSsNP and 18% had CRSwNP. Of the 507 patients in the CRSsNP group, 319 (63%) were female compared with 393 of 847 (45%) in the CRSwNP group. The prevalence of atopy was 52% in CRSsNP versus 76% in CRSwNP (P < .0001). In CRSsNP, atopic patients had more severe radiographic disease compared with nonatopic patients (P < .005). The prevalence of asthma was 36% in CRSsNP versus 56% in CRSwNP (P < .0001). Comorbid asthma was not associated with radiographic sinus disease severity in CRSsNP but was associated with severity in CRSwNP (P < .0001).

CONCLUSIONS

The relative prevalence of CRS phenotypes in the western population is approximately 80% CRSsNP and 20% CRSwNP. Patients with CRSsNP were predominantly female, whereas patients with CRSwNP were predominantly male. The prevalence of asthma was higher in our cohort of patients with CRSsNP than previously described. Atopy was associated with more severe radiographic sinonasal disease in CRSsNP, whereas asthma was not associated with radiographic sinonasal disease severity.

A pilot randomized controlled trial on the impact of text messaging check-ins and a web-based asthma action plan versus a written action plan on asthma exacerbations

OBJECTIVE

We compared electronic asthma action plans (eAAP) supported by automated text messaging service (SMS) with written asthma action plans (AAP) on assessing acceptability and asthma control improvement. We hypothesized that the patients in eAAP group would have more improvements in their quality of life, asthma control and decreased asthma exacerbations.

METHODS

Patients with physician-diagnosed asthma having at least one asthma exacerbation in the previous 12 months were recruited. Participants received individualized action plans and were randomly assigned into either the intervention (eAAP) or control (AAP) group. Intervention participants received weekly SMS, triggering assessment of asthma control and viewing their eAAP. We assessed applicability of Telehealth platform on asthma exacerbations, asthma control, and quality of life over a 12-month period.

RESULTS

106 patients were enrolled (eAAP = 52, AAP = 54). The cumulative response rate to all weekly SMS check-ins was 68.4%. Overall, 28% of patients checked into their eAAP during the intervention period. There were fewer exacerbations in the eAAP group (18%) compared to the AAP group (RR = 0.82 [95%CI 0.49, 1.36]), (P = 0.44). The mean scores for asthma control and quality of life were higher in the eAAP group compared to the AAP group by 4% (RR = 1.04 [95%CI 0.83, 1.30]), (P =  0.73) and 5.5% (RR = 1.06 [95%CI 0.87, 1.28]), (P = 0.59), respectively, but were not statistically significant.

CONCLUSIONS

We demonstrated that the eAAP presented improved asthma control outcomes, but as expected the sample size was inadequate to show a significant difference, but based on this pilot study we plan a larger appropriately powered randomized controlled trial (RCT).

MicroRNA-146a is induced by inflammatory stimuli in airway epithelial cells and augments the anti-inflammatory effects of glucocorticoids

Background

MicroRNAs (miRNAs) are emerging as central regulators of inflammation, but their role in asthma and airway epithelial cells is not well studied. Glucocorticoids are the cornerstone of therapy in asthma and other inflammatory disease, yet their mechanisms of action are not completely elucidated, and it is not clear whether miRNAs modulate their effects.

Objective

We aimed to identify miRNAs that regulate cytokine and chemokine expression in airway epithelial cells and whether these miRNAs are subject to the effects of glucocorticoids.

Methods and results

MicroRNAomic analyses of immortalized, normal human bronchial epithelial cells identified 7 miRNAs that were altered by inflammatory cytokine treatment and 22 that were regulated by glucocorticoids (n = 3 for each treatment condition). MiR-146a emerged as a central candidate, whose expression was induced by TNF-α and repressed by glucocorticoids. Its role as a candidate in asthmatic inflammation was supported by expression profiling in human asthmatics, which showed that plasma miR-146a expression was elevated in asthma and associated with measures related to worse asthma outcomes, including elevated blood eosinophil counts, higher asthma control questionnaire scores, and need for higher doses of inhaled glucocorticoids. However, transfection of miR-146a in A549 cells treated with TNF-α +/- glucocorticoids produced an anti-inflammatory effect and increased efficacy of glucocorticoids.

Conclusions

We propose a model whereby miR-146a is induced by inflammatory conditions as a feedback mechanism to limit inflammation. Exogenous administration of miR-146a augmented the effects of glucocorticoids and could be a novel therapeutic strategy to enhance efficacy of these medications.

Susceptibility to exacerbations in Black adults with asthma

OBJECTIVE

Exacerbations account for much of the morbidity in asthma. In a large intervention study, we sought to test the hypothesis that a Black adult exacerbation-prone phenotype - a group of Black people with asthma who are at high risk of repeat exacerbation within one year - exists in asthma independent of clinical control.

METHODS

We analyzed exacerbation risk factors in 536 self-identified Black Americans with asthma eligible for, or on, Step 3 National Asthma Education and Prevention Program (NAEPP) therapy who participated in a randomized 6-18 month trial of tiotropium versus long acting beta agonist as add-on therapy to inhaled corticosteroids. Exacerbations were defined as events treated by oral or systemic corticosteroids. Clinical control was assessed by a validated asthma control questionnaire (ACQ5).

RESULTS

Exacerbations became more likely with loss of clinical control. The mean baseline ACQs for exacerbators and non-exacerbators were 2.41 and 1.91, respectively (p < 0.001). The strongest independent factor associated with exacerbations across all ACQ levels was an exacerbation in the preceding year (adjusted OR 3.26; p < 0.001). The severity of prior exacerbations did not correlate with the likelihood of a future exacerbation. Lower baseline FEV1/FVC was also associated with increased risk of exacerbations.

CONCLUSIONS

Even though exacerbations increase with loss of clinical control, an exacerbation susceptibility phenotype exists in Black adults with asthma, independent of clinical control. This phenotype requires precision therapeutic targeting.

Asthma: Differential Diagnosis and Comorbidities

Childhood asthma remains a multifactorial disease with heterogeneous clinical phenotype and complex genetic inheritance. The primary aim of asthma management is to achieve control of symptoms, in order to reduce the risk of future exacerbations and progressive loss of lung function, which results especially challenging in patients with difficult asthma. When asthma does not respond to maintenance treatment, firstly, the correct diagnosis needs to be confirmed and other diagnosis, such as cystic fibrosis, primary ciliary dyskinesia, immunodeficiency conditions or airway and vascular malformations need to be excluded. If control remains poor after diagnostic confirmation, detailed assessments of the reasons for asthma being difficult-to-control are needed. Moreover, all possible risk factors or comorbidities (gastroesophageal reflux, rhinosinusitis, dysfunctional breathing and/or vocal cord dysfunction, obstructive sleep apnea and obesity) should be investigated. At the same time, the possible reasons for poor symptom control need to be find in all modifiable factors which need to be carefully assessed. Non-adherence to medication or inadequate inhalation technique, persistent environmental exposures and psychosocial factors are, currently, recognized as the more common modifiable factors. Based on these premises, investigation and management of asthma require specialist multidisciplinary expertise and a systematic approach to characterizing patients' asthma phenotypes and delivering individualized care. Moreover, since early wheezers are at higher risk of developing asthma, we speculate that precocious interventions aimed at early diagnosis and prevention of modifiable factors might affect the age at onset of wheezing, reduce the prevalence of persistent later asthma and determine long term benefits for lung health.

Involvement and Possible Role of Eosinophils in Asthma Exacerbation

Eosinophils are involved in the development of asthma exacerbation. Recent studies have suggested that sputum and blood eosinophil counts are important factors for predicting asthma exacerbation. In severe eosinophilic asthma, anti-interleukin (IL)-5 monoclonal antibody decreases blood eosinophil count and asthma exacerbation frequency. However, even in the absence of IL-5, eosinophilic airway inflammation can be sufficiently maintained by the T helper (Th) 2 network, which comprises a cascade of vascular cell adhesion molecule-1/CC chemokines/eosinophil growth factors, including granulocyte-macrophage colony-stimulating factor (GM-CSF). Periostin, an extracellular matrix protein and a biomarker of the Th2 immune response in asthma, directly activates eosinophils in vitro. A major cause of asthma exacerbation is viral infection, especially rhinovirus (RV) infection. The expression of intercellular adhesion molecule (ICAM)-1, a cellular receptor for the majority of RVs, on epithelial cells is increased after RV infection, and adhesion of eosinophils to ICAM-1 can upregulate the functions of eosinophils. The expressions of cysteinyl leukotrienes (cysLTs) and CXCL10 are upregulated in virus-induced asthma. CysLTs can directly provoke eosinophilic infiltration in vivo and activate eosinophils in vitro. Furthermore, eosinophils express the CXC chemokine receptor 3, and CXCL10 activates eosinophils in vitro. Both eosinophils and neutrophils contribute to the development of severe asthma or asthma exacerbation. IL-8, which is an important chemoattractant for neutrophils, is upregulated in some cases of severe asthma. Lipopolysaccharide (LPS), which induces IL-8 from epithelial cells, is also increased in the lower airways of corticosteroid-resistant asthma. IL-8 or LPS-stimulated neutrophils increase the transbasement membrane migration of eosinophils, even in the absence of chemoattractants for eosinophils. Therefore, eosinophils are likely to contribute to the development of asthma exacerbation through several mechanisms, including activation by Th2 cytokines, such as IL-5 or GM-CSF or by virus infection-related proteins, such as CXCL10, and interaction with other cells, such as neutrophils.

Implication of fraction of exhaled nitric oxide and blood eosinophil count in severe asthma

BACKGROUND

Severe asthma is a complex disease with heterogeneous features and involves type 2 airway inflammation, including eosinophil accumulation. Surrogate biomarkers, fraction of exhaled nitric oxide (FeNO) and blood eosinophil count (b-EOS), may predict eosinophilic airway inflammation. Here we investigated clinical characteristics of severe asthma phenotype using a combined analysis of FeNO and b-EOS.

METHODS

This retrospective study examined clinical data of patients with severe asthma (N = 107; median age, 64 years) treated at Saitama Medical University Hospital from 2009 to 2016. Thresholds of FeNO and b-EOS for sputum eosinophil ratio ≥2% were determined using receiver operating characteristic curve (ROC) analysis. Clinical characteristics were analyzed after classifying patients into four subgroups according to these thresholds.

RESULTS

Of 39 induced sputum samples examined, ROC area under the curve for predicting sputum eosinophilia was 82.0% (p = 0.001) for b-EOS and 77.0% (p = 0.006) for FeNO at optimal cut-off values of ≥300/μL and ≥25 ppb, respectively. The number of sensitized allergens was higher in the high FeNO/low b-EOS and high FeNO/high b-EOS subgroups (p < 0.05). The prevalence of chronic sinusitis was higher in the low FeNO/high b-EOS and high FeNO/high b-EOS subgroups (p = 0.04). The high FeNO/high b-EOS subgroup included the largest proportion (approximately 40%) of patients experiencing frequent severe exacerbations. Both low FeNO/low b-EOS and high FeNO/low b-EOS subgroups showed less severe exacerbations.

CONCLUSIONS

Combined evaluation of FeNO and b-EOS can identify patients with frequent exacerbations and stratify the appropriate therapy for type 2 inflammation-predominant severe asthma.

Translating Asthma: Dissecting the Role of Metabolomics, Genomics and Personalized Medicine

The management of asthma has largely stagnated over the last 25 years, but we are at the dawning of a new age wherein -omics technology can help us manage the disease objectively and rationally. Even in this new scientific age, getting the basics of asthma management right remains essential. The new technologies which can be applied to multiple biological samples include genomics (study of the genome), transcriptomics (gene transcription), lipidomics, proteomics and metabolomics (lipids, proteins and metabolites, respectively) and breathomics, using exhaled breath as a source of biomarkers, which is of particular interest in view of its non-invasive nature in pediatrics. Important applications will include the diagnosis of airways disease, including its components; the pathways driving airway pathology; monitoring the response to treatment; and measuring future risk (asthma attacks, poor lung growth trajectory). With the advent of a wide range of novel biologicals to treat asthma, -omics technology to personalize therapy will be especially important. The U-BIOPRED (Europe) and SARP (USA) groups have been most active in this field, especially using bronchoscopically obtained samples to perform cluster analyses to define new asthma endotypes. However, stability over time and consistency between investigators is imperfect. This is perhaps unsurprising; results of biomarker studies in asthma will be a composite of the underlying disease, the (variable) effects of adverse drivers such as allergen exposure and pollution, the effects of treatment, and the effects of adherence or otherwise to treatment. Ultimately, the aim should be an exhaled breath based tool with a rapid result that can be used as a routine in the clinic. However, at the moment, there are as yet no clinical applications in children of -omics technology.

Use of biomarkers to identify phenotypes and endotypes of severeasthma

OBJECTIVE

Severe asthma can be classified into phenotypes and endotypes, which may inform clinicians about inflammatory pathways leading to disease and ultimately guide optimal therapeutic strategy. Biomarkers, objectively measurable characteristics of the disease, are of increasing interest to clinicians and researchers as powerful tools to distinguish among the severe asthma phenotypes and endotypes. The objective of this review is to highlight current knowledge of biomarker applications to identify phenotypes and endotypes of severe asthma.

DATA SOURCES

Sources used include observational cohorts, clinical trials, translational studies, comprehensive reviews, and expert/taskforce statements.

STUDY SELECTIONS

Included studies were selected for their relevance to the topic and for strength of data or study design.

RESULTS

In severe asthma, biomarkers can be used for diagnosis of phenotype or endotype, can also be predictive of clinical outcomes or response to therapy, and may be dynamic with time or therapy. Fully determining phenotype or endotype of severe asthma will require interpretation of combinations of commercially available biomarkers.

CONCLUSION

Biomarkers have multiple potential clinical applications in severe asthma. Novel biomarkers may add accuracy to this field.

Association between blood eosinophil count with asthma hospital readmissions

INTRODUCTION

The presence of eosinophils in asthma inflammation is a relevant factor in the pathophysiology of the disease, however the relationship between the blood eosinophil count (BEC) with asthma severity and prognosis is still under debate. The aim of this work is to analyze the relationship between the BEC levels and hospital readmissions in patients with asthma.

MATERIAL AND METHODS

A review was retrospectively carried out on all admissions of patients over 18 years old due to exacerbation of asthma occurring in our hospital between the years 2000 and 2010. The personal characteristics and the asthma personal history of each patient were recorded. The BEC was determined from the first blood sample taken from the patient after their arrival at the hospital. Hospital early, late and frequent readmissions were analyzed using 4 cut-off points; less than 150 eosinophils/μL vs ≥150/μL, less than 200 vs 200 /μL, less than 300 vs ≥300/μL, and less than 400 vs ≥400/μL.

RESULTS

We have included 1316 patients, 70% of whom are women, as well as a mean age of 60 years, and a mean FEV1 of 73.5% of the reference value. The mean eosinophil blood count was 201.7 cells/μL. A BEC ≥300 cells/μL showed a reduction of risk of late readmission of 42%, a BEC ≥400 cells/μL showed a reduction in late readmission risk of 41% and decrease in frequent late readmission of 63%.

CONCLUSIONS

Our study appears to support that an elevated BEC is associated with a lower incidence of asthma hospital readmissions.

Comorbid "treatable traits" in difficult asthma: Current evidence and clinical evaluation

The care of patients with difficult-to-control asthma ("difficult asthma") is challenging and costly. Despite high-intensity asthma treatment, these patients experience poor asthma control and face the greatest risk of asthma morbidity and mortality. Poor asthma control is often driven by severe asthma biology, which has appropriately been the focus of intense research and phenotype-driven therapies. However, it is increasingly apparent that extra-pulmonary comorbidities also contribute substantially to poor asthma control and a heightened disease burden. These comorbidities have been proposed as "treatable traits" in chronic airways disease, adding impetus to their evaluation and management in difficult asthma. In this review, eight major asthma-related comorbidities are discussed: rhinitis, chronic rhinosinusitis, gastroesophageal reflux, obstructive sleep apnoea, vocal cord dysfunction, obesity, dysfunctional breathing and anxiety/depression. We describe the prevalence, impact and treatment effects of these comorbidities in the difficult asthma population, emphasizing gaps in the current literature. We examine the associations between individual comorbidities and highlight the potential for comorbidity clusters to exert combined effects on asthma outcomes. We conclude by outlining a pragmatic clinical approach to assess comorbidities in difficult asthma.

Prospective predictors of exacerbation status in severe asthma over a 3-year follow-up

BACKGROUND

A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor.

OBJECTIVE

This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma.

METHODS

We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status."

RESULTS

Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05).

CONCLUSIONS AND CLINICAL RELEVANCE

Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."

Performance of the Asthma Impact on Quality of Life Scale (A-IQOLS) in diverse asthma research populations and demographic subgroups

BACKGROUND

The Asthma Impact on Quality of Life Scale (A-IQOLS) assesses the patient-perceived negative effect of asthma on quality of life. Its standard error of measurement is known; it has strong construct, convergent, and divergent validity; and it provides information that is unique among asthma outcome measures.

OBJECTIVE

We sought to characterize the psychometric properties of the A-IQOLS and its suitability for use in demographically and clinically diverse adult asthmatic populations.

METHODS

Data from participants in 5 independent asthma studies, with samples ranging from patients with well-controlled moderate asthma to patients with severe poorly controlled asthma, were pooled to determine the psychometric performance of A-IQOLS scores overall and in multiple demographic, disease status, and study subgroups.

RESULTS

Pooled sample (n = 597) age averaged 45 years; 66% were female, 65% were white, 22% were African American, 11% were Hispanic, and 11% had a high school education or less. The rated importance of its underlying life dimensions and associations between A-IQOLS scores and lung function, symptom, Asthma Control Test, Juniper Mini Asthma Quality of Life Questionnaire, and Marks Asthma Quality of Life Questionnaire scores was very similar, regardless of patients' demographic and clinical characteristics. A-IQOLS scores discriminated among the individual study samples, as well as other patient-reported symptom and functional status measures. Distribution and anchor-based considerations suggest an A-IQOLS minimum clinically important difference in the vicinity of 0.50 and not less than 0.33 scale score units.

CONCLUSIONS

A-IQOLS is valid for research and potentially clinical use in demographically and clinically diverse patients.

Identification of patterns of factors preceding severe or life-threatening asthma exacerbations in a nationwide study

BACKGROUND

Reducing near-fatal asthma exacerbations is a critical problem in asthma management.

OBJECTIVES

To determine patterns of factors preceding asthma exacerbations in a real-world setting.

METHODS

In a nationwide prospective study of 190 patients who had experienced near-fatal asthma exacerbation, cluster analysis was performed using asthma symptoms over the 2-week period before admission.

RESULTS

Three distinct clusters of symptoms were defined employing the self-reporting of a visual analogue scale. Cluster A (42.1%): rapid worsening within 7.4 hours from moderate attack to admission, young to middle-aged patients with low Body mass index and tendency to depression who had stopped anti-asthma medications, smoked, and hypersensitive to environmental triggers and furred pets. Cluster B (40.0%): fairly rapid worsening within 48 hours, mostly middle-aged and older, relatively good inhaled corticosteroid (ICS) or ICS/long-acting beta-agonist (LABA) compliance, and low perception of dyspnea. Cluster C (17.9%): slow worsening over 10 days before admission, high perception of dyspnea, smokers, and chronic daily mild-moderate symptoms. There were no differences in overuse of short-acting beta-agonists, baseline asthma severity, or outcomes after admission for patients in these 3 clusters.

CONCLUSION

To reduce severe or life-threatening asthma exacerbation, personalized asthma management plans should be considered for each cluster. Improvement of ICS and ICS/LABA compliance and cessation of smoking are important in cluster A. To compensate for low perception of dyspnea, asthma monitoring of peak expiratory flow rate and/or exhaled nitric oxide would be useful for patients in cluster B. Avoidance of environmental triggers, increase usual therapy, or new anti-type 2 response-targeted therapies should be considered for cluster C.

Predictors of future exacerbations in a multi-ethnic Asian population with asthma

OBJECTIVE

Exacerbations are important outcomes in asthma. Risk factors for exacerbations may differ in different populations. Although various demographic and clinical variables were examined in previous studies on exacerbation risks in asthma, important variables such as ethnicity, adherence, and medication titration were not included. This study examined independent predictors of future exacerbations in a multi-ethnic asthma population in Asia, while including the variables of ethnicity, medication adherence, and medication change in our analysis.

METHODS

We recruited patients with physician-diagnosed asthma in a tertiary hospital in Singapore over a one-year period. Exacerbations requiring ≥3 days of systemic corticosteroids one year prior to study enrolment (previous exacerbations) and the year following enrolment (future exacerbations) were recorded from electronic medical records. Medication adherence was based on pharmacy refill. An increase or a decrease in the Global Initiative for Asthma treatment steps were considered to be medication up- and down-titration, respectively. A multivariate logistic regression model was constructed to determine independent predictors of future exacerbations.

RESULTS

The study cohort of 340 patients comprised mainly of Chinese (53.2%), Malay (32.9%), and Indian (9.7%) ethnicities. After multivariate analysis, only Indian ethnicity (OR 3.75, 95% CI 1.077-13.051, p = 0.038), Asthma Control Test score (OR 0.913, 95% CI 0.839-0.995, p = 0.037), and the number of previous exacerbations (OR 1.84, 95% CI 1.416-2.391, p < 0.001) were independent predictors of future exacerbations.

CONCLUSIONS

There are ethnic differences in exacerbation risk in Asian populations. Each incremental worsening of the asthma symptom control score and each additional exacerbation also increases the risk of future exacerbations.

Age and Sex Associations with Systemic Corticosteroid-Induced Morbidity in Asthma

BACKGROUND

Treatment of severe asthma may include high-dose systemic corticosteroid therapy, which is associated with substantial comorbidity. There is evidence to suggest that this burden is not evenly distributed across age, sex, and corticosteroid exposure levels.

OBJECTIVE

To examine the associations between age, sex, comorbidity, and patterns of health care cost across groups differentiated by corticosteroid exposure.

METHODS

Patients with severe asthma (n = 808) were matched by age and sex with patients with mild/moderate asthma (n = 3975) and nonasthma control subjects (n = 2412) from the Optimum Patient Care Research Database. Regression analysis was used to investigate the odds of a number of corticosteroid-induced comorbidities as it varied by cohort, age group, and sex. Prescribed drugs and publicly funded health care activity were monetized and annual costs per patient estimated.

RESULTS

Patients aged 60 years or younger with high oral corticosteroid (OCS) exposure had greater odds of osteopenia, osteoporosis, glaucoma, dyspeptic disorders, chronic kidney disease, cardiovascular disease, cataracts, hypertension, and obesity (P < .01) relative to those with mild/moderate asthma (low OCS exposure) as well as to those with no asthma. This difference in odds was much less evident in older patients. Sex-related differences for the odds of most comorbidities related to high-dose OCS were also observed. This differential pattern of comorbidity prevalence was reflected in mean health care costs per patient per year.

CONCLUSIONS

Results demonstrate important differential prevalence of corticosteroid-induced morbidity by age and sex, which is paralleled by differences in health care costs. This is important for clinicians in better understanding the risks of placing different age groups or sexes on systemic corticosteroids.

Effects of endogenous sex hormones on lung function and symptom control in adolescents with asthma

BACKGROUND

Although pre-puberty asthma is more prevalent in males, after puberty through middle-age, asthma is more prevalent in females. The surge of sex hormones with puberty might explain this gender switch.

METHODS

To examine the effects of sex hormones on lung function and symptoms with puberty, Tanner stage was assessed in 187 children 6-18 years of age (59% severe) enrolled in the NIH/NHLBI Severe Asthma Research Program (SARP). The effects of circulating sex hormones (n = 68; testosterone, dehydroepiandrosterone sulfate (DHEA-S), estrogen, and progesterone) on lung function and 4 week symptom control (ACQ6) in cross-section were tested by linear regression.

RESULTS

From pre-/early to late puberty, lung function did not change significantly but ACQ6 scores improved in males with severe asthma. By contrast females had lower post-BD FEV₁% and FVC% and worse ACQ6 scores with late puberty assessed by breast development. In males log DHEA-S levels, which increased by Tanner stage, associated positively with pre- and post-BD FEV₁%, pre-BD FVC %, and negatively (improved) with ACQ6. Patients treated with high-dose inhaled corticosteroids had similar levels of circulating DHEA-S. In females, estradiol levels increased by Tanner stage, and associated negatively with pre-BD FEV₁% and FVC %.

CONCLUSIONS

These results support beneficial effects of androgens on lung function and symptom control and weak deleterious effects of estradiol on lung function in children with asthma. Longitudinal data are necessary to confirm these cross-sectional findings and to further elucidate hormonal mechanisms informing sex differences in asthma features with puberty.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT01748175 .

Type 2 Biomarkers and Prediction of Future Exacerbations and Lung Function Decline in Adult Asthma

BACKGROUND

Type 2 biomarkers that predict both likelihood of future severe exacerbations and response to mAb therapy in asthma would be useful clinically in identifying patients both at greater risk of hospitalization and most likely to benefit from mAb therapy.

OBJECTIVE

To describe the association between type 2 biomarkers, blood eosinophils, fractional exhaled nitric oxide (Feno), serum periostin, and serum IgE, and time to severe exacerbation in a broad asthma population.

METHODS

Participants from 2 adult asthma cohorts with baseline measurements of blood eosinophils, Feno, serum periostin, and serum IgE were reviewed after at least 12 months to obtain an exacerbation history, corroborated with general practitioner and hospital medical records. The association between baseline type 2 biomarkers and time to exacerbation was described by Cox proportional hazard ratios (HRs) using multivariate models.

RESULTS

A total of 212 participants were followed for a median (range) 3.8 (1.1-5.3) years; 67 of 212 (32%) had at least 1 severe exacerbation. The HRs (95% CI) of baseline type 2 biomarkers and time to exacerbation were as follows: blood eosinophils per 0.1 × 10⁹/L increase, 0.89 (0.76-1.05), P = .17; log Feno per 0.693 increase, 0.65 (0.52-0.81), P < .001; log serum periostin per 0.693 increase, 0.62 (0.35-1.09), P = .10; log serum IgE per 0.693 increase, 0.89 (0.80-1.00), P = .05.

CONCLUSIONS

The positive association between type 2 biomarkers and risk of severe exacerbations in populations with severe refractory asthma does not extend to mild and moderate asthma. Non-type 2 asthma may represent a phenotype associated with an increased risk of severe exacerbations in a broad asthma population.

Refractory airway type 2 inflammation in a large subgroup of asthmatic patients treated with inhaled corticosteroids

BACKGROUND

Airway type 2 inflammation is usually corticosteroid sensitive, but the role of type 2 inflammation as a mechanism of asthma in patients receiving high-dose inhaled corticosteroids (ICSs) is uncertain.

OBJECTIVE

We sought to determine whether airway type 2 inflammation persists in patients treated with ICSs and to evaluate the clinical features of patients with steroid-resistant airway type 2 inflammation.

METHODS

We used quantitative PCR to generate a composite metric of type 2 cytokine gene expression (type 2 gene mean [T2GM]) in induced sputum cells from healthy control subjects, patients with severe asthma receiving ICSs (n = 174), and patients with nonsevere asthma receiving ICSs (n = 85). We explored relationships between asthma outcomes and T2GM values and the utility of noninvasive biomarkers of airway T2GM.

RESULTS

Sputum cell T2GM values in asthmatic patients were significantly increased and remained high after treatment with intramuscular triamcinolone. We used the median T2GM value as a cutoff to classify steroid-treated type 2-low and steroid-resistant type 2-high (srT2-high) subgroups. Compared with patients with steroid-treated type 2-low asthma, those with srT2-high asthma were older and had more severe asthma. Blood eosinophil cell counts predicted srT2-high asthma when body mass index was less than 40 kg/m² but not when it was 40 kg/m² or greater, whereas blood IgE levels strongly predicted srT2-high asthma when age was less than 34 years but not when it was 34 years or greater.

CONCLUSION

Despite ICS therapy, many asthmatic patients have persistent airway type 2 inflammation (srT2-high asthma), and these patients are older and have more severe disease. Body weight and age modify the performance of blood-based biomarkers of airway type 2 inflammation.

Bronchiectasis in severe asthma: Clinical features and outcomes

BACKGROUND

Bronchiectasis is increasingly being identified in patients with severe asthma and could contribute to disease severity.

OBJECTIVE

To determine the prevalence of bronchiectasis in a population of patients with severe asthma and to better characterize the clinical features of these patients and their outcomes.

METHODS

We retrospectively reviewed the medical files of 184 subjects with confirmed severe asthma who had undergone high-resolution thoracic computed tomography and compared the characteristics and outcomes of subjects with and without bronchiectasis.

RESULTS

Bronchiectasis was identified in 86 patients (47%). These patients had concomitant hypersensitivity to nonsteroidal anti-inflammatory drugs (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.00-5.03) and gastroesophageal reflux disease (OR 1.89, 95% CI 1.05-3.41) more frequently than subjects without bronchiectasis, but had less atopic dermatitis (OR 0.188, 95% CI 0.04-0.88). Subjects with bronchiectasis were more frequently hospitalized for asthma exacerbations (OR 2.09, 95% CI 1.08-4.05) and had higher blood eosinophil levels (464 vs 338; P = .005) than subjects without bronchiectasis.

CONCLUSION

Our study suggests that in subjects with severe asthma, the presence of bronchiectasis is associated with more frequent hospitalizations, concomitant gastroesophageal reflux disease, hypersensitivity to nonsteroidal anti-inflammatory drugs, and higher blood eosinophil counts. Bronchiectasis could represent an additional phenotypic feature of severe eosinophilic asthma.

Targeted Therapy for Severe Asthma: Identifying the Right Patients

Asthma affects over 300 million people worldwide. Most asthmatics are well controlled with inhaled corticosteroids and long-acting beta-agonists; however, a proportion of patients are unresponsive and attain limited disease control. This group represents a considerable healthcare and financial burden, particularly patients who experience frequent exacerbations and require hospital admission. Development of new biological agents and disease biomarkers has provided novel avenues for treatment. These treatments have been highly successful, reducing exacerbations and yielding modest improvements in quality of life and lung function. However, only a proportion of severe asthmatics respond to this targeted treatment, highlighting the heterogeneity of severe asthma. One of the first biological therapies targeted immunoglobulin E (IgE) and demonstrated modest benefit but could only be used in a subgroup of patients. Recent research has shown that treatment aimed at the T helper-2-(Th₂)-high pathways and cytokines such as interleukin (IL)-5, IL-4, and IL-13 may also be effective in another partially overlapping subgroup. A blood eosinophil count over a defined threshold (generally ≥300 cells/μl) was a reliable biomarker and identified the majority of responders in this group. Further discovery and validation of biological markers to define asthmatic phenotypes that may benefit from biological treatments remain an area of intense interest and research. We review the latest information pertaining to biological agents and demonstrate how patient responders may potentially be identified for treatment.

Severe Asthma Phenotypes - How Should They Guide Evaluation and Treatment?

Although patients with "severe" asthma tend to be characterized by ongoing symptoms and airway inflammation despite treatment with high doses of inhaled and systemic corticosteroids, there is increasing recognition of marked phenotypic heterogeneity within affected patients. Although "precision medicine" approaches for patients with severe asthma are needed, there are many hurdles that must be overcome in daily practice. The National Heart, Lung and Blood Institute's Severe Asthma Research Program (SARP) has been at the forefront of phenotype discovery in severe asthma for the past decade. SARP, along with other international groups, has described clinical severe asthma phenotypes in both adults and children that can be evaluated in the clinical setting. Although these clinical phenotypes provide a good "starting point" for addressing disease heterogeneity in severe asthma in everyday practice, more efforts are needed to understand how these phenotypes relate to underlying disease mechanisms and pharmacological treatment responses. This review highlights the clinical asthma phenotypes identified to date, their associations with underlying endotypes and potential biomarkers, and remaining knowledge gaps that must be addressed before precision medicine can become a reality for patients with severe asthma.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

Features of asthma which provide meaningful insights for understanding the disease heterogeneity

BACKGROUND

Data-driven methods such as hierarchical clustering (HC) and principal component analysis (PCA) have been used to identify asthma subtypes, with inconsistent results.

OBJECTIVE

To develop a framework for the discovery of stable and clinically meaningful asthma subtypes.

METHODS

We performed HC in a rich data set from 613 asthmatic children, using 45 clinical variables (Model 1), and after PCA dimensionality reduction (Model 2). Clinical experts then identified a set of asthma features/domains which informed clusters in the two analyses. In Model 3, we reclustered the data using these features to ascertain whether this improved the discovery process.

RESULTS

Cluster stability was poor in Models 1 and 2. Clinical experts highlighted four asthma features/domains which differentiated the clusters in two models: age of onset, allergic sensitization, severity, and recent exacerbations. In Model 3 (HC using these four features), cluster stability improved substantially. The cluster assignment changed, providing more clinically interpretable results. In a 5-cluster model, we labelled the clusters as: "Difficult asthma" (n = 132); "Early-onset mild atopic" (n = 210); "Early-onset mild non-atopic: (n = 153); "Late-onset" (n = 105); and "Exacerbation-prone asthma" (n = 13). Multinomial regression demonstrated that lung function was significantly diminished among children with "Difficult asthma"; blood eosinophilia was a significant feature of "Difficult," "Early-onset mild atopic," and "Late-onset asthma." Children with moderate-to-severe asthma were present in each cluster.

CONCLUSIONS AND CLINICAL RELEVANCE

An integrative approach of blending the data with clinical expert domain knowledge identified four features, which may be informative for ascertaining asthma endotypes. These findings suggest that variables which are key determinants of asthma presence, severity, or control may not be the most informative for determining asthma subtypes. Our results indicate that exacerbation-prone asthma may be a separate asthma endotype and that severe asthma is not a single entity, but an extreme end of the spectrum of several different asthma endotypes.

Biomarkers for severe eosinophilic asthma

The last decade has seen the approval of several new biologics for the treatment of severe asthma-targeting specific endotypes and phenotypes. This review will examine how evidence generated from the mepolizumab clinical development program showed that blood eosinophil counts, rather than sputum or tissue eosinophil counts, evolved as a pharmacodynamic and predictive biomarker for the efficacy of treatment with mepolizumab in patients with severe eosinophilic asthma. Based on the available evidence and combined with clinical judgement, a baseline blood eosinophil threshold of 150 cells/μL or greater or a historical blood eosinophil threshold of 300 cells/μL or greater will allow selection of patients with severe eosinophilic asthma who are most likely to achieve clinically significant reductions in the rate of exacerbations with mepolizumab treatment.

Internet-Based Monitoring in the Severe Asthma Research Program Identifies a Subgroup of Patients With Labile Asthma Control

BACKGROUND

We designed an Internet-Based Monitoring Systems (IBS) survey to facilitate monitoring of asthma symptoms and asthma exacerbations in the Severe Asthma Research Program (SARP). Our objective was to evaluate compliance with the IBS survey tool and to explore how data from an IBS tool can inform understanding of asthma phenotypes.

METHODS

We invited adult subjects in the SARP III cohort (N = 528) to complete a monthly IBS asthma control survey. We compared the characteristics of subjects who did and those who did not participate in the IBS survey tool. Among subjects who participated in the IBS (IBS+), we identified participants with low, medium, and high Asthma Control Test (ACT) score variability, and we explored asthma morbidity in these three participant subgroups.

RESULTS

Two hundred fifty-nine subjects participated in the IBS (IBS+) survey. Compared with subjects who did not engage with the IBS (IBS-) survey, IBS+ subjects were older and more likely to be white, college educated, and have an annual household income > $25,000, and have controlled asthma. Among IBS+ participants, the subgroup with the highest ACT score variability was more likely to have severe asthma, with a lower ACT score at baseline and increased asthma-related health-care use (often precipitated by cold and flulike illnesses). Participants with high ACT variability were also characterized by metabolic dysfunction, as evidenced by obesity and hypertension.

CONCLUSIONS

Active participation with an Internet-based symptom survey tool in patients with severe asthma is influenced by race, socioeconomic status, and asthma control. Among survey participants, a group with highly variable (labile) asthma control is identifiable as a specific subgroup with unmet treatment needs. The association of asthma lability, increased susceptibility to adverse asthma effects of cold and flulike illnesses, and metabolic dysfunction provides clues for potentially effective intervention strategies.

Baseline asthma burden, comorbidities, and biomarkers in omalizumab-treated patients in PROSPERO

BACKGROUND

Patients included in clinical trials do not necessarily reflect the real-world population.

OBJECTIVE

To understand the characteristics, including disease and comorbidity burden, of patients with asthma receiving omalizumab in a real-world setting.

METHODS

The Prospective Observational Study to Evaluate Predictors of Clinical Effectiveness in Response to Omalizumab (PROSPERO) was a US-based, multicenter, single-arm, and prospective study. Patients (≥12 years of age) with allergic asthma initiating omalizumab treatment based on physician-assessed need were included and followed for 12 months. Exacerbations, health care use, adverse events, and Asthma Control Test (ACT) scores were assessed monthly. Biomarkers (blood eosinophils, fractional exhaled nitric oxide, and periostin) were evaluated and patient-reported outcomes (Asthma Quality of Life Questionnaire for 12 Years and Older [AQLQ+12] and Work Productivity and Activity Impairment: Asthma questionnaire [WPAI:Asthma]) were completed at baseline and months 6 and 12. The Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) was completed at baseline and 12 months.

RESULTS

Most of the 806 enrollees (91.4%) were adults (mean age 47.3 years, SD 17.4), white (70.3%), and female (63.5%). Allergic comorbidity was frequently reported (84.2%), as were hypertension (35.5%) and depression (22.1%). In the 12 months before study entry, 22.1% of patients reported at least 1 asthma-related hospitalization, 60.7% reported at least 2 exacerbations, and 83.3% reported ACT scores no higher than 19 (uncontrolled asthma). Most patients had low biomarker levels based on prespecified cut-points. Baseline mean patient-reported outcome scores were 4.0 (SD 1.4) for AQLQ+12, 2.7 (SD 1.4) for MiniRQLQ, and 47.7 (SD 28.9) for WPAI:Asthma percentage of activity impairment and 33.5 (SD 28.7) for percentage of overall work impairment.

CONCLUSION

The population initiating omalizumab in PROSPERO reported poorly controlled asthma and a substantial disease burden.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01922037.

Eosinophils and eosinophil-associated diseases: An update

The goal of this series is to offer a survey of the latest literature for clinicians and scientists alike, providing a list of important recent advances relevant to the broad field of allergy and immunology. This particular assignment was to cover the topic of eosinophils. In an attempt to highlight major ideas, themes, trends, and advances relevant to basic and clinical aspects of eosinophil biology, a search of articles published since 2015 in the Journal of Allergy and Clinical Immunology and other high-impact journals was performed. Articles were then reviewed and organized, and then key findings were summarized. Given space limitations, many outstanding articles could not be included, but the hope is that what follows provides a succinct overview of recently published work that has significantly added to our knowledge of eosinophils and eosinophil-associated diseases.

Comparative features of Asthma with frequent or infrequent exacerbations: A longitudinal study of retrospective and prospective events

BACKGROUND

A "frequent exacerbator phenotype" has been described, mostly in the population of patients with severe asthma. Further data are needed on such exacerbation-prone patients in milder asthma.

AIM

To compare the characteristics of frequent and nonfrequent exacerbators in asthma of different severities and to assess the stability of the exacerbator status.

METHODS

This was an observational study comparing baseline data from frequent (≥2 exacerbations in the past year) and nonfrequent (<2 exacerbations in the past year) exacerbators. Patients were also followed up for one year. Information regarding clinical, physiologic, and inflammatory characteristics was collected at baseline and one-year follow-up.

RESULTS

Forty-seven frequent and 53 nonfrequent exacerbators were recruited. No specific clinical, physiologic, or inflammatory characteristic was observed in the frequent as compared to the nonfrequent exacerbators at baseline. Fifty-eight percent of patients reporting frequent exacerbations at baseline remained in this group after one year of follow-up. Forty-two and 62% of patients with, respectively, mild-to-moderate asthma and severe asthma had frequent exacerbations. In a post hoc analysis according to asthma severity, frequent exacerbators with severe asthma had a higher body mass index and poorer asthma control, although they reported higher adherence to medication, in comparison to frequent exacerbators with mild-to-moderate asthma. No specific characteristics could discriminate between frequent and nonfrequent exacerbators of the same asthma severity.

CONCLUSIONS

Frequent exacerbators with severe asthma present some specific characteristics not observed in frequent exacerbators with mild-to-moderate disease. However, the latter group should be identified to reassess treatment needs and potential contributing factors.