Identifying asthma triggers

Tezepelumab reduces exacerbations across all seasons in patients with severe, uncontrolled asthma (NAVIGATOR)

BACKGROUND

Asthma exacerbation frequencies vary throughout the year owing to seasonal triggers. Tezepelumab is a human monoclonal antibody that targets thymic stromal lymphopoietin. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab significantly reduced the annualized asthma exacerbation rate (AAER) vs placebo in patients with severe, uncontrolled asthma.

OBJECTIVE

To evaluate the effect of tezepelumab on asthma exacerbations across all seasons in NAVIGATOR patients (post hoc).

METHODS

NAVIGATOR was a multicenter, randomized, double-blind, placebo-controlled study. Patients (12-80 years old) were randomized 1:1 to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. AAER over 52 weeks was assessed by season. Data from patients in the Southern Hemisphere were transformed to align with Northern Hemisphere seasons.

RESULTS

Tezepelumab reduced the AAER vs placebo by 63% (95% confidence interval [CI], 52-72) in winter, 46% (95% CI, 26-61) in spring, 62% (95% CI, 48-73) in summer, and 54% (95% CI, 41-64) in fall. In matched climates, during the spring allergy season (March 1 to June 15) and ragweed allergy season (September), tezepelumab reduced the AAER vs placebo in patients with seasonal allergy by 59% (95% CI, 29-77) and 70% (95% CI, 33-87), respectively. In patients with perennial allergy and in those with seasonal allergy, tezepelumab reduced the AAER vs placebo across all seasons.

CONCLUSION

Tezepelumab reduced exacerbations across all seasons vs placebo in patients with severe, uncontrolled asthma, including patients with seasonal and perennial allergies. These data further support the efficacy of tezepelumab in a broad population of patients with severe, uncontrolled asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03347279 (https://clinicaltrials.gov/ct2/show/NCT03347279).

Number of patient-reported asthma triggers predicts uncontrolled disease among specialist-treated patients with severe asthma

BACKGROUND

Patients with severe asthma (SA) experience a high disease burden, often precipitated by exposure to disease triggers.

OBJECTIVE

To evaluate the prevalence and effects of patient-reported triggers on asthma disease burden in a cohort of subspecialist-treated patients with SA in the United States.

METHODS

CHRONICLE is an observational study of adults with SA receiving biologics or maintenance systemic corticosteroids or whose disease is uncontrolled on high-dosage inhaled corticosteroids and additional controllers. Data were analyzed for patients enrolled between February 2018 and February 2021. This analysis evaluated patient-reported triggers from a 17-category survey and associations with multiple measures of disease burden.

RESULTS

Among 2793 enrolled patients, 1434 (51%) completed the trigger questionnaire. The median trigger number per patient was 8 (interquartile range, 5-10). The most frequent triggers were weather or air changes, viral infections, seasonal allergies, perennial allergies, and exercise. Patients reporting more triggers experienced more poorly controlled disease, worse quality of life, and reduced work productivity. The annualized rates of exacerbations and asthma hospitalizations increased by 7% and 17%, respectively, for each additional trigger (both P < .001). For all measures, trigger number was a stronger predictor of disease burden than blood eosinophil count.

CONCLUSION

Among US specialist-treated patients with SA, asthma trigger number was positively and significantly associated with greater uncontrolled disease burden across multiple measures, which highlights the importance of understanding patient-reported triggers in SA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03373045.

Serum allergen-specific IgE reactivity: is there an association with clinical severity and airway eosinophilia in asthmatic cats?

OBJECTIVES

The aim of this study was to evaluate the results of serum allergen-specific IgE testing in cats with a clinical diagnosis of asthma and to determine if the number of allergens with positive IgE reactivity and magnitude of positive IgE responses would be associated with the severity of clinical signs or airway eosinophilia.

METHODS

Medical records from 2008 to 2018 were retrospectively reviewed. Inclusion required a diagnosis of feline asthma based on consistent clinicopathologic features and bronchoalveolar lavage (BAL) cytology with >10% eosinophils; additionally, cats needed to have the results of serum allergen-specific IgE tests.

RESULTS

Eighteen cases satisfied the inclusion criteria. Median age was 5 years and the most common presenting clinical sign was cough (n = 10/18). Most cats lived exclusively indoors (n = 13/18). The median percentage of BAL eosinophils was 47%. Serum allergen-specific IgE testing supported an underlying allergic etiology in 14/18 (78%) cats, with all but one having polysensitization. The severity of clinical signs and magnitude of airway eosinophilia did not correlate with the degree of positive IgE reactivity.

CONCLUSIONS AND RELEVANCE

This study identified a strong association between the identification of allergen-specific IgE and cats with asthma, and the majority of these cats were polysensitized. However, larger numbers of allergens with positive IgE reactivity or magnitude of IgE reactivity were not significantly associated with clinical severity or airway eosinophilia. Knowledge of positive allergen-specific IgE results could guide allergen avoidance, regardless of the magnitude of IgE reactivity.

Regional Disparity in Asthma Prevalence and Distribution of Asthma Education Programs in Texas

Objectives

To identify the distribution of asthma education programs that are currently active in Texas and examine whether there is a geographical disparity between asthma prevalence and locations of asthma education programs in the Public Health Regions (PHRs) of Texas.

Methods

The data for adult asthma prevalence in PHRs was obtained from the Texas Department of State and Health Services (DSHS) 2015 Texas Behavioral Risk Factor Surveillance System (BRFSS) Public Use Data File. The Geographic Information System (GIS) program was used to show the distribution of asthma education programs and visually identify the isolated areas for asthma education programs on the maps. To examine the areas covered by the asthma education programs, we illustrated 50 miles and 70 miles of buffer zones from each program by proximity (multiple ring buffer) functions in GIS.

Results

We identified that 27 asthma education programs are active in Texas as of July 2019. The analysis showed that PHRs 1, 2, and 7 had the highest rate of asthma prevalence but had fewer asthma education programs. Also, the distribution of asthma education programs is concentrated around major cities, leading to a regional imbalance between asthma prevalence and locations of asthma education programs. The central and western areas of Texas proved to be marginalized areas for asthma education programs, particularly PHRs 2 and 9 because they may not be covered by the buffer zones of 70 miles from any asthma education programs. Discussion. This study revealed the marginalized regions in Texas lacking asthma education programs. The findings could help policymakers and health care professionals enhance opportunities to develop asthma education programs using different venues in isolated areas and prioritize these regions, for funds, to establish new asthma education programs.

The Benefits and Challenges of Managing Asthma in Hispanic Families in South Texas: A Mixed-Methods Study

Background

Understanding the experience of Hispanic parents of children diagnosed with asthma can be useful in the delivery of effective and meaningful asthma education. In order to assess the needs of Hispanic families with asthmatic children in South Texas, investigators utilized a combination of qualitative and quantitative research methods.

Objectives

This study aimed (1) to assess the impact of asthma in the quality of life of Hispanic children and their families and (2) to identify barriers and challenges to asthma management as perceived by parents of children diagnosed with asthma.

Methods

A mixed-methods study included a quality-of-life survey and focus group discussions. The Children’s Health Survey for Asthma (CHSA) was completed by 90 parents of children with asthma. Three focus groups were conducted with 15 low-income, Hispanic parents of asthmatic children to assess their needs and experience in managing the disease.

Results

Results from the CHSA showed that asthma significantly affects the quality of life of children with asthma and their families, particularly the emotional dimensions and the child’s physical health. Fifty-three percent of the children had visited the emergency room, and 51% had been hospitalized due to asthma. One out of five parents had missed work, and 27% of children had missed school in the past 2 weeks due to the child’s asthma. In the focus group discussions, the key themes emerging included lack of asthma knowledge, the burden of disease for asthmatic children and their families, and the importance of asthma education and self-management behaviors for asthma control.

Conclusion

One of the main challenges faced by Hispanic families with asthmatic children is the lack of asthma-related knowledge to help understand and control their children’s disease. Lack of knowledge and self-management skills lead to significant stress and anxiety among children with asthma and their parents. Results highlight that while asthma has an effect on the quality of life of children and their families, particularly on the emotional health domain, a wide dissemination of asthma management education in different settings might help prevent asthma attacks and improve symptom control among those suffering from this disease along the US–Mexico border.

Novel Therapies to Inhibit Mucus Synthesis and Secretion in Airway Hypersecretory Diseases

BACKGROUND

In asthma and chronic obstructive pulmonary disease (COPD), airway mucus hypersecretion contributes to impaired mucociliary clearance, mucostasis and, potentially, the development of mucus plugging of the airways.

SUMMARY

Excess mucus production can be targeted via therapies that focus on inhibition mucin synthesis, via reducing expression of mucin (MUC) genes, and/or inhibition of mucin secretion into the airways.

KEY MESSAGES

This review discusses a number of therapeutic approaches to reduce airway mucus in asthma and COPD, including the use of synthetic and natural products. In particular, it highlights areas where clinical trials of inhibitors of particular target molecules are lacking. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors are an example of a targeted therapy that has been researched to reduce mucus synthesis, as have inhibitors of EGFR's downstream signalling pathways, for example, mitogen-activated protein kinase-13 and hypoxia inducible factor-1. However, their efficacy and safety profiles are currently not up to the mark. There is clinical potential in Bio-11006, which reduces mucus secretion via the inhibition of myristoylated alanine-rich C-kinase substrate and is currently in Phase IIb trial.

Impacting Environmental and Public Health through the Use of Dual Targeted and Tailored Asthma Educational Interventions

Home-based asthma environmental education for parents of asthmatic children is needed since many health professionals lack the time to offer it. However, developing targeted and tailored education is important in order to address the individual needs of participants. This nonrandomized longitudinal study examined knowledge on asthma with an Asthma and Healthy Homes educational intervention training offered to parents of children from low income families who reside in the Rio Grande Valley of Texas. Eighty-nine parents received the training and pre- and posttest surveys were used to measure knowledge outcomes. A standardized assessment on asthma triggers was used to identify the different triggers each child was exposed to, and a follow-up survey was conducted 6 months after the educational intervention to identify how many parents reported household and behavior changes as a result of the training. Results showed significant changes in behavior by participants as a result of the training received. This study suggests that these behavioral changes are attributed to the dual "targeted" and "tailored" educational interventions delivered to parents which resulted in a greater understanding of how to manage asthma by eliminating asthma triggers in their respective homes.

Asthma Bronchiale and Exercise-Induced Bronchoconstriction

Exercising regularly has a wide range of beneficial health effects; in particular, it has been well documented to help in the management of chronic illnesses including asthma. However, in some individuals, exertion can also trigger an exacerbation of asthmatic episodes and subsequent acute attacks of breathlessness, coughing, tightness of the chest and wheezing. This physiological process is called exercise-induced bronchoconstriction (EIB) whereby post-exercise forced expiratory volume in 1 s is reduced by 10-15% from baseline. While EIB is highly prevalent in asthmatics and presents with similar respiratory symptoms, asthma and EIB are not mutually exclusive. The aim of this review is to present a broad overview of both conditions in order to enhance the understanding of the similarities and differences distinguishing them as two separate entities. The pathophysiology and mechanisms underlying asthma are well described with research now focussing on defining phenotypes for targeted management strategies. Conversely, the mechanistic understanding of EIB remains largely under-described. Diagnostic pathways for both are established and similar, as are pharmacologic and non-pharmacologic treatments and management approaches, which have enhanced success with early detection. Given the potential for exacerbation of asthma, exercise avoidance is common but counterproductive as current evidence indicates that it is well tolerated and improves quality of life. Literature supporting the benefit of exercise for EIB sufferers is at present favourable, yet extremely limited; therefore, future research should be directed in this area as well as towards further developing the understanding of the pathophysiology and mechanisms underpinning both EIB and asthma.