Smoking affects response to inhaled corticosteroids or leukotriene receptor antagonists in asthma

The role of mitochondria in eosinophil function: implications for severe asthma pathogenesis

Mitochondria are key metabolic hubs involved in cellular energy production and biosynthesis. ATP is generated primarily by glucose and fatty acid oxidation through the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) in the mitochondria. During OXPHOS there is also production of reactive oxygen species (ROS), which are involved in the regulation of cellular function. Mitochondria are also central in the regulating cell survival and death, particularly in the intrinsic apoptosis pathway. Severe asthma is a heterogeneous disease driven by various immune mechanisms. Severe eosinophilic asthma entails a type 2 inflammatory response and peripheral and lung eosinophilia, associated with severe airflow obstruction, frequent exacerbations and poor response to treatment. Mitochondrial dysfunction and altered metabolism have been observed in airway epithelial and smooth muscle cells from patients with asthma. However, the role of mitochondria in the development of eosinophilia and eosinophil-mediated inflammation in severe asthma is unknown. In this review, we discuss the currently limited literature on the role of mitochondria in eosinophil function and how it is regulated by asthma-relevant cytokines, including interleukin (IL)-5 and granulocyte-macrophage colony-stimulating factor (GM-CSF), as well as by corticosteroid drugs. Moreover, we summarise the evidence on the role of mitochondria in the regulation of eosinophils apoptosis and eosinophil extracellular trap formation. Finally, we discuss the possible role of altered mitochondrial function in eosinophil dysfunction in severe asthma and suggest possible research avenues in order to better understand their role in disease pathogenesis, and identify novel therapeutic targets.

Lipid mediators of inhalation exposure-induced pulmonary toxicity and inflammation

Many inhalation exposures induce pulmonary inflammation contributing to disease progression. Inflammatory processes are actively regulated via mediators including bioactive lipids. Bioactive lipids are potent signaling molecules involved in both pro-inflammatory and resolution processes through receptor interactions. The formation and clearance of lipid signaling mediators are controlled by multiple metabolic enzymes. An imbalance of these lipids can result in exacerbated and sustained inflammatory processes which may result in pulmonary damage and disease. Dysregulation of pulmonary bioactive lipids contribute to inflammation and pulmonary toxicity following exposures. For example, inhalation of cigarette smoke induces activation of pro-inflammatory bioactive lipids such as sphingolipids, and ceramides contributing to chronic obstructive pulmonary disease. Additionally, exposure to silver nanoparticles causes dysregulation of inflammatory resolution lipids. As inflammation is a common consequence resulting from inhaled exposures and a component of numerous diseases it represents a broadly applicable target for therapeutic intervention. With new appreciation for bioactive lipids, technological advances to reliably identify and quantify lipids have occurred. In this review, we will summarize, integrate, and discuss findings from recent studies investigating the impact of inhaled exposures on pro-inflammatory and resolution lipids within the lung and their contribution to disease. Throughout the review current knowledge gaps in our understanding of bioactive lipids and their contribution to pulmonary effects of inhaled exposures will be presented. New methods being employed to detect and quantify disruption of pulmonary lipid levels following inhalation exposures will be highlighted. Lastly, we will describe how lipid dysregulation could potentially be addressed by therapeutic strategies to address inflammation.

How Does Mild Asthma Differ Phenotypically from Difficult-to-Treat Asthma?

Background

Despite most of the asthma population having mild disease, the mild asthma phenotype is poorly understood. Here, we aim to address this gap in knowledge by extensively characterising the mild asthma phenotype and comparing this with difficult-to-treat asthma.

Methods

We assessed two real-world adult cohorts from the South of England using an identical methodology: the Wessex AsThma CoHort of difficult asthma (WATCH) (n=498) and a mild asthma cohort from the comparator arm of the Epigenetics Of Severe Asthma (EOSA) study (n=67). Data acquisition included detailed clinical, health and disease-related questionnaires, anthropometry, allergy and lung function testing, plus biological samples (blood and sputum) in a subset.

Results

Mild asthma is predominantly early-onset and is associated with type-2 (T2) inflammation (atopy, raised fractional exhaled nitric oxide (FeNO), blood/sputum eosinophilia) plus preserved lung function. A high prevalence of comorbidities and multimorbidity was observed in mild asthma, particularly depression (58.2%) and anxiety (56.7%). In comparison to difficult asthma, mild disease showed similar female predominance (>60%), T2-high inflammation and atopy prevalence, but lower peripheral blood/airway neutrophil counts and preserved lung function. Mild asthma was also associated with a greater prevalence of current smokers (20.9%). A multi-component T2-high inflammatory measure was comparable between the cohorts; T2-high status 88.1% in mild asthma and 93.5% in difficult asthma.

Conclusion

Phenotypic characterisation of mild asthma identified early-onset disease with high prevalence of current smokers, T2-high inflammation and significant multimorbidity burden. Early comprehensive assessment of mild asthma patients could help prevent potential later progression to more complex severe disease.

Frequency and characteristics of asthma in smokers attending smoking cessation units in Spain

INTRODUCTION

The interaction between smoking and asthma impairs lung function and increases airflow obstruction severity. The identification of smoking patterns in smokers with and without asthma is crucial to provide the best care strategies. The aims of this study are to estimate asthma frequency, describe asthma features, and characterize smoking in smokers attending smoking cessation units.

MATERIAL AND METHODS

We carried out a cross-sectional study in five smoking cessation units with different geographical distribution to estimate asthma frequency in smokers, characterize asthma features in smokers, as well as smoking in asthmatic smokers.

RESULTS

Asthma frequency among smokers was 18.6%. Asthmatic smokers presented high passive exposure, low smoking self-efficacy and will to quit smoking, as well as a high exacerbation frequency, severe symptoms, and frequent use of long-acting beta agonists, inhaled steroids, and short-acting beta agonists.

DISCUSSION

Smokers with asthma constitute a high-risk group with worsened evolution of pulmonary involvement. All smokers should be regularly screened for asthma. Effective smoking cessation strategies should be proposed to smokers with asthma in order to reverse the harmful effects of smoking on the airway, together with a comprehensive and integral approach.

Dupilumab Efficacy in Patients with Type 2 Asthma with and without Elevated Blood Neutrophils

Introduction

Elevated neutrophil counts in blood, sputum, or lung have been associated with poor clinical outcomes and more severe disease in patients with type 2 asthma. In the phase 3 LIBERTY ASTHMA QUEST (NCT02414854), add-on dupilumab 200 and 300 mg every 2 weeks compared with matched placebo significantly reduced severe asthma exacerbations and improved forced expiratory volume in 1 s (FEV1) in patients with uncontrolled, moderate-to-severe asthma. This post hoc analysis explored the efficacy of dupilumab in patients with type 2 asthma enrolled in QUEST with or without elevated blood neutrophil counts.

Methods

Annualized severe exacerbation rates during the 52-week treatment period and least-squares mean change from baseline in FEV1 over time were evaluated for patients with elevated type 2 biomarkers at baseline (blood eosinophils ≥ 150 cells/µL or fractional exhaled nitric oxide (FeNO) ≥ 20 ppb; and eosinophils ≥ 300 cells/µL or FeNO ≥ 50 ppb) and low (<4,000 cells/µL) or high (≥4,000 cells/µL) neutrophil counts.

Results

Dupilumab significantly reduced annualized severe exacerbation rates compared with placebo during the 52-week treatment period in patients with elevated type 2 biomarkers, irrespective of baseline neutrophil count (P < 0.0001 for all comparisons). Significant improvements in FEV1 versus placebo were observed as early as Week 2 and over the 52-week treatment period, irrespective of baseline neutrophil count (P < 0.001 for all comparisons). Safety findings were similar across all subgroups, regardless of neutrophil counts at baseline.

Conclusions

Dupilumab treatment significantly reduced annualized severe exacerbation rates and improved lung function in patients with uncontrolled, moderate-to-severe, type 2 asthma, irrespective of baseline blood neutrophil count. This trial is registered with NCT02414854.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Mild asthma: Lessons learned and remaining questions

Patients living with mild disease represent the largest proportion of asthma patients. There are significant challenges in proposing a definition that would best describe these patients, while also accurately identifying at-risk individuals. Current literature suggests considerable inflammatory and clinical heterogeneity within this group. Research has shown that these patients are at risk of poor control, exacerbations, lung function decline, and death. Despite conflicting data on its prevalence, eosinophilic inflammation appears to be a predictor of poorer outcomes in mild asthma. There is an immediate need to better understand phenotypic clusters in mild asthma. It is also important to understand factors that influence disease progression and remission, as it is evident that both vary in mild asthma. Guided by robust literature that supports inhaled corticosteroid-based strategies over short-acting beta-agonist (SABA) reliant regimens, the management of these patients has evolved considerably. Unfortunately, SABA use remains high in clinical practice despite strong advocacy from the Global Initiative for Asthma. Future mild asthma research should explore the role of biomarkers, develop prediction tools based on composite risk scores, and explore targeted therapies at least for at-risk individuals.

Questions in Mild Asthma: An Official American Thoracic Society Research Statement

Background: Patients with mild asthma are believed to represent the majority of patients with asthma. Disease-associated risks such as exacerbations, lung function decline, and death have been understudied in this patient population. There have been no prior efforts from major societies to describe research needs in mild asthma. Methods: A multidisciplinary, diverse group of 24 international experts reviewed the literature, identified knowledge gaps, and provided research recommendations relating to mild asthma definition, pathophysiology, and management across all age groups. Research needs were also investigated from a patient perspective, generated in conjunction with patients with asthma, caregivers, and stakeholders. Of note, this project is not a systematic review of the evidence and is not a clinical practice guideline. Results: There are multiple unmet needs in research on mild asthma driven by large knowledge gaps in all areas. Specifically, there is an immediate need for a robust mild asthma definition and an improved understanding of its pathophysiology and management strategies across all age groups. Future research must factor in patient perspectives. Conclusions: Despite significant advances in severe asthma, there remain innumerable research areas requiring urgent attention in mild asthma. An important first step is to determine a better definition that will accurately reflect the heterogeneity and risks noted in this group. This research statement highlights the topics of research that are of the highest priority. Furthermore, it firmly advocates the need for engagement with patient groups and for more support for research in this field.

T2-Low Asthma: A Discussed but Still Orphan Disease

Asthma affects 10% of the worldwide population; about 5% of cases are severe with the need for target therapies such as biologics. All the biologics approved for asthma hit the T2 pathway of inflammation. T2-high asthma is classified as allergic and non-allergic, whereas T2-low asthma can be further defined as paucigranulocytic asthma, Type 1 and Type-17 inflammation and the neutrophilic form that accounts for 20-30% of all patients with asthma. Neutrophilic asthma's prevalence is even higher in patients with severe or refractory asthma. We searched Medline and PubMed archives from the past ten years for articles with the subsequent titles: "neutrophilic asthma", "non-type 2 asthma" and "paucigranulocytic asthma". We identified 177 articles; 49 were considered relevant by the title and 33 by the reading of the abstract. Most of these articles are reviews (n = 19); only 6 are clinical trials. No study identified an effective treatment. We used the literature reported by these articles to search for further biologic treatments that target pathways different from T2. We identified 177 articles, 93 of which were considered relevant for the review and included in the present article. In conclusion, T2-low asthma remains poorly investigated in terms of biomarkers, especially as a therapeutic orphan disease.

The ICS/Formoterol Reliever Therapy Regimen in Asthma: A Review

The Global Initiative for Asthma recommends that low-dose inhaled corticosteroid (ICS)/formoterol be preferred to short-acting beta₂-agonists as reliever therapy in adolescents and adults with asthma, across the range of asthma severity. This recommendation represents the most fundamental change in asthma management for many decades. In this commentary, we review the rationale for combination ICS/formoterol therapy, the evidence on which this recommendation has been made, the limitations in the evidence, the practical issues relevant to the implementation of ICS/formoterol reliever-based regimens in clinical practice, and the emerging evidence for the efficacy and safety of combination ICS/salbutamol reliever therapy regimens.

Association between tobacco product use and asthma among US adults from the Population Assessment of Tobacco and Health (PATH) Study waves 2-4

BACKGROUND

Research on cigarettes and adult asthma offers mixed findings, perhaps due to overlap with chronic obstructive pulmonary disease (COPD) and inadequate adjustment for other smoke exposures. Associations between other tobacco products, including e-cigarettes, and asthma are also understudied.

RESEARCH QUESTION

Using Population Assessment of Tobacco and Health Study waves 2-4 (2014/2015-2016/2017) data, we assessed the relation between tobacco product use and asthma in persons unlikely to have COPD.

STUDY DESIGN AND METHODS

Prospective study of 10 267 adults aged 18-39 years without COPD diagnoses. Past-month tobacco use at wave 2 was modelled first as combustible versus non-combustible use and second as specific product categories (former, cigarettes, e-cigarettes, cigars, hookah, smokeless tobacco). Outcomes included lifetime asthma prevalence at wave 2, incidence (waves 3 and 4) and Asthma Control Test score (lower=worse). Multivariable regressions adjusted for predictors of asthma, including other smoke exposures: cigarette pack-years, secondhand smoke and marijuana use. Sensitivity analyses examined findings when persons >39 years and those with both COPD and asthma were added, and when smoke exposure adjustments were removed.

RESULTS

No product, including cigarettes and e-cigarettes, was associated with prevalence or incidence of asthma. Among people with asthma at wave 2, combustible tobacco (beta=-0.86, 95% CI (-1.32 to -0.39)) and cigarettes (beta=-1.14, 95% CI (-1.66 to -0.62)) were associated with worse asthma control. No tobacco product was associated with asthma control over time. In sensitivity analyses, tobacco use became associated with incident asthma as adults >39 years and those with asthma+COPD were added, and as adjustments for other smoke exposures were omitted.

INTERPRETATION

Although cigarette use was associated with worse asthma control, there were no longitudinal associations between combustible tobacco or e-cigarette use and new onset or worsening asthma in these preliminary analyses. Research on tobacco and asthma should exclude COPD and adjust for smoking history and other smoke exposures.

Long-term effect of asthma on the development of obesity among adults: an international cohort study, ECRHS

INTRODUCTION

Obesity is a known risk factor for asthma. Although some evidence showed asthma causing obesity in children, the link between asthma and obesity has not been investigated in adults.

METHODS

We used data from the European Community Respiratory Health Survey (ECRHS), a cohort study in 11 European countries and Australia in 3 waves between 1990 and 2014, at intervals of approximately 10 years. We considered two study periods: from ECRHS I (t) to ECRHS II (t+1), and from ECRHS II (t) to ECRHS III (t+1). We excluded obese (body mass index≥30 kg/m²) individuals at visit t. The relative risk (RR) of obesity at t+1 associated with asthma at t was estimated by multivariable modified Poisson regression (lag) with repeated measurements. Additionally, we examined the association of atopy and asthma medication on the development of obesity.

RESULTS

We included 7576 participants in the period ECRHS I-II (51.5% female, mean (SD) age of 34 (7) years) and 4976 in ECRHS II-III (51.3% female, 42 (8) years). 9% of participants became obese in ECRHS I-II and 15% in ECRHS II-III. The risk of developing obesity was higher among asthmatics than non-asthmatics (RR 1.22, 95% CI 1.07 to 1.38), and particularly higher among non-atopic than atopic (1.47; 1.17 to 1.86 vs 1.04; 0.86 to 1.27), those with longer disease duration (1.32; 1.10 to 1.59 in >20 years vs 1.12; 0.87 to 1.43 in ≤20 years) and those on oral corticosteroids (1.99; 1.26 to 3.15 vs 1.15; 1.03 to 1.28). Physical activity was not a mediator of this association.

CONCLUSION

This is the first study showing that adult asthmatics have a higher risk of developing obesity than non-asthmatics, particularly those non-atopic, of longer disease duration or on oral corticosteroids.

Association between vitamin A and asthma: A meta-analysis with trial sequential analysis

Objective: To explore the association between vitamin A (vit A) status and risk of asthma. Methods: PubMed, Web of Science, Embase and the Cochrane Library were electronically searched to identify related studies that reported the association between vit A status and asthma. All databases were searched from inception to November 2022. Two reviewers independently screened literature, extracted data, and assessed risk bias of included studies. Meta-analysis was performed on R software Version 4.1.2 and STATA Version 12.0. Results: A total of 19 observational studies were included. A pooled analysis showed that the serum vit A concentrations in patients with asthma was lower than that in healthy controls (standard mean difference (SMD)= -2.479, 95% confidence interval (CI): -3.719, -.239, 95% prediction interval (PI): -7.510, 2.552), and relatively higher vit A intake in pregnancy was associated with an increased risk of asthma at age 7 years (risk ratio (RR)= 1.181, 95% CI: 1.048, 1.331). No significant correlation was observed between serum vit A levels or vit A intake and the risk of asthma. Conclusion: Our meta-analysis confirms that serum vit A levels are lower in patients with asthma than in healthy controls. Relatively higher vit A intake during pregnancy is associated with an increased risk of asthma at age 7 years. There is no significant correlation between vit A intake and asthma risk in children, nor between serum vit A levels and asthma risk. The effect of vit A may depend on age or developmental stage, diet and genetics. Therefore, further studies are needed to explore the association of vit A and asthma. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/CRD42022358930, identifier CRD42022358930.

Spatial, temporal and demographic patterns in asthma mortality in China: A systematic analysis from 2014 to 2020

Background

Asthma is an important contributor to the burden of non-communicable diseases in China. Understanding spatial, temporal, and demographic patterns in asthma mortality is relevant to the design and implementation of targeted interventions.

Methods

This study collected information on asthma deaths occurring across 605 disease surveillance points (DSPs) as recorded in the population-based national mortality surveillance system (NMSS) of China. Asthma was defined according to the International Classification of Diseases, 10th Revision code J45-J46. Estimates of age-standardized mortality rates and total national asthma deaths were calculated based on yearly population data. Statistical analysis was performed to investigate the influence of various factors on asthma mortality.

Results

Between 2014 and 2020, a total of 40 116 asthma deaths occurred in DSPs. Standardized asthma mortality per 100 000 people decreased from 1.79 (95% CI: 1.74-1.83) in 2014 to 1.07 (95% CI: 1.03-1.10) in 2020 in China. In 2020, the overall asthma mortality rate was higher for male patients than for female patients, and asthma mortality rates increased substantially with age. Age-standardized asthma mortality per 100,000 people exhibited significant geographic variation, ranging from 0.93 (95% CI: 0.89-0.98) in Eastern China to 1.04 (95% CI: 0.98-1.10) in Central China and 1.37 (95% CI: 1.29-1.45) in Western China in 2020. Asthma mortality in urban areas appeared to be higher than in rural areas. Socioeconomic factors, including gross domestic product per capita and density of hospital beds per 10,000 population, may be related to asthma mortality. Male asthma patients who lived in rural areas and were aged 65 years and above were generally at high risk of asthma-related mortality.

Conclusions

This study found a spatial and temporal trend for a reduction in asthma deaths over seven years in China; however, there remain important sociodemographic groups that have not secured the same decrease in mortality rates.

Trial registration

This was a purely observational study and thus registration was not required.

Heterogeneity of Treatment Response to Asthma

The definition of asthma has evolved over the years with significant heterogeneity of the disease increasingly recognized. Complex gene and environment interactions result in different pheno-endotypes of asthma that respond differently to the same treatment. Multiple studies have revealed pharmacogenomic and endophenotypic factors that predict treatment response to standard therapies for asthma. Recent advances in biologic medications have enabled a more tailored approach to the care of patients with moderate to severe asthma, taking into consideration clinical traits and measurable biomarkers. This chapter will review heterogeneity in treatment response to different medication classes for asthma: inhaled and systemic corticosteroids, beta-2 agonists, leukotriene modifiers, muscarinic antagonists, macrolides, and biologics.

Lung Effects of Household Air Pollution

Biomass fuel smoke, secondhand smoke, and oxides of nitrogen are common causes of household air pollution (HAP). Almost 2.4 billion people worldwide use solid fuels for cooking and heating, mostly in low- and middle-income countries. Wood combustion for household heating is also common in many areas of high-income countries, and minorities are particularly vulnerable. HAP in low- and middle-income countries is associated with asthma, acute respiratory tract infections in adults and children, chronic obstructive pulmonary disease, lung cancer, tuberculosis, and respiratory mortality. Although wood smoke exposure levels in high-income countries are typically lower than in lower-income countries, it is similarly associated with accelerated lung function decline, higher prevalence of airflow obstruction and chronic bronchitis, and higher all-cause and respiratory cause-specific mortality. Household air cleaners with high-efficiency particle filters have mixed effects on asthma and chronic obstructive pulmonary disease outcomes. Biomass fuel interventions in low-income countries include adding chimneys to cookstoves, improving biomass fuel combustion stoves, and switching fuel to liquid petroleum gas. Still, the impact on health outcomes is inconsistent. In high-income countries, strategies for reducing biomass fuel-related HAP are centered on community-level woodstove changeout programs, although the results are again inconsistent. In addition, initiatives to encourage home smoking bans have mixed success in households with children. Environmental solutions to reduce HAP have varying success in reducing pollutants and health problems. Improved understanding of indoor air quality factors and actions that prevent degradation or improve polluted indoor air may lead to enhanced environmental health policies, but health outcomes must be rigorously examined.

Pharmacologic Management Strategies of Asthma-Chronic Obstructive Pulmonary Disease Overlap

The best therapeutic approach to patients with asthma-chronic obstructive pulmonary disease overlap (ACO) is unknown. Current treatment recommendations rely on expert opinions, roundtable discussions, and strategy documents, because patients with ACO have been excluded from most clinical studies in asthma and COPD. Because of the underlying asthma initial therapy, early use of inhaled corticosteroids along with a long-acting bronchodilator is recommended. If maintenance inhaler therapy is not effective, advanced therapies based on phenotyping and identification of treatable traits may be considered.

Asthma and Tobacco Smoking

Asthma is a prevalent chronic pulmonary condition with significant morbidity and mortality. Tobacco smoking is implicated in asthma pathophysiology, diagnosis, prognosis and treatment. Smokers display increased prevalence and incidence of asthma, but a causal association cannot be claimed using existing evidence. Second-hand smoking and passive exposure to tobacco in utero and early life have also been linked with asthma development. Currently, approximately one-fourth of asthma patients are smokers. Regular smokers with asthma might display accelerated lung function decline and non-reversible airflow limitation, making their distinction from chronic obstructive pulmonary disease patients challenging. Asthma patients who smoke typically have uncontrolled disease, as shown by increased symptoms, more exacerbations and impaired quality of life. On the other hand, smoking cessation improves lung function and asthma severity. Thus, asthma patients and their caregivers should be actively questioned about their smoking status at each medical encounter, and smoking cessation ought to be strongly encouraged both for patients with asthma and their close contacts. Smokers with asthma should be provided with comprehensive smoking cessation interventions on top of other anti-asthma medications.

Risk factors for asthma exacerbations during pregnancy: a systematic review and meta-analysis

BACKGROUND

Conflicting literature exists regarding the risk factors for exacerbations among pregnant women with asthma. This systematic review and meta-analysis aimed to determine risk factors for asthma exacerbations during pregnancy.

METHODS

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*) and (exacerb* or flare up or morbidit* or attack*).All studies published between 2000 and 24 August 2021 were considered for inclusion if they reported at least one potential risk factor of asthma exacerbations in pregnant women with asthma. Of the 3337 references considered, 35 publications involving 429 583 pregnant women with asthma were included. Meta-analyses were conducted to determine mean difference in risk factor between exacerbation groups, or the relative risks of exacerbation with certain risk factors. Good study quality was found through the Newcastle-Ottawa Scale (median score 8, interquartile range 7-9).

RESULTS

Increased maternal age (mean difference 0.62, 95% CI 0.11-1.13), obesity (relative risk 1.25, 95% CI 1.15-1.37), smoking (relative risk 1.35, 95% CI 1.04-1.75), black ethnicity (relative risk 1.62, 95% CI 1.52-1.73), multiparity (relative risk 1.31, 95% CI 1.01-1.68), depression/anxiety (relative risk 1.42, 95% CI 1.27-1.59), moderate-severe asthma (relative risk 3.44, 95% CI 2.03-5.83, versus mild) and severe asthma (relative risk 2.70, 95% CI 1.85-3.95, versus mild-moderate) were associated with an increased risk of asthma exacerbations during pregnancy.

CONCLUSIONS

Future interventions aimed at reducing exacerbations in pregnancy could address the modifiable factors, such as smoking and depression/anxiety, and introduce more regular monitoring for those with nonmodifiable risk factors such as obesity and more severe asthma.

Characteristics, phenotypes, mechanisms and management of severe asthma

ABSTRACT

Severe asthma is "asthma which requires treatment with high dose inhaled corticosteroids (ICS) plus a second controller (and/or systemic corticosteroids) to prevent it from becoming 'uncontrolled' or which remains 'uncontrolled' despite this therapy." The state of control was defined by symptoms, exacerbations and the degree of airflow obstruction. Therefore, for the diagnosis of severe asthma, it is important to have evidence for a diagnosis of asthma with an assessment of its severity, followed by a review of comorbidities, risk factors, triggers and an assessment of whether treatment is commensurate with severity, whether the prescribed treatments have been adhered to and whether inhaled therapy has been properly administered. Phenotyping of severe asthma has been introduced with the definition of a severe eosinophilic asthma phenotype characterized by recurrent exacerbations despite being on high dose ICS and sometimes oral corticosteroids, with a high blood eosinophil count and a raised level of nitric oxide in exhaled breath. This phenotype has been associated with a Type-2 (T2) inflammatory profile with expression of interleukin (IL)-4, IL-5, and IL-13. Molecular phenotyping has also revealed non-T2 inflammatory phenotypes such as Type-1 or Type-17 driven phenotypes. Antibody treatments targeted at the T2 targets such as anti-IL5, anti-IL5Rα, and anti-IL4Rα antibodies are now available for treating severe eosinophilic asthma, in addition to anti-immunoglobulin E antibody for severe allergic asthma. No targeted treatments are currently available for non-T2 inflammatory phenotypes. Long-term azithromycin and bronchial thermoplasty may be considered. The future lies with molecular phenotyping of the airway inflammatory process to refine asthma endotypes for precision medicine.

Cigarette Smoking and Asthma

Globally, around half the adult asthma population are current or former cigarette smokers. Cigarette smoking and asthma interact to induce an "asthma-smoking phenotype(s)," which has important implications for diagnosis, pathogenic mechanisms, and management. The lack of progress in understanding the effects of smoking on adults with asthma is due in part to their exclusion from most investigative studies and large clinical trials. In this review, we summarize the adverse clinical outcomes associated with cigarette smoking in asthma, highlight challenges in diagnosing asthma among cigarette smokers with chronic respiratory symptoms, particularly in older individuals with a long-standing smoking history, and review pathogenic mechanisms involving smoking- and asthma-related airway inflammation, tissue remodeling, corticosteroid insensitivity, and low-grade systemic inflammation. We discuss the key components of management including the importance of smoking cessation strategies, evidence for the effectiveness of the Global Initiative for Asthma recommendations on treatment in cigarette smokers, and the role of treatable traits such as type 2 eosinophilic airway inflammation. Lastly, we provide an algorithm to aid clinicians to manage current and former smokers with asthma. In the future, controlled and pragmatic trials in real-world populations should include cigarette smokers with asthma to provide an evidence base for treatment recommendations.

The influence of urban exposures and residence on childhood asthma

Children with asthma who live in urban neighborhoods experience a disproportionately high asthma burden, with increased incident asthma and increased asthma symptoms, exacerbations, and acute visits and hospitalizations for asthma. There are multiple urban exposures that contribute to pediatric asthma morbidity, including exposure to pest allergens, mold, endotoxin, and indoor and outdoor air pollution. Children living in urban neighborhoods also experience inequities in social determinants of health, such as increased poverty, substandard housing quality, increased rates of obesity, and increased chronic stress. These disparities then in turn can increase the risk of urban exposures and compound asthma morbidity as poor housing repair is a risk factor for pest infestation and mold exposure and poverty is a risk factor for exposure to air pollution. Environmental interventions to reduce in-home allergen concentrations have yielded inconsistent results. Population-level interventions including smoking bans in public places and legislation to decrease traffic-related air pollution have been successful at reducing asthma morbidity and improving lung function growth. Given the interface and synergy between urban exposures and social determinants of health, it is likely population and community-level changes will be needed to decrease the excess asthma burden in children living in urban neighborhoods.

Asthma-COPD Overlap Syndrome: Recent Insights and Unanswered Questions

The term asthma-COPD overlap (ACO) has been used to identify a heterogeneous condition in which patients present with airflow limitation that is not completely reversible and clinical and inflammatory features of both asthma and chronic obstructive pulmonary disease (COPD). ACO diagnosis may be difficult in clinical practice, while controversy still exists regarding its definition, pathophysiology, and impact. Patients with ACO experience a greater disease burden compared to patients with asthma or COPD alone, but in contrast they show better response to inhaled corticosteroid treatment than other COPD phenotypes. Current management recommendations focus on defining specific and measurable treatable clinical traits, according to disease phenotypes and underlying biological mechanisms for every single patient. In this publication, we review the current knowledge on definition, pathophysiology, clinical characteristics, and management options of ACO.

Reliever-Triggered Inhaled Glucocorticoid in Black and Latinx Adults with Asthma

BACKGROUND

Black and Latinx patients bear a disproportionate burden of asthma. Efforts to reduce the disproportionate morbidity have been mostly unsuccessful, and guideline recommendations have not been based on studies in these populations.

METHODS

In this pragmatic, open-label trial, we randomly assigned Black and Latinx adults with moderate-to-severe asthma to use a patient-activated, reliever-triggered inhaled glucocorticoid strategy (beclomethasone dipropionate, 80 μg) plus usual care (intervention) or to continue usual care. Participants had one instructional visit followed by 15 monthly questionnaires. The primary end point was the annualized rate of severe asthma exacerbations. Secondary end points included monthly asthma control as measured with the Asthma Control Test (ACT; range, 5 [poor] to 25 [complete control]), quality of life as measured with the Asthma Symptom Utility Index (ASUI; range, 0 to 1, with lower scores indicating greater impairment), and participant-reported missed days of work, school, or usual activities. Safety was also assessed.

RESULTS

Of 1201 adults (603 Black and 598 Latinx), 600 were assigned to the intervention group and 601 to the usual-care group. The annualized rate of severe asthma exacerbations was 0.69 (95% confidence interval [CI], 0.61 to 0.78) in the intervention group and 0.82 (95% CI, 0.73 to 0.92) in the usual-care group (hazard ratio, 0.85; 95% CI, 0.72 to 0.999; P = 0.048). ACT scores increased by 3.4 points (95% CI, 3.1 to 3.6) in the intervention group and by 2.5 points (95% CI, 2.3 to 2.8) in the usual-care group (difference, 0.9; 95% CI, 0.5 to 1.2); ASUI scores increased by 0.12 points (95% CI, 0.11 to 0.13) and 0.08 points (95% CI, 0.07 to 0.09), respectively (difference, 0.04; 95% CI, 0.02 to 0.05). The annualized rate of missed days was 13.4 in the intervention group and 16.8 in the usual-care group (rate ratio, 0.80; 95% CI, 0.67 to 0.95). Serious adverse events occurred in 12.2% of the participants, with an even distribution between the groups.

CONCLUSIONS

Among Black and Latinx adults with moderate-to-severe asthma, provision of an inhaled glucocorticoid and one-time instruction on its use, added to usual care, led to a lower rate of severe asthma exacerbations. (Funded by the Patient-Centered Outcomes Research Institute and others; PREPARE ClinicalTrials.gov number, NCT02995733.).

The Use of Inhaled Corticosteroids for Patients with COPD Who Continue to Smoke Cigarettes: An Evaluation of Current Practice

The use of inhaled corticosteroids (ICS) in combination with inhaled bronchodilators for patients with chronic obstructive pulmonary disease (COPD) is a common practice in primary care settings. However, ICS-containing therapies may be less effective in patients with COPD compared with asthma, and in individuals with COPD who continue to smoke cigarettes. Preclinical studies suggest that inflammation in COPD is very different from in asthma. Glucocorticoid receptor functioning and other innate anti-inflammatory mechanisms are altered in cells exposed to cigarette smoke. COPD may be relatively insensitive to ICS, especially in individuals who continue to smoke. ICS-containing therapies in patients with asthma who continue to smoke may also be less effective compared with patients who do not smoke. ICS-containing therapies may be inappropriately used in some patients with COPD, and their long-term use is associated with an increased risk for side effects, including pneumonia and bone fractures in some patients. Treatment for patients with COPD should be carefully evaluated, and anti-inflammatory/bronchodilatory strategies should be chosen based on individual patient characteristics and recommendations in current guidelines.

Effects of non-steroidal anti-inflammatory drugs and other eicosanoid pathway modifiers on antiviral and allergic responses: EAACI task force on eicosanoids consensus report in times of COVID-19

Non‐steroidal anti‐inflammatory drugs (NSAIDs) and other eicosanoid pathway modifiers are among the most ubiquitously used medications in the general population. Their broad anti‐inflammatory, antipyretic, and analgesic effects are applied against symptoms of respiratory infections, including SARS‐CoV‐2, as well as in other acute and chronic inflammatory diseases that often coexist with allergy and asthma. However, the current pandemic of COVID‐19 also revealed the gaps in our understanding of their mechanism of action, selectivity, and interactions not only during viral infections and inflammation, but also in asthma exacerbations, uncontrolled allergic inflammation, and NSAIDs‐exacerbated respiratory disease (NERD). In this context, the consensus report summarizes currently available knowledge, novel discoveries, and controversies regarding the use of NSAIDs in COVID‐19, and the role of NSAIDs in asthma and viral asthma exacerbations. We also describe here novel mechanisms of action of leukotriene receptor antagonists (LTRAs), outline how to predict responses to LTRA therapy and discuss a potential role of LTRA therapy in COVID‐19 treatment. Moreover, we discuss interactions of novel T2 biologicals and other eicosanoid pathway modifiers on the horizon, such as prostaglandin D2 antagonists and cannabinoids, with eicosanoid pathways, in context of viral infections and exacerbations of asthma and allergic diseases. Finally, we identify and summarize the major knowledge gaps and unmet needs in current eicosanoid research.

The Role of Comorbidities in Difficult-to-Control Asthma in Adults and Children

Assessment of asthma comorbidities, conditions that adversely affect the pathobiology of asthma or impair its response to therapies, is a fundamental step in the evaluation and management of patients with difficult-to-treat asthma. Identifying and effectively treating asthma comorbidities, such as obesity, obstructive sleep apnea, and chronic sinusitis with nasal polyps, may improve asthma control and reduce exacerbations. In addition, identifying comorbid T2 inflammatory conditions may help guide optimal selection of biologic therapies. Here, we describe common comorbid conditions found in adult and pediatric difficult-to-control asthma, discuss evidence for the association with asthma morbidity and treatment benefit, and provide information on how and when to assess comorbidities.

TH17 cells and corticosteroid insensitivity in severe asthma

Asthma is classically described as having either a type 2 (T2) eosinophilic phenotype or a non-T2 neutrophilic phenotype. T2 asthma usually responds to classical bronchodilation therapy and corticosteroid treatment. Non-T2 neutrophilic asthma is often more severe. Patients with non-T2 asthma or late-onset T2 asthma show poor response to the currently available anti-inflammatory therapies. These therapeutic failures result in increased morbidity and cost associated with asthma and pose a major health care problem. Recent evidence suggests that some non-T2 asthma is associated with elevated T_H17 cell immune responses. T_H17 cells producing Il-17A and IL-17F are involved in the neutrophilic inflammation and airway remodeling processes in severe asthma and have been suggested to contribute to the development of subsets of corticosteroid-insensitive asthma. This review explores the pathologic role of T_H17 cells in corticosteroid insensitivity of severe asthma and potential targets to treat this endotype of asthma.

Our evolving view of neutrophils in defining the pathology of chronic lung disease

Neutrophils are critical components of the body's immune response to infection, being loaded with a potent arsenal of toxic mediators and displaying immense destructive capacity. Given the potential of neutrophils to impart extensive tissue damage, it is perhaps not surprising that when augmented these cells are also implicated in the pathology of inflammatory diseases. Prominent neutrophilic inflammation is a hallmark feature of patients with chronic lung diseases such as chronic obstructive pulmonary disease, severe asthma, bronchiectasis and cystic fibrosis, with their numbers frequently associating with worse prognosis. Accordingly, it is anticipated that neutrophils are central to the pathology of these diseases and represent an attractive therapeutic target. However, in many instances, evidence directly linking neutrophils to the pathology of disease has remained somewhat circumstantial and strategies that have looked to reduce neutrophilic inflammation in the clinic have proved largely disappointing. We have classically viewed neutrophils as somewhat crude, terminally differentiated, insular and homogeneous protagonists of pathology. However, it is now clear that this does not do the neutrophil justice, and we now recognize that these cells exhibit heterogeneity, a pronounced awareness of the localized environment and a remarkable capacity to interact with and modulate the behaviour of a multitude of cells, even exhibiting anti-inflammatory, pro-resolving and pro-repair functions. In this review, we discuss evidence for the role of neutrophils in chronic lung disease and how our evolving view of these cells may impact upon our perceived assessment of their contribution to disease pathology and efforts to target them therapeutically.

Managing asthma in primary healthcare

Asthma brings considerable challenges for family doctors because of its variety of shapes, different levels of severity, a wide age range, and the fact that in the last decades clinicians are able to offer much better treatment options with a better level of disease control and a higher quality of life. The objectives of the current review article are to provide an up-to-date review by primary care respiratory leaders from different countries of the most significant challenges regarding asthma diagnosis and management, the importance of team work and the problems in recognizing and dealing with difficult-to-manage and severe asthma in primary care. The article provides a short review of the main challenges faced by family physicians and other primary health care professionals in supporting their patients in the management of asthma, such as asthma diagnosis, promoting access to spirometry, the importance of a multiprofessional team for the management of asthma, how to organize an asthma review, the promotion of patient autonomy and shared decision-making, improving the use of inhalers, the importance of the personalized asthma action plan, dealing with difficult-to-manage and severe asthma in primary care and choosing when, where and how to refer patients with severe asthma. The article also discusses the development of an integrated approach to asthma care in the community and the promotion of Asthma Right Care.

Treatment approaches for the patient with T2 low asthma

OBJECTIVE

To identify treatment approaches that can be used in the management of patients with asthma who lack significant type 2 inflammation, also called T2 low asthma.

DATA SOURCES

Recent expert guideline updates on the management of asthma, recent journal articles and review articles, and foundational journal articles are referenced.

STUDY SELECTIONS

This review cites clinical cohort studies of highly characterized patients with asthma, clinical interventional trials of high impact, mechanistic studies relevant to T2 low asthma, and emerging work in this area.

RESULTS

T2 low asthma accounts for approximately one-third to one-half of individuals with asthma. Characteristics of participants with T2 low asthma include higher body mass index, cigarette smoking/smoke exposure, relative lack of responsiveness to steroids, less bronchodilator reversibility, and often the presence of neutrophilic inflammation. Multiple available interventions target these characteristics, including standard inhalers, azithromycin, and lifestyle interventions of weight loss and smoking cessation.

CONCLUSION

Treatment of T2 low asthma should involve currently available approaches and will benefit from improved definition and understanding of disease pathobiology.

Recent Insights into the Management of Inflammation in Asthma

The present prevailing inflammatory paradigm in asthma is of T2-high inflammation orchestrated by key inflammatory cells like Type 2 helper lymphocytes, innate lymphoid cells group 2 and associated cytokines. Eosinophils are key components of this T2 inflammatory pathway and have become key therapeutic targets. Real-world evidence on the predominant T2-high nature of severe asthma is emerging. Various inflammatory biomarkers have been adopted in clinical practice to aid asthma characterization including airway measures such as bronchoscopic biopsy and lavage, induced sputum analysis, and fractional exhaled nitric oxide. Blood measures like eosinophil counts have also gained widespread usage and multicomponent algorithms combining different parameters are now appearing. There is also growing interest in potential future biomarkers including exhaled volatile organic compounds, micro RNAs and urinary biomarkers. Additionally, there is a growing realisation that asthma is a heterogeneous state with numerous phenotypes and associated treatable traits. These may show particular inflammatory patterns and merit-specific management approaches that could improve asthma patient outcomes. Inhaled corticosteroids (ICS) remain the mainstay of asthma management but their use earlier in the course of disease is being advocated. Recent evidence suggests potential roles for ICS in combination with long-acting beta-agonists (LABA) for as needed use in mild asthma whilst maintenance and reliever therapy regimes have gained widespread acceptance. Other anti-inflammatory strategies including ultra-fine particle ICS, leukotriene receptor antagonists and macrolide antibiotics may show efficacy in particular phenotypes too. Monoclonal antibody biologic therapies have recently entered clinical practice with significant impacts on asthma outcomes. Understanding of the efficacy and use of those agents is becoming clearer with a growing body of real-world evidence as is their potential applicability to other treatable comorbid traits. In conclusion, the evolving understanding of T2 driven inflammation alongside a treatable traits disease model is enhancing therapeutic approaches to address inflammation in asthma.

Asthma and Comorbid Conditions-Pulmonary Comorbidity

Pulmonary comorbidities can increase disease severity and health care costs associated with asthma management. Vocal cord dysfunction/inducible laryngeal obstruction is a common comorbidity that results from intermittent laryngeal obstruction. Patients describe distinct episodes of dyspnea that do not respond to bronchodilators. Inspiratory stridor is common. The gold standard diagnostic testing strategy is continuous laryngoscopy performed during exercise or irritant challenges. Dysfunctional breathing (DB) is an overarching term that describes conditions with a chronic change in the pattern of breathing that results in pulmonary and extrapulmonary symptoms. The prevalence of DB in asthma is up to 30%, and breathing retraining can improve symptoms and quality of life in people with DB and asthma. Asthma-chronic obstructive pulmonary disease overlap (ACO) refers to both asthmatics who develop fixed airflow obstruction after a history of exposure to smoke or biomass and patients with chronic obstructive pulmonary disease who have "asthmatic features" such as a large bronchodilator response, elevated levels of serum IgE, or peripheral eosinophil counts ≥300 per μL. Triple inhaler therapy with inhaled corticosteroid/long-acting beta-agonist/long-acting muscarinic should be considered in people with ACO and severe symptoms or frequent exacerbations. The clinical expression of bronchiectasis involves persistent mucus hypersecretion, recurrent exacerbations of infective bronchitis, incompletely reversible airflow obstruction, and lung fibrosis and can occur in up to 30% of adults with longstanding asthma. The treatable traits strategy is a useful model of care to manage the complexity and heterogeneity of asthma with pulmonary comorbidity.

Inhaled corticosteroid response in smoker versus non-smoker asthmatic patients: a cross-sectional study

Background

Asthmatic smokers are a distinct phenotype of asthma. There is a lack of specific information about the treatment of asthma in smokers. The purpose of this study was to compare the effects of inhaled corticosteroid (ICS) on asthmatic smokers and non-smokers.

Results

The present observational, cross-sectional study was conducted at the Chest Department in Assiut University Hospital, during the period from August 2018 to January 2020. Hundred and seventeen asthmatic patients (42 smokers, 30 ex-smokers, and 45 non-smokers) were assessed using an asthma control questionnaire (ACQ), spirometry, sputum cytology, and serum periostin and eotaxin-2 to compare between a patient on inhaled corticosteroid for at least 3 months and patients who do not receive any form of corticosteroid. Asthmatic smokers had poor response to ICS and had insignificant improvement as regard all parameters. However, asthmatic ex-smokers had a partial response to ICS. They had higher post-bronchodilator FEV1 in comparison to those who did not receive ICS. Asthmatic non-smokers on ICS showed the best response as they were well controlled as regard ACQ. Moreover, they had higher post-bronchodilator FEV1/FVC, post-bronchodilator FEV1, and post-bronchodilator FEF25-75, and lower sputum eosinophils and neutrophils.

Conclusion

Smoking adversely affects the course and response to ICS therapy in asthma.

Trial registration

Interrelation between bronchial asthma and smoking: ClinicalTrials.gov ID: NCT03207620. Registered 27 June 2017.

Oxidative Stress Promotes Corticosteroid Insensitivity in Asthma and COPD

Corticosteroid insensitivity is a key characteristic of patients with severe asthma and COPD. These individuals experience greater pulmonary oxidative stress and inflammation, which contribute to diminished lung function and frequent exacerbations despite the often and prolonged use of systemic, high dose corticosteroids. Reactive oxygen and nitrogen species (RONS) promote corticosteroid insensitivity by disrupting glucocorticoid receptor (GR) signaling, leading to the sustained activation of pro-inflammatory pathways in immune and airway structural cells. Studies in asthma and COPD models suggest that corticosteroids need a balanced redox environment to be effective and to reduce airway inflammation. In this review, we discuss how oxidative stress contributes to corticosteroid insensitivity and the importance of optimizing endogenous antioxidant responses to enhance corticosteroid sensitivity. Future studies should aim to identify how antioxidant-based therapies can complement corticosteroids to reduce the need for prolonged high dose regimens in patients with severe asthma and COPD.

Current long-acting muscarinic antagonists for the treatment of asthma

INTRODUCTION

The role of long-acting muscarinic antagonists (LAMAs) is well established in uncontrolled asthma, but not in milder stages.

AREAS COVERED

This review examines the main randomized controlled trials (RCTs) that have investigated LAMAs administered as monotherapy or in combination to asthmatic patients, according to the different phenotypes. It offers an overview of the role of LAMAs or their fixed dose combinations (FDCs) in the treatment across all the different stages of asthma.

EXPERT OPINION

Tiotropium is now widely recognized as treatment for moderate to severe uncontrolled asthma (step 4-5) in adults and children. The most recent new evidence is: a) in adults, three different LAMA/long-acting β₂-agonist (LABA)/inhaled corticosteroid (ICS) FDCs have been recently approved, extending the treatment options for these patients; b) therapy with LAMAs does not depend on patient's Th2 status and justifies the indication regardless of patient's phenotyping; c) in the milder stages, the high variability of response to LAMAs and the lack of a good phenotyping of patients represents the main obstacle in prescribing LAMAs. A better characterization of parasympathetic tone activity could improve LAMAs prescription.

Asthma/obstructive pulmonary disease overlap: update on definition, biomarkers, and therapeutics

PURPOSE OF REVIEW

Asthma/chronic obstructive pulmonary disease overlap (ACO) continues to be a poorly understood condition. This review discusses newly proposed criteria and potential biomarkers in ACO, to aid in diagnosis and research studies, and prudent therapeutic approaches.

RECENT FINDINGS

A global expert panel proposed an operational definition consisting of major and minor criteria as a step toward defining ACO. Serum periostin and YKL-40 may serve as biomarkers for ACO. Clinically, a reasonable therapeutic approach to ACO is the early addition of a long-acting β-agonist (LABA) and/or a long-acting muscarinic antagonist (LAMA) to an inhaled corticosteroid (ICS).

SUMMARY

Both the proposed criteria and the described biomarkers for ACO can help guide clinicians in identifying this condition as well as aid researchers in designing much needed future studies. In the meantime, clinicians can treat potential ACO patients using the above approach, until therapeutic studies in clearly defined ACO patients are performed.

Determinants of uncontrolled asthma among adult asthmatic patients on follow-up at chest clinic of Jimma medical center: unmatched case-control study

OBJECTIVE

To identify the determinants of uncontrolled asthma among asthmatic patients on follow-up at Jimma Medical Center.

METHODS

Institution-based case-control study was conducted on asthmatic patients who were on follow-up at the chest clinic of Jimma University Medical (JMC) from March to May 2020. A total of 59 cases and 118 controls (1: 2 ratio) were included in the study. Cases and controls were defined based on asthma control test (ACT) scores where those who had scores of ≤19 and above 19 were defined to be cases and controls, respectively.

RESULTS

Age of the patients [AOR: 2.78; 95% CI: 1.14, 6.81], age of the cases' residential houses [AOR: 3.65; 95% CI: 1.30, 10.28], presence of pets within the houses [AOR: 2.78; 95% CI: 1.29, 5.96], having rhinitis [AOR: 3.34; 95% CI: 1.17, 9.52], past asthma exacerbation [AOR: 2.38, 95% CI: 1.05, 5.40], non-adherence to treatment [AOR: 2.81; 95% CI: 1.30, 6.08] and smoking [AOR: 7.09; 95% CI: 1.84, 27.33] were found to be determinants of uncontrolled asthma.

CONCLUSIONS

Uncontrolled asthma results from multiple sociodemographic, environmental, clinical, and behavioral factors. Therefore, patients should be counseled on avoiding pets, maintenance of houses, adherence to treatment, quitting smoking, and early treatment-seeking for rhinitis and asthma exacerbation to improve asthma control comprehensively.

Phenotype-Guided Asthma Therapy: An Alternative Approach to Guidelines

Despite recent advances in therapy, a substantial proportion of asthmatics remain not well controlled. The classical stepwise approach to pharmacological therapy in adult asthma recommends that treatment is progressively stepped up by increasing the inhaled corticosteroid (ICS) dose or by adding another controller medication- to achieve symptom control and reduce the risk of exacerbations, and stepped down after a period of control. In general, asthma guideline recommendations do not reflect that there are significant differences between ICS in terms of potency. Moreover, they do not consider efficacy and safety separately, incorrectly assuming that "low" and "high" dose categories inevitably correspond with low and high risk of systemic effects. Another point of criticism is the fact that guidelines do not take into account the inflammatory profile of the patient, although substantial groups of patients with mild and moderate asthma have little evidence of "T2-high" inflammation, and by extension are likely to show a poor response to ICS treatment. On the other hand, the latest version of the Global Initiative for Asthma (GINA) equally recommends regular ICS and ICS/formoterol as needed to prevent exacerbations in step 2 patients, without taking into consideration that the therapeutic objectives (exacerbations, symptoms) may differ between individual patients and that different goals may warrant distinct treatment strategies. In this review, we bring to the table several controversial issues concerning asthma treatment and suggest an alternative proposal that takes into consideration the potential side effects of high ICS doses, the patient's inflammatory profile and the therapeutic goals to be achieved.

Neutrophils in asthma: the good, the bad and the bacteria

Airway inflammation plays a key role in asthma pathogenesis but is heterogeneous in nature. There has been significant scientific discovery with regard to type 2-driven, eosinophil-dominated asthma, with effective therapies ranging from inhaled corticosteroids to novel biologics. However, studies suggest that approximately 1 in 5 adults with asthma have an increased proportion of neutrophils in their airways. These patients tend to be older, have potentially pathogenic airway bacteria and do not respond well to classical therapies. Currently, there are no specific therapeutic options for these patients, such as neutrophil-targeting biologics.Neutrophils comprise 70% of the total circulatory white cells and play a critical defence role during inflammatory and infective challenges. This makes them a problematic target for therapeutics. Furthermore, neutrophil functions change with age, with reduced microbial killing, increased reactive oxygen species release and reduced production of extracellular traps with advancing age. Therefore, different therapeutic strategies may be required for different age groups of patients.The pathogenesis of neutrophil-dominated airway inflammation in adults with asthma may reflect a counterproductive response to the defective neutrophil microbial killing seen with age, resulting in bystander damage to host airway cells and subsequent mucus hypersecretion and airway remodelling. However, in children with asthma, neutrophils are less associated with adverse features of disease, and it is possible that in children, neutrophils are less pathogenic.In this review, we explore the mechanisms of neutrophil recruitment, changes in cellular function across the life course and the implications this may have for asthma management now and in the future. We also describe the prevalence of neutrophilic asthma globally, with a focus on First Nations people of Australia, New Zealand and North America.

Inhaled RNA Therapeutics for Obstructive Airway Diseases: Recent Advances and Future Prospects

Obstructive airway diseases, e.g., chronic obstructive pulmonary disease (COPD) and asthma, represent leading causes of morbidity and mortality worldwide. However, the efficacy of currently available inhaled therapeutics is not sufficient for arresting disease progression and decreasing mortality, hence providing an urgent need for development of novel therapeutics. Local delivery to the airways via inhalation is promising for novel drugs, because it allows for delivery directly to the target site of action and minimizes systemic drug exposure. In addition, novel drug modalities like RNA therapeutics provide entirely new opportunities for highly specific treatment of airway diseases. Here, we review state of the art of conventional inhaled drugs used for the treatment of COPD and asthma with focus on quality attributes of inhaled medicines, and we outline the therapeutic potential and safety of novel drugs. Subsequently, we present recent advances in manufacturing of thermostable solid dosage forms for pulmonary administration, important quality attributes of inhalable dry powder formulations, and obstacles for the translation of inhalable solid dosage forms to the clinic. Delivery challenges for inhaled RNA therapeutics and delivery technologies used to overcome them are also discussed. Finally, we present future prospects of novel inhaled RNA-based therapeutics for treatment of obstructive airways diseases, and highlight major knowledge gaps, which require further investigation to advance RNA-based medicine towards the bedside.

The Impact of Tobacco Smoking on Adult Asthma Outcomes

Background: Tobacco smoking is associated with more severe asthma symptoms, an accelerated decline in lung function, and reduced responses to corticosteroids. Our objective was to compare asthma outcomes in terms of disease control, exacerbation rates, and lung function in a population of asthmatic patients according to their smoking status. Methods: We compared patients’ demographics, disease characteristics, and lung-function parameters in current-smokers (CS, n = 48), former-smokers (FS, n = 38), and never-smokers (NS, n = 90), and identified predictive factors for asthma control. Results: CS had a higher prevalence of family asthma/atopy, a lower rate of controlled asthma, impaired perception of dyspnea, an increased number of exacerbations, and poorer lung function compared to NS. The mean asthma control questionnaire’s (ACQ) score was higher in CS vs. NS and FS (1.9 vs. 1.2, p = 0.02). Compared to CS, FS had a lower rate of exacerbations, a better ACQ score (similar to NS), a higher prevalence of dyspnea, and greater lung-diffusion capacity. Non-smoking status, the absence of dyspnea and exacerbations, and a forced expiratory volume in one second ≥80% of predicted were associated with controlled asthma. Conclusions: CS with asthma exhibit worse clinical and functional respiratory outcomes compared to NS and FS, supporting the importance of smoking cessation in this population.

Treatment options in type-2 low asthma

Monoclonal antibodies targeting IgE or the type-2 cytokines interleukin (IL)-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma, respectively. However, these therapies are not appropriate for 30-50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, "type-2 low" asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, yet poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity and occupational exposures and may be driven by persistent bacterial infections and by activation of a recently described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits that can be identified and addressed. We focus particularly on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally, we review ongoing research into other pathways including tumour necrosis factor, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems; it is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

[Smoking cessation in asthmatic patients and its impact]

INTRODUCTION

The prevalence of smoking in asthmatic patients is similar to, or even higher than in the general population.

OBJECTIVES

This systematic review addresses (1) the effects of smoking on asthma, (2) smoking cessation strategies in asthmatic patients, and (3) the consequences of smoking cessation for people with asthma.

RESULTS

Active or passive smoking can promote the development of asthma. The few studies on smoking cessation in asthma confirm the efficacy of validated smoking cessation strategies in these patients (nicotine replacement therapy, varenicline, bupropion, cognitive and behavioural therapies). Smoking cessation in parents with asthmatic children is essential and is based on the same strategies. Electronic cigarettes may be a useful help to quit smoking in some patients. Smoking cessation is beneficial in asthmatic smokers and associated with (1) a reduction of asthma symptoms, acute exacerbations, bronchial hyperresponsiveness, and bronchial inflammation, (2) decreased use of rescue medications and in doses of inhaled corticosteroids, (3) improved asthma control, quality of life, and lung function.

CONCLUSION

In asthmatic patients, it is essential to assess smoking status and health professionals must assist them to quit smoking.

Long-term adherence to inhaled corticosteroids and asthma control in adult-onset asthma

BACKGROUND

In short-term studies, poor adherence to inhaled corticosteroids (ICS) has been associated with worse asthma control, but the association of long-term adherence and disease control remains unclear.

OBJECTIVE

To assess the relationship between 12-year adherence to ICS and asthma control in patients with adult-onset asthma.

METHODS

As part of the Seinäjoki Adult Asthma Study, 181 patients with clinically confirmed new-onset adult asthma and regular ICS medication were followed-up for 12 years. Adherence (%) to ICS was assessed individually ((µg dispensed/µg prescribed)×100) during the follow-up. Asthma control was evaluated after 12 years of treatment according to the Global Initiative for Asthma 2010 guideline.

RESULTS

Asthma was controlled in 31% and not controlled (partly controlled or uncontrolled) in 69% of the patients. Patients with not-controlled asthma were more often male, older, nonatopic and used higher doses of ICS than those with controlled disease. The mean±sd 12-year adherence to ICS was 63±38% in patients with controlled asthma and 76±40% in patients with not-controlled disease (p=0.042). Among patients with not-controlled asthma, those with lower 12-year adherence (<80%) had more rapid decline in forced expiratory volume in 1 s (-47 mL·year-1) compared to patients with better adherence (≥80%) (-40 mL·year-1) (p=0.024). In contrast, this relationship was not seen in patients with controlled asthma.

CONCLUSIONS

In adult-onset asthma, patients with not-controlled disease showed better 12-year adherence to ICS treatment than those with controlled asthma. In not-controlled disease, adherence <80% was associated with more rapid lung function decline, underscoring the importance of early recognition of such patients in routine clinical practice.

Impact of Air Pollution on Asthma Outcomes

Asthma is a chronic respiratory disease characterized by variable airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Evidence suggests that air pollution has a negative impact on asthma outcomes in both adult and pediatric populations. The aim of this review is to summarize the current knowledge on the effect of various outdoor and indoor pollutants on asthma outcomes, their burden on its management, as well as to highlight the measures that could result in improved asthma outcomes. Traffic-related air pollution, nitrogen dioxide and second-hand smoking (SHS) exposures represent significant risk factors for asthma development in children. Nevertheless, a causal relation between air pollution and development of adult asthma is not clearly established. Exposure to outdoor pollutants can induce asthma symptoms, exacerbations and decreases in lung function. Active tobacco smoking is associated with poorer asthma control, while exposure to SHS increases the risk of asthma exacerbations, respiratory symptoms and healthcare utilization. Other indoor pollutants such as heating sources and molds can also negatively impact the course of asthma. Global measures, that aim to reduce exposure to air pollutants, are highly needed in order to improve the outcomes and management of adult and pediatric asthma in addition to the existing guidelines.