Factors Associated with Frequent Exacerbations in the UK Severe Asthma Registry

Clinical and Economic Burden of Severe Asthma With Low Blood Eosinophil Counts

BACKGROUND

Type 2 low-severe asthma phenotype is often a result of corticosteroid-overtreated type 2 disease owing to persistent symptoms, often unrelated to asthma and unlikely to respond to high-dose corticosteroid treatment.

OBJECTIVE

This study aimed to characterize patients with severe asthma with low eosinophil counts (<300 cells/μL) and describe their disease burden and treatment across health care settings in the United Kingdom.

METHODS

A retrospective cohort study of patients with severe asthma using linked Clinical Practice Research Datalink (CPRD) Aurum-Hospital Episode Statistics (HES) and UK Severe Asthma Registry (UKSAR) data indexed patients according to the latest blood eosinophil count (BEC). Clinical characteristics, treatment patterns, outcomes, and health care resource use were described by baseline BEC (≤150 and >150 to <300 cells/μL).

RESULTS

Analysis included 701 (CPRD-HES) and 1,546 (UKSAR) patients; 60.5% and 59.4% had BECs 150 cells/μL or less at baseline, respectively. Across BEC groups, the proportion with uncontrolled asthma (two or more exacerbations) at follow-up (12 months after the index) was 5.4% in CPRD-HES and 45.2% in UKSAR. Maintenance oral corticosteroid use remained high across BEC groups (CPRD-HES: 29.4%; UKSAR: 51.7%), symptom control remained poor (>200 μg short-acting β2 agonist or >500 μg terbutaline/d in CPRD-HES: 48.8%; median Asthma Control Questionnaire-6 score in UKSAR: 2.0 [range, 1.0-3.3]). Health care resource use was similar across BEC groups.

CONCLUSIONS

Most patients managed in primary care experienced infrequent exacerbations, whereas UKSAR patients had frequent exacerbations. Large proportions of both patient groups had poor symptom control and continued to receive high levels of maintenance oral corticosteroids, increasing the risk of corticosteroid-induced morbidity. These data highlight the need for rigorous assessment of underlying disease pathology to guide appropriate treatment.

Impact of obesity in asthma: Possible future therapies

Obesity is one of the factors associated with the severity of asthma. Obesity is associated with aggravation of the pathophysiology of asthma, including exacerbations, airway inflammation, decreased pulmonary function, and airway hyperresponsiveness. The present review addresses the characteristics of asthma with obesity, focusing especially on the heterogeneity caused by the degree of type 2 inflammation, sex differences, the onset of asthma, and race differences. To understand the severity mechanisms in asthma and obesity, such as corticosteroid resistance, fatty acids, gut microbiome, and cytokines, several basic research studies are evaluated. Finally, possible future therapies, including weight reduction, microbiome-targeted therapies, and other molecular targeted therapies are addressed. We believe that the present review will contribute to better understanding of the severity mechanisms and the establishment of novel treatments for severe asthma patients with obesity.

Characterization of Obesity in Severe Asthma in the German Asthma Net

BACKGROUND

Asthma is increasingly recognized as heterogeneous, characterized by different endotypes, with obesity not only a distinct phenotype but a risk factor for severe asthma.

OBJECTIVE

We sought to understand the associations of obesity with relevant parameters of severe asthma, including asthma control, disease burden, and lung function.

METHODS

The German Asthma Net registry is a multicenter international real-life registry capturing long-term follow-up data. This analysis included 2213 patients (52 ± 16 years, 58% female, 29% with obesity [body mass index ≥30 kg/m2], 4.2 ± 4.3 exacerbations/year). The primary analysis assessed relationships between BMI and variables through univariate tests, followed by a multiple regression model. Secondary outcomes regarded clinically relevant variables in relation to weight groups.

RESULTS

Patients with obesity were more frequently female, more likely to have depression and gastroesophageal reflux, and suffered from worse asthma control, lower quality of life, reduced static lung volumes, more pronounced hypoxemia, and higher blood neutrophil counts, all statistically significant. Blood eosinophils, exhaled nitric oxide, and total IgE were independent of obesity. In the multiple regression analysis, obesity was significantly associated with more frequent reflux and depression, reduced static lung function values, older age, poor asthma control, and long-acting muscarinic antagonist therapy, and inversely associated with bronchiectasis and nonsmoking status.

CONCLUSION

In this large, well-characterized cohort, we identified the association of obesity with a significantly higher disease burden and a similar portfolio of inflammation type 2 markers in patients with and without obesity; therefore, patients with obesity seem similarly eligible for the treatment with biologics targeting these disease endotypes.

Adult Severe Asthma Registries: A Global and Growing Inventory

Aim

The International Severe Asthma Registry (ISAR; http://isaregistries.org/) uses standardised variables to enable multi-country and adequately powered research in severe asthma. This study aims to look at the data countries within ISAR and non-ISAR countries reported collecting that enable global research that support individual country interests.

Methods

Registries were identified by online searches and approaching severe asthma experts. Participating registries provided data collection specifications or confirmed variables collected. Core variables (results from ISAR's Delphi study), steroid-related comorbidity variables, biologic safety variables (serious infection, anaphylaxis, and cancer), COVID-19 variables and additional variables (not belonging to the aforementioned categories) that registries reported collecting were summarised.

Results

Of the 37 registries identified, 26 were ISAR affiliates and 11 non-ISAR affiliates. Twenty-five ISAR-registries and 4 non-ISAR registries reported collecting >90% of the 65 core variables. Twenty-three registries reported collecting all optional steroid-related comorbidity variables. Twenty-nine registries reported collecting all optional safety variables. Ten registries reported collecting COVID-19 variables. Twenty-four registries reported collecting additional variables including data from asthma questionnaires (10 Asthma Control Questionnaire, 20 Asthma Control Test, 11 Asthma Quality of Life Questionnaire, and 4 EuroQol 5-dimension 5-level Questionnaire). Eight registries are linked to databases such as electronic medical records and national claims or disease databases.

Conclusion

Standardised data collection has enabled individual severe asthma registries to collect unified data and increase statistical power for severe asthma research irrespective of ISAR affiliations.

Real-World Experience on the Use of Mepolizumab from the Severe Asthma Registry of the German Asthma Net (MepoGAN-Study)

Purpose

The German Asthma Net (GAN) operates a Severe Asthma Registry that provides an overview of the clinical presentation and management of patients with severe asthma. Based upon data from the GAN registry, the MepoGAN study aimed to describe clinical profiles and treatment outcomes of patients who were treated with the anti-IL-5 monoclonal antibody mepolizumab (Nucala^TM) in routine practice in Germany.

Patients and Methods

The MepoGAN study is a descriptive retrospective non-interventional cohort study. Mepolizumab patients enrolled in the GAN registry were evaluated with results being described in two different data sets: Cohort 1 (n=131) started on mepolizumab when the patients entered the registry. Results were reported after 4 months of therapy. Patients in Cohort 2 (n=220) were on treatment with mepolizumab at the time of enrollment and follow-up data were collected after a further year of treatment. Outcome measures included asthma control, lung function, disease symptoms, OCS use, and exacerbations.

Results

Patients enrolled in the registry who started on mepolizumab in Cohort 1 had a mean age of 55 years, were former smokers in 51% of the cases, had a mean blood eosinophil count of 500 cells/μL, and frequently had maintenance OCS use (55%). In this real-world setting, mepolizumab therapy was associated with a clinically relevant reduction in blood eosinophils (-445.7 cells/μL), OCS use (-30%), and improvement in asthma control. Fifty-five percent (vs 10% at baseline) of the patients reported controlled or partially controlled asthma 4 months after starting therapy. In patients who were already treated with mepolizumab at registry enrollment (Cohort 2), asthma control and lung function remained stable after a further year of observation.

Conclusion

The GAN registry data confirm the effectiveness of mepolizumab in a real-world setting. Treatment benefits are maintained over time. While the asthma of patients treated in routine practice was more severe, the results observed with mepolizumab are broadly consistent with RCTs.

Epithelial cell alarmin cytokines: Frontline mediators of the asthma inflammatory response

The exposure of the airway epithelium to external stimuli such as allergens, microbes, and air pollution triggers the release of the alarmin cytokines IL-25, IL-33 and thymic stromal lymphopoietin (TSLP). IL-25, IL-33 and TSLP interact with their ligands, IL-17RA, IL1RL1 and TSLPR respectively, expressed by hematopoietic and non-hematopoietic cells including dendritic cells, ILC2 cells, endothelial cells, and fibroblasts. Alarmins play key roles in driving type 2-high, and to a lesser extent type 2-low responses, in asthma. In addition, studies in which each of these three alarmins were targeted in allergen-challenged mice showed decreased chronicity of type-2 driven disease. Consequently, ascertaining the mechanism of activity of these upstream mediators has implications for understanding the outcome of targeted therapies designed to counteract their activity and alleviate downstream type 2-high and low effector responses. Furthermore, identifying the factors which shift the balance between the elicitation of type 2-high, eosinophilic asthma and type-2 low, neutrophilic-positive/negative asthma by alarmins is essential. In support of these efforts, observations from the NAVIGATOR trial imply that targeting TSLP in patients with tezepelumab results in reduced asthma exacerbations, improved lung function and control of the disease. In this review, we will discuss the mechanisms surrounding the secretion of IL-25, IL-33, and TSLP from the airway epithelium and how this influences the allergic airway cascade. We also review in detail how alarmin-receptor/co-receptor interactions modulate downstream allergic inflammation. Current strategies which target alarmins, their efficacy and inflammatory phenotype will be discussed.

[Markers of severity and predictors of response to treatment in severe asthma]

Asthma is a multifactorial disease with complex pathophysiology. Knowledge of its immunopathology and inflammatory mechanisms is progressing and has led to the development over recent years of increasingly targeted therapeutic strategies. The objective of this review is to pinpoint the different predictive markers of asthma severity and therapeutic response. Obesity, nasal polyposis, gastroesophageal reflux disease and intolerance to aspirin have all been considered as clinical markers associated with asthma severity, as have functional markers such as bronchial obstruction, low FEV1, small daily variations in FEV1, and high FeNO. While sinonasal polyposis and allergic comorbidities are associated with better response to omalizumab, nasal polyposis or long-term systemic steroid use are associated with better response to antibodies targeting the IL5 pathway. Elevated total IgE concentrations and eosinophil counts are classic biological markers regularly found in severe asthma. Blood eosinophils are predictive biomarkers of response to anti-IgE, anti-IL5, anti-IL5R and anti-IL4R biotherapies. Dupilumab is particularly effective in a subgroup of patients with marked type 2 inflammation (long-term systemic corticosteroid therapy, eosinophilia≥150/μl or FENO>20 ppb). Chest imaging may help to identify severe patients by seeking out bronchial wall thickening and bronchial dilation. Study of the patient's environment is crucial insofar as exposure to tobacco, dust mites and molds, as well as outdoor and indoor air pollutants (cleaning products), can trigger asthma exacerbation. Wider and more systematic use of markers of severity or response to treatment could foster increasingly targeted and tailored approaches to severe asthma.

Exacerbation Profile and Risk Factors in a Type-2-Low Enriched Severe Asthma Cohort: A Clinical Trial to Assess Asthma Exacerbation Phenotypes

Rationale: The past 25 years have seen huge progress in understanding of the pathobiology of type-2 (T2) asthma, identification of measurable biomarkers, and the emergence of novel monoclonal antibody treatments. Although present in a minority of patients with severe asthma, very little is known about the mechanisms underlying T2-low asthma, making it a significant unmet need in asthma research. Objectives: The objective of this study was to explore the differences between study exacerbators and nonexacerbators, to describe physiological changes at exacerbation in those who are T2^HIGH and T2^LOW at the time of exacerbation, and to evaluate the stability of inflammatory phenotypes when stable and at exacerbation. Methods: Exacerbation assessment was a prespecified secondary analysis of data from a 48-week, multicenter, randomized controlled clinical study comparing the use of biomarkers and symptoms to adjust steroid treatment in a T2-low severe asthma-enriched cohort. Participants were phenotyped as T2^LOW (fractional exhaled nitric oxide ⩽ 20 ppb and blood eosinophil count ⩽ 150 cells/µl) or T2^HIGH (fractional exhaled nitric oxide > 20 or blood eosinophil count > 150) at study enrollment and at each exacerbation. Here, we report the findings of the exacerbation analyses, including comparison of exacerbators and nonexacerbators, the physiological changes at exacerbation in those who had evidence of T2 biology at exacerbation versus those that did not, and the stability of inflammatory phenotypes when stable and at exacerbation. Measurements and Main Results: Of the 301 participants, 60.8% (183) had one or more self-reported exacerbations (total of 390). Exacerbators were more likely to be female, have a higher body mass index, and have more exacerbations requiring oral corticosteroid and unscheduled primary care attendances for exacerbations. At enrollment, 23.6% (71) were T2^LOW and 76.4% (230) T2^HIGH. The T2^LOW group had more asthma primary care attendances, were more likely to have a previous admission to HDU (high dependency unit)/ICU and to be receiving maintenance oral corticosteroids. At exacerbation, the T2^LOW events were indistinguishable from T2^HIGH exacerbations in terms of lung function (mean fall in T2^LOW FEV_1, 200 [400] ml vs. T2^HIGH 200 [300] ml; P = 0.93) and symptom increase (ACQ5: T2^LOW, 1.4 [0.8] vs. T2^HIGH, 1.3 [0.8]; P = 0.72), with no increase in T2 biomarkers from stable to exacerbation state in the T2^LOW exacerbations. The inflammatory phenotype within individual patients was dynamic; inflammatory phenotype at study entry did not have a significant association with exacerbation phenotype. Conclusions: Asthma exacerbations demonstrating a T2^LOW phenotype were physiologically and symptomatically similar to T2^HIGH exacerbations. T2^LOW asthma was an unstable phenotype, suggesting that exacerbation phenotyping should occur at the time of exacerbation. The clinically significant exacerbations in participants without evidence of T2 biology at the time of exacerbation highlight the unmet and pressing need to further understand the mechanisms at play in non-T2 asthma. Clinical trial registered with www.clinicaltrials.gov (NCT02717689).

Documento de consenso de asma grave en adultos. Actualización 2022

Severe asthma is a heterogeneous syndrome with several clinical variants and often represents a complex disease requiring a specialized and multidisciplinary approach, as well as the use of multiple drugs. The prevalence of severe asthma varies from one country to another, and it is estimated that 50% of these patients present a poor control of their disease. For the best management of the patient, it is necessary a correct diagnosis, an adequate follow-up and undoubtedly to offer the best available treatment, including biologic treatments with monoclonal antibodies. With this objective, this consensus process was born, which began in its first version in 2018, whose goal is to offer the patient the best possible management of their disease in order to minimize their symptomatology. For this 2020 consensus update, a literature review was conducted by the authors. Subsequently, through a two-round interactive Delphi process, a broad panel of asthma experts from SEPAR and the regional pulmonology societies proposed the recommendations and conclusions contained in this document.

Should we apply a treatable traits approach to asthma care?

OBJECTIVE

To explore the evidence for adopting a "treatable traits" approach to asthma management.

DATA SOURCES

PubMed, Medline, and Google Scholar.

STUDY SELECTIONS

The above-mentioned databases were searched for randomized, controlled phase III or IV trials of adults containing the word "asthma" in the title published in the previous 10 years and for all articles containing the title words "treatable AND trait(s)," "asthma AND biomarker(s) OR smoking OR obesity OR laryngeal OR management" published within the previous 5 years. Articles were excluded if they were not published in English. Our search identified 257 articles for consideration. We also manually searched the reference lists of studies identified and searched the websites of the British Thoracic Society, European Respiratory Society, National Institute for Health and Care Excellence, and Global Initiative for Asthma for specific guidance related to asthma management.

RESULTS

The "treatable traits" are described within 3 domains of pulmonary, extrapulmonary, or behavioral and lifestyle traits. We consider whether treatment should be targeted toward these traits where they are present in asthma patients, based on currently available evidence, rather than increasing treatment in response to symptoms in line with current step-up, step-down asthma management guidelines.

CONCLUSION

We advocate that a treatable traits approach should be applied more broadly to the assessment and management of inadequately controlled asthma, rather than a step-up, step-down approach based on patient symptoms. This approach should be focused on the 2 treatable pulmonary traits of T_H2 inflammation and airflow obstruction along with smoking cessation, in the first instance.

Just breathe: a review of sex and gender in chronic lung disease

Chronic lung diseases are the third leading cause of death worldwide and are increasing in prevalence over time. Although much of our traditional understanding of health and disease is derived from study of the male of the species - be it animal or human - there is increasing evidence that sex and gender contribute to differences in disease risk, prevalence, presentation, severity, treatment approach, response and outcomes. Chronic obstructive pulmonary disease, asthma and bronchiectasis represent the most prevalent and studied chronic lung diseases and have key sex- and gender-based differences which are critical to consider and incorporate into clinical and research approaches. Mechanistic differences present opportunities for therapeutic development whereas behavioural and clinical differences on the part of patients and providers present opportunities for greater education and understanding at multiple levels. In this review, we seek to summarise the sex- and gender-based differences in key chronic lung diseases and outline the clinical and research implications for stakeholders.

Gastroesophageal reflux disease and asthma exacerbation: A systematic review and meta-analysis

BACKGROUND

Gastroesophageal reflux disease (GORD) is highly prevalent and often coexists with asthma exacerbation. Divergent findings about the association between the two diseases were reported. We conducted a systematic review and meta-analysis to determine whether there exists an association between GORD and asthma.

METHODS

We searched MEDLINE, EMBASE, and other databases and then performed a manual search, to identify eligible studies. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using fixed- and random-effect models. We evaluated the quality of included studies, explored heterogeneity between studies, undertook subgroup analyses, assessed publication bias, and performed sensitivity analyses.

RESULTS

We identified 32 eligible studies, conducted in 14 countries and including a total of 1,612,361 patients of all ages. Overall, GORD shows a weak association with asthma exacerbation (OR = 1.27; 95% CI 1.18-1.35). This association was observed in cohort, case-control, and cross-sectional designs and in European as well as non-European populations. Subgroup analyses show that GORD is associated with frequent asthma exacerbations (≥3 exacerbations, OR = 1.59; 95% CI 1.13-2.24) and with exacerbations needing oral corticosteroid therapy (OR = 1.24; 95% CI 1.09-1.41). GORD pediatric patients are at higher odds of asthma exacerbation than adults. We did not detect any evidence of publication bias and the association between GORD and asthma exacerbation held in all undertaken sensitivity analyses.

CONCLUSIONS

Gastroesophageal reflux disease and asthma exacerbation are weakly associated.