Mepolizumab depletes inflammatory but preserves homeostatic eosinophils in severe asthma.

BACKGROUND: Eosinophils are key therapeutic targets in severe asthma that are suppressed by IL5 (mepolizumab) and IL5 receptor (benralizumab) blockade. The effect of IL5 pathway biologics on recently described homeostatic (hEOs) and inflammatory (iEOs) eosinophil subsets is unknown. We aimed to determine the relative impact of mepolizumab and benralizumab treatment on eosinophil subset and phenotype, and explore clinical associations of eosinophil subsets with severe asthma characteristics and treatment response. METHODS: We performed a cross-sectional observational study of severe asthma (eosinophilic n = 32, non-eosinophilic n = 23, mepolizumab-treated n = 25), with longitudinal follow-up of 30 eosinophilic participants at two timepoints (4-24 weeks, >24 weeks) post-commencement of mepolizumab (n = 20) or benralizumab (n = 10). Blood hEOs and iEOs were measured by flow cytometry assessment of surface CD62L protein. RESULTS: iEO proportion was significantly lower in mepolizumab-treated participants in both the cross-sectional and longitudinal study. Mepolizumab and benralizumab depleted iEOs to a similar extent, however a significantly greater number of hEOs remained in mepolizumab participants at follow-up. Greater iEO proportion correlated with poorer asthma control in eosinophilic but not non-eosinophilic asthma. Higher residual iEO proportion correlated with poorer asthma control in mepolizumab-treated individuals. Reduced blood eosinophil viability was observed in around half of mepolizumab-treated participants, which was associated with significantly better asthma control and spirometry. CONCLUSIONS: Mepolizumab depletes iEOs and reduces circulating eosinophil viability in severe asthma but preserves a residual population of circulatory hEOs. In contrast benralizumab depleted both iEOs and hEOs. Higher iEO abundance and eosinophil viability are associated with poorer clinical outcomes following mepolizumab-treatment. Monitoring circulating eosinophil phenotype and viability may be useful to predict biologic treatment response in severe asthma.

Change is in the air: key questions on the 'Treatable Traits' model for chronic airway diseases in primary care.

Despite great advancements in the treatment of chronic airway diseases, improvements in morbidity and mortality have stalled in recent years. Asthma and chronic obstructive pulmonary disease are complex and heterogeneous diseases that require tailored management based on individual patient characteristics and needs. The Treatable Traits (TTs) approach aims to personalise and improve patient care through the identification and targeting of clinically relevant and modifiable pulmonary, extra-pulmonary and behavioural traits. In this article, we outline the rationale for TTs-based management and provide practical guidance for its application in primary care. To aid implementation, seven potential 'prime' traits are proposed: airflow obstruction, eosinophilic inflammation, adherence, inhaler technique, smoking, low body mass index/obesity and anxiety and depression-selected for their prevalence, recognisability and feasibility of use. Some of the key questions among healthcare professionals, that may be roadblocks to widespread application of a TTs model of care, are also addressed.

Physical capacity and inactivity in obstructive airway diseases: a "can do, do do" analysis.

Introduction: Physical capacity is an important determinant of physical activity in people with obstructive airway disease (OAD). This study aimed to extend the "can do, do do" concept in people with OAD, to identify if people categorised into quadrants based on physical capacity and activity differ by clinical and movement behaviour characteristics. Methods: A total of 281 participants (bronchiectasis n=60, severe asthma n=93, COPD n=70 and control n=58) completed assessments to characterise physical capacity as "can do" versus "can't do" (6-min walk distance < or ≥70% pred) and physical activity as "do do" versus "don't do" (accelerometer-derived moderate to vigorous intensity physical activity (MVPA) < or ≥150 min·week-1). Results: The control group had a greater proportion of people in the "can do, do do" quadrant compared with the OAD groups (76% versus 10-33%). People with OAD in the "can't do, don't do" quadrant had worse clinical characteristics (airflow limitation, comorbidities, quality of life and functional dyspnoea) and spent less time doing light-intensity physical activity (LPA) and more time being sedentary compared with the "can do, do do" quadrant. Discussion: This study highlights that many people with OAD may be inactive because they do not have the physical capacity to participate in MVPA, which is further impacted by greater disease severity. It is important to consider the potential benefits of addressing LPA and sedentary behaviour due to suboptimal levels of these movement behaviours across different quadrants. Future research is needed to investigate if tailoring intervention approaches based on quadrant allocation is effective in people with OAD.

Understanding Breathlessness Burden and Psychophysiological Correlates in Asthma.

BACKGROUND: Breathlessness is a disabling symptom, with complexity that is often under-recognized and undertreated in asthma. OBJECTIVE: To highlight the burden of breathlessness in people with severe compared with mild-to-moderate asthma and identify psychophysiological correlates of breathlessness. METHODS: This was a cross-sectional study of people with mild-to-severe asthma, who attended 2 in-person visits to complete a multidimensional assessment. The proportion of people with mild-to-moderate versus severe asthma who reported physically limiting breathlessness (modified Medical Research Council [mMRC] dyspnea score ≥2) was compared. Psychophysiological factors associated with breathlessness in people with asthma were identified via a directed acyclic graph and explored with multivariate logistic regression to predict breathlessness. RESULTS: A total of 144 participants were included, of whom, 74 (51%) had mild-to-moderate asthma and 70 (49%) severe asthma. Participants were predominantly female (n = 103, 72%) with a median (quartile 1, quartile 3) age of 63.4 (50.5, 69.5) years and body mass index (BMI) of 31.3 (26.2, 36.0) kg/m2. The proportion of people reporting mMRC ≥2 was significantly higher in those with severe- (n = 37, 53%) than those with mild-to-moderate (n = 21, 31%) asthma (P = .013). Dyspnoea-12 Total (8.00 [4.75, 17.00] vs 5.00 [2.00, 11.00], P = .037) score was also significantly higher in the severe asthma group. Significant predictors of physically limiting breathlessness were BMI, asthma control, exercise capacity, and hyperventilation symptoms. Airflow limitation and type 2 inflammation were poor breathlessness predictors. CONCLUSIONS: Over half of people with severe asthma experience physically limiting breathlessness despite treatment. Targeting psychophysiological factors, or traits, associated with breathlessness may help relieve this distressing symptom, which is of high priority to people with asthma.

Exploring Clinical Remission in Moderate Asthma - Perspectives from Asia, the Middle East, and South America.

INTRODUCTION: Clinical remission is a relatively new concept in asthma but recent research initiatives suggest it could be an ambitious and achievable therapeutic target for patients with asthma. METHODS: In this modified Delphi study (comprising two online surveys, completed either side of a virtual scientific workshop), the opinions of a panel of respiratory physicians were evaluated to summarize perspective statements on key therapeutic outcomes and criteria for on-treatment clinical remission in patients with moderate asthma. An agreement threshold was pre-defined as agreement by ≥ 75% of participants. RESULTS: Surveys 1 and 2 were completed by 20 and 18 participants, respectively. Most participants (95%) agreed with the concept of clinical remission in moderate asthma and that this should be a desirable treatment goal (90%). Based on a composite measure of 4-6 desirable therapeutic outcomes, current understanding of clinical remission was considered as 12 months with no exacerbations, no oral corticosteroids, no daytime or night-time asthma symptoms (Asthma Control Test score ≥ 20 or Asthma Control Questionnaire score ≤ 0.75), stable lung function, and no treatment-related adverse events. No agreement was reached on the role of relievers in defining therapeutic outcomes or on the wider use of biomarkers and airway hyperresponsiveness for defining asthma remission in clinical practice. CONCLUSIONS: In line with recent consensus statements from the United States and Europe, there was a high level of agreement on the elements of clinical remission among a panel of respiratory physicians from Asia, the Middle East, and South America. Extension of the concept of clinical remission to patients with moderate asthma was considered aligned with the potential of clinical remission as a goal of therapy.

Real-world biologics response and super-response in the International Severe Asthma Registry cohort.

BACKGROUND: Biologic asthma therapies reduce exacerbations and long-term oral corticosteroids (LTOCS) use in randomized controlled trials (RCTs); however, there are limited data on outcomes among patients ineligible for RCTs. Hence, we investigated responsiveness to biologics in a real-world population of adults with severe asthma. METHODS: Adults in the International Severe Asthma Registry (ISAR) with ≥24 weeks of follow-up were grouped into those who did, or did not, initiate biologics (anti-IgE, anti-IL5/IL5R, anti-IL4/13). Treatment responses were examined across four domains: forced expiratory volume in 1 second (FEV1) increase by ≥100 mL, improved asthma control, annualized exacerbation rate (AER) reduction ≥50%, and any LTOCS dose reduction. Super-response criteria were: FEV1 increase by ≥500 mL, new well-controlled asthma, no exacerbations, and LTOCS cessation or tapering to ≤5 mg/day. RESULTS: 5.3% of ISAR patients met basic RCT inclusion criteria; 2116/8451 started biologics. Biologic initiators had worse baseline impairment than non-initiators, despite having similar biomarker levels. Half or more of initiators had treatment responses: 59% AER reduction, 54% FEV1 increase, 49% improved control, 49% reduced LTOCS, of which 32%, 19%, 30%, and 39%, respectively, were super-responses. Responses/super-responses were more frequent in biologic initiators than in non-initiators; nevertheless, ~40-50% of initiators did not meet response criteria. CONCLUSIONS: Most patients with severe asthma are ineligible for RCTs of biologic therapies. Biologics are initiated in patients who have worse baseline impairments than non-initiators despite similar biomarker levels. Although biologic initiators exhibited clinical responses and super-responses in all outcome domains, 40-50% did not meet the response criteria.

Effect of fractional exhaled nitric oxide (FENO)-based asthma management during pregnancy versus usual care on infant development, temperament, sensory function and autism signs.

Asthma during pregnancy is associated with a range of adverse perinatal outcomes. It is also linked to increased rates of neurodevelopmental conditions in the offspring. We aimed to assess whether fractional exhaled nitric oxide (FENO)-based asthma management during pregnancy improves child developmental and behavioural outcomes compared to usual care. The Breathing for Life Trial was a randomised controlled trial that compared FENO-based asthma management during pregnancy to usual care. Participants were invited to the developmental follow-up, the Breathing for Life Trial - Infant Development study, which followed up infants at 6 weeks, 6 months and 12 months. The primary outcomes were measured in infants at 12 months using the Bayley-III: Cognitive, Language and Motor composite scores. Secondary outcomes included Bayley-III social-emotional and adaptive behaviour scores, autism likelihood and sensory and temperament outcomes. The exposure of interest was the randomised intervention group. Two hundred and twenty-two infants and their 217 participating mothers were recruited to the follow-up; 107 mothers were in the intervention group and 113 were in the control group. There was no evidence of an intervention effect for the primary outcomes: Bayley-III cognitive (mean = 108.9 control, 108.5 intervention, p = 0.93), language (mean = 95.9 control, 95.6 intervention, p = 0.87) and motor composite scores (mean = 97.2 control, 97.9 intervention, p = 0.25). Mean scores for secondary outcomes were also similar among infants born to control and FENO group mothers, with few results reaching p < 0.05. CONCLUSION:  In this sample, FENO-guided asthma treatment during pregnancy did not improve infant developmental outcomes in the first year of life. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: ACTRN12613000202763. WHAT IS KNOWN: • Maternal asthma during pregnancy has been associated with increased rates of neurodevelopmental conditions in offspring, including intellectual disability and autism. WHAT IS NEW: • This is the first study to examine how managing asthma during pregnancy via a FENO-guided algorithm or usual care affects infant developmental and behavioural outcomes. While the results of the study showed no impact of the intervention, and therefore do not support the integration of FENO-based management of asthma in antenatal settings for optimal infant development, they do send a positive message about the implications of active asthma management during pregnancy on infant developmental outcomes.

Exploring Definitions and Predictors of Response to Biologics for Severe Asthma.

BACKGROUND: Biologic effectiveness is often assessed as response, a term that eludes consistent definition. Identifying those most likely to respond in real-life has proven challenging. OBJECTIVE: To explore definitions of biologic responders in adults with severe asthma and investigate patient characteristics associated with biologic response. METHODS: This was a longitudinal cohort study using data from 21 countries, which shared data with the International Severe Asthma Registry. Changes in four asthma outcome domains were assessed in the 1-year period before and after biologic initiation in patients with a predefined level of prebiologic impairment. Responder cutoffs were 50% or greater reduction in exacerbation rate, 50% or greater reduction in long-term oral corticosteroid daily dose, improvement in one or more category in asthma control, and 100 mL or greater improvement in FEV1. Responders were defined using single and multiple domains. The association between prebiologic characteristics and postbiologic initiation response was examined by multivariable analysis. RESULTS: A total of 2,210 patients were included. Responder rate ranged from 80.7% (n = 566 of 701) for exacerbation response to 10.6% (n = 9 of 85) for a four-domain response. Many responders still exhibited significant impairment after biologic initiation: 46.7% (n = 206 of 441) of asthma control responders with uncontrolled asthma before the biologic still had incompletely controlled disease postbiologic initiation. Predictors of response were outcome-dependent. Lung function responders were more likely to have higher prebiologic FeNO (odds ratio = 1.20 for every 25-parts per billion increase), and shorter asthma duration (odds ratio = 0.81 for every 10-year increase in duration). Higher blood eosinophil count and the presence of type 2-related comorbidities were positively associated with higher odds of meeting long-term oral corticosteroid, control, and lung function responder criteria. CONCLUSIONS: Our findings underscore the multimodal nature of response, showing that many responders experience residual symptoms after biologic initiation and that predictors of response vary according to the outcome assessed.

Exploring Definitions and Predictors of Severe Asthma Clinical Remission Post-Biologic in Adults.

RATIONALE: There is no consensus on criteria to include in an asthma remission definition in real-life. Factors associated with achieving remission post-biologic-initiation remain poorly understood. OBJECTIVES: To quantify the proportion of adults with severe asthma achieving multi-domain-defined remission post-biologic-initiation and identify pre-biologic characteristics associated with achieving remission which may be used to predict it. METHODS: This was a longitudinal cohort study using data from 23 countries from the International Severe Asthma Registry. Four asthma outcome domains were assessed in the 1-year pre- and post-biologic-initiation. A priori-defined remission cut-offs were: 0 exacerbations/year, no long-term oral corticosteroid (LTOCS), partly/well-controlled asthma, and percent predicted forced expiratory volume in one second ≥80%. Remission was defined using 2 (exacerbations + LTOCS), 3 (+control or +lung function) and 4 of these domains. The association between pre-biologic characteristics and post-biologic remission was assessed by multivariable analysis. MEASUREMENTS AND MAIN RESULTS: 50.2%, 33.5%, 25.8% and 20.3% of patients met criteria for 2, 3 (+control), 3 (+lung function) and 4-domain-remission, respectively. The odds of achieving 4-domain remission decreased by 15% for every additional 10-years asthma duration (odds ratio: 0.85; 95% CI: 0.73, 1.00). The odds of remission increased in those with fewer exacerbations/year, lower LTOCS daily dose, better control and better lung function pre-biologic-initiation. CONCLUSIONS: One in 5 patients achieved 4-domain remission within 1-year of biologic-initiation. Patients with less severe impairment and shorter asthma duration at initiation had a greater chance of achieving remission post-biologic, indicating that biologic treatment should not be delayed if remission is the goal. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The illness burden of severe asthma contrasted to people with mild-to-moderate asthma: a qualitative study.

Background: Disabling symptoms of asthma including breathlessness, cough, wheeze and chest tightness largely impact quality of life; however, how these symptoms impact people with asthma of different severity levels remains unknown. This study aimed to compare and characterise patients' symptom experience and the burden caused, their quality of life, and the medication preferences of people with severe asthma against those of people with mild-to-moderate asthma. Methods: This was a multisite qualitative study involving two focus groups and semistructured interviews of adults with severe asthma undertaken in Australia and UK. Interviews were also undertaken in people with mild-to-moderate asthma. Audio recordings were transcribed and analysed thematically. Results: Participants in both severe asthma and mild-to-moderate asthma groups had a mean±sd age of 57±12 years. Between the severe asthma and mild-to-moderate asthma groups, 62% of participants were female and 86% lived with family. Themes were identified: 1) what is asthma and most bothersome symptoms: both groups reported breathlessness as the most bothersome symptom; 2) impacts on life: disease-related impact differed as people with severe asthma reported significant burden in their quality of life, which encompassed emotional, physical, social and financial wellbeing; and 3) personalised and responsive care: severe asthma interviewees preferred injectable biological therapy as a mode of treatment administration. Conclusions: People with asthma are burdened by breathlessness and cough and other disabling symptoms resulting in impaired quality of life. Understanding the experiences of people with asthma of different severities can improve the patient-clinician partnership.

Oral corticosteroid stewardship: key insights from the Australasian Severe Asthma Registry.

BACKGROUND: People with severe asthma remain at risk of toxicity from maintenance oral corticosteroid (OCS) use and/or frequent OCS burst therapy. Cumulative exposures above 500-1000 mg prednisolone are associated with adverse effects, and recently OCS stewardship principles were promulgated to guide OCS prescription. AIMS: To examine real-world registry data to quantify OCS burden, ascertain trends over time in prescription and assess whether opportunities to implement steroid-sparing strategies were utilised. METHODS: Participants were enrolled in the Australasian Severe Asthma Registry for the period 2013-2021. Assessments were taken at enrolment and then annual follow-up, which included asthma control and OCS use. Descriptive analyses were performed, and subgroups were compared at baseline and over time. RESULTS: Nine hundred and twenty-four participants were evaluated and 215/924 (23%) were taking maintenance OCS at baseline, with 44% and 32% of participants having exposure to ≥500 or 1000 mg of OCS respectively in the prior year. Twelve months later, an additional 10% and 9% of participants reached cumulative doses of 500 or 1000 mg. People exceeding thresholds had ongoing poor asthma control. At baseline, 240/924 (26%) people were treated with asthma biological therapy. An additional 83 (12%) participants were identified as potentially benefiting from this steroid-sparing medication. Of these patients, only 23% commenced a biologic agent in the next 12 months. CONCLUSIONS: A large national asthma registry identifies exposure to toxic cumulative doses of OCS in more than a third of participants, with further subsequent cumulative dose escalation over 2 years. Steroid-sparing strategies were often not employed, highlighting the need for implementation of OCS stewardship initiatives.

Landscape fire smoke airway exposure impairs respiratory and cardiac function and worsens experimental asthma.

BACKGROUND: Millions of people are exposed to landscape fire smoke (LFS) globally, and inhalation of LFS particulate matter (PM) is associated with poor respiratory and cardiovascular outcomes. However, how LFS affects respiratory and cardiovascular function is less well understood. OBJECTIVE: We aimed to characterize the pathophysiologic effects of representative LFS airway exposure on respiratory and cardiac function and on asthma outcomes. METHODS: LFS was generated using a customized combustion chamber. In 8-week-old female BALB/c mice, low (25 µg/m3, 24-hour equivalent) or moderate (100 µg/m3, 24-hour equivalent) concentrations of LFS PM (10 µm and below [PM10]) were administered daily for 3 (short-term) and 14 (long-term) days in the presence and absence of experimental asthma. Lung inflammation, gene expression, structural changes, and lung function were assessed. In 8-week-old male C57BL/6 mice, low concentrations of LFS PM10 were administered for 3 days. Cardiac function and gene expression were assessed. RESULTS: Short- and long-term LFS PM10 airway exposure increased airway hyperresponsiveness and induced steroid insensitivity in experimental asthma, independent of significant changes in airway inflammation. Long-term LFS PM10 airway exposure also decreased gas diffusion. Short-term LFS PM10 airway exposure decreased cardiac function and expression of gene changes relating to oxidative stress and cardiovascular pathologies. CONCLUSIONS: We characterized significant detrimental effects of physiologically relevant concentrations and durations of LFS PM10 airway exposure on lung and heart function. Our study provides a platform for assessment of mechanisms that underpin LFS PM10 airway exposure on respiratory and cardiovascular disease outcomes.

Effect of Azithromycin on Asthma Remission in Adults With Persistent Uncontrolled Asthma: A Secondary Analysis of a Randomized, Double-Anonymized, Placebo-Controlled Trial.

BACKGROUND: Asthma remission is a potential treatment goal. RESEARCH QUESTION: Does adding azithromycin to standard therapy in patients with persistent uncontrolled asthma induce remission compared with placebo? STUDY DESIGN AND METHODS: This secondary analysis used data from the Asthma and Macrolides: the Azithromycin Efficacy and Safety (AMAZES) clinical trial-a double-anonymized placebo-controlled trial that evaluated the safety and efficacy of azithromycin on asthma exacerbations. The primary remission definition (referred to as clinical remission) was zero exacerbations and zero oral corticosteroids during the previous 6 months evaluated at 12 months and a 5-item Asthma Control Questionnaire score ≤ 1 at 12 months. Secondary remission definitions included clinical remission plus lung function criteria (postbronchodilator FEV1 ≥ 80% or postbronchodilator FEV1 ≤ 5% decline from baseline) and complete remission (sputum eosinophil count < 3% plus the aforementioned criteria). Sensitivity analyses explored the robustness of primary and secondary remission definitions. The predictors of clinical remission were identified. RESULTS: A total of 335 participants (41.5% male; median age, 61.01 years; quartile 1-3, 51.03-68.73) who completed the 12-month treatment period were included in the analysis. Twelve months of treatment with azithromycin induced asthma remission in a subgroup of patients, and a significantly higher proportion in the azithromycin arm achieved both clinical remission (50.6% vs 38.9%; P = .032) and clinical remission plus lung function criteria (50.8% vs 37.1%; P = .029) compared with placebo, respectively. In addition, a higher proportion of the azithromycin group achieved complete remission (23% vs 13.7%; P = .058). Sensitivity analyses supported these findings. Baseline factors (eg, better asthma-related quality of life, absence of oral corticosteroid burst in the previous year) predicted the odds of achieving clinical remission. Azithromycin induced remission in both eosinophilic and noneosinophilic asthma. INTERPRETATION: In this study, adults with persistent symptomatic asthma achieved a higher remission rate when treated with azithromycin. Remission on treatment may be an achievable treatment target in moderate/severe asthma, and future studies should consider remission as an outcome measure.

In utero smoking exposure induces changes to lung clearance index and modifies risk of wheeze in infants.

BACKGROUND: Fetal exposure to tobacco smoking throughout pregnancy is associated with wheezing in infancy. We investigated the influence of in utero smoking exposure on lung ventilation homogeneity and the relationship between lung ventilation inhomogeneity at 7 weeks of age and wheezing in the first year of life. METHODS: Maternal smoking was defined as self-reported smoking of tobacco or validated by exhaled (e)CO > 6 ppm. Lung function data from healthy infants (age 5-9 weeks) born to asthmatic mothers and parent-reported respiratory questionnaire data aged 12 months were collected in the Breathing for Life Trial (BLT) birth cohort. Tidal breathing analysis and SF6-based Multiple Breath Washout testing were performed in quiet sleep. Descriptive statistics and regression analysis were used to assess associations. RESULTS: Data were collected on 423 participants. Infants born to women who self-reported smoking during pregnancy (n = 42) had higher lung clearance index (LCI) than those born to nonsmoking mothers (7.90 vs. 7.64; p = .030). Adjusted regression analyzes revealed interactions between self-reported smoking and LCI (RR: 1.98, 95% CI: 1.07-3.63, 0.028, for each unit increase in LCI) and between eCO > 6 ppm and LCI (RR: 2.25, 95% CI: 1.13-4.50, 0.022) for the risk of wheeze in the first year of life. CONCLUSION: In utero tobacco smoke exposure induces lung ventilation inhomogeneities. Furthermore, an interaction between smoke exposure and lung ventilation inhomogeneities increases the risk of having a wheeze in the first year of life.

Activated non-neuronal cholinergic system correlates with non-type 2 inflammation and exacerbations in severe asthma.

BACKGROUND: Non-neuronal cholinergic system (NNCS) contributes to various inflammatory airway diseases. However, the role of NNCS in severe asthma (SA) remains largely unexplored. OBJECTIVE: To explore airway NNCS in SA. METHODS: In this prospective cohort study based on the Australasian Severe Asthma Network in a real-world setting, patients with SA (n = 52) and non-SA (n = 104) underwent clinical assessment and sputum induction. The messenger RNA (mRNA) levels of NNCS components and proinflammatory cytokines in the sputum were detected using real-time quantitative polymerase chain reaction, and the concentrations of acetylcholine (Ach)-related metabolites were evaluated using liquid chromatography coupled with tandem mass spectrometry. Asthma exacerbations were prospectively investigated during the next 12 months. The association between NNCS and future asthma exacerbations was also analyzed. RESULTS: Patients with SA were less controlled and had worse airway obstruction, a lower bronchodilator response, higher doses of inhaled corticosteroids, and more add-on treatments. The sputum mRNA levels of NNCS components, such as muscarinic receptors M1R-M5R, OCT3, VACHT, and ACHE; proinflammatory cytokines; and Ach concentration in the SA group were significantly higher than those in the non-SA group. Furthermore, most NNCS components positively correlated with non-type (T) 2 inflammatory profiles, such as sputum neutrophils, IL8, and IL1B. In addition, the mRNA levels of sputum M2R, M3R, M4R, M5R, and VACHT were independently associated with an increased risk of moderate-to-severe asthma exacerbations. CONCLUSION: This study indicated that the NNCS was significantly activated in SA, leading to elevated Ach and was associated with clinical features, non-T2 inflammation, and future exacerbations of asthma, highlighting the potential role of the NNCS in the pathogenesis of SA. CLINICAL TRIAL REGISTRATION: ChiCTR-OOC-16009529 (http://www.chictr.org.cn).

International Variation in Severe Exacerbation Rates in Patients With Severe Asthma.

BACKGROUND: Exacerbation frequency strongly influences treatment choices in patients with severe asthma. RESEARCH QUESTION: What is the extent of the variability of exacerbation rate across countries and its implications in disease management? STUDY DESIGN AND METHODS: We retrieved data from the International Severe Asthma Registry, an international observational cohort of patients with a clinical diagnosis of severe asthma. We identified patients aged ≥ 18 years who did not initiate any biologics prior to baseline visit. A severe exacerbation was defined as the use of oral corticosteroids for ≥ 3 days or asthma-related hospitalization/ED visit. A series of negative binomial models were applied to estimate country-specific severe exacerbation rates during 365 days of follow-up, starting from a naive model with country as the only variable to an adjusted model with country as a random-effect term and patient and disease characteristics as independent variables. RESULTS: The final sample included 7,510 patients from 17 countries (56% from the United States), contributing to 1,939 severe exacerbations (0.27/person-year). There was large between-country variation in observed severe exacerbation rate (minimum, 0.04 [Argentina]; maximum, 0.88 [Saudi Arabia]; interquartile range, 0.13-0.54), which remained substantial after adjusting for patient characteristics and sampling variability (interquartile range, 0.16-0.39). INTERPRETATION: Individuals with similar patient characteristics but coming from different jurisdictions have varied severe exacerbation risks, even after controlling for patient and disease characteristics. This suggests unknown patient factors or system-level variations at play. Disease management guidelines should recognize such between-country variability. Risk prediction models that are calibrated for each jurisdiction will be needed to optimize treatment strategies.

Adverse neonatal outcomes in pregnant women with asthma: An updated systematic review and meta-analysis.

BACKGROUND: A systematic review and meta-analysis from 2013 reported increased risks of congenital malformations, neonatal death and neonatal hospitalization amongst infants born to women with asthma compared to infants born to mothers without asthma. OBJECTIVE: Our objective was to update the evidence on the associations between maternal asthma and adverse neonatal outcomes. SEARCH STRATEGY: We performed an English-language MEDLINE, Embase, CINAHL, and COCHRANE search with the terms (asthma or wheeze) and (pregnan* or perinat* or obstet*). SELECTION CRITERIA: Studies published from March 2012 until September 2023 reporting at least one outcome of interest (congenital malformations, stillbirth, neonatal death, perinatal mortality, neonatal hospitalization, transient tachypnea of the newborn, respiratory distress syndrome and neonatal sepsis) in a population of women with and without asthma. DATA COLLECTION AND ANALYSIS: The study was reported following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Quality of individual studies was assessed by two reviewers independently using the Newcastle-Ottawa Scale. Random effects models (≥3 studies) or fixed effect models (≤2 studies) were used with restricted maximum likelihood to calculate relative risk (RR) from prevalence data and the inverse generic variance method where adjusted odds ratios (aORs) from individual studies were combined. MAIN RESULTS: A total of 18 new studies were included, along with the 22 studies from the 2013 review. Previously observed increased risks remained for perinatal mortality (relative risk [RR] 1.14, 95% confidence interval [CI]: 1.05, 1.23 n = 16 studies; aOR 1.07, 95% CI: 0.98-1.17 n = 6), congenital malformations (RR 1.36, 95% CI: 1.32-1.40 n = 17; aOR 1.42, 95% CI: 1.38-1.47 n = 6), and neonatal hospitalization (RR 1.27, 95% CI: 1.25-1.30 n = 12; aOR 1.1, 95% CI: 1.07-1.16 n = 3) amongst infants born to mothers with asthma, while the risk for neonatal death was no longer significant (RR 1.33, 95% CI: 0.95-1.84 n = 8). Previously reported non-significant risks for major congenital malformations (RR1.18, 95% CI: 1.15-1.21; aOR 1.20, 95% CI: 1.15-1.26 n = 3) and respiratory distress syndrome (RR 1.25, 95% CI: 1.17-1.34 n = 4; aOR 1.09, 95% CI: 1.01-1.18 n = 2) reached statistical significance. CONCLUSIONS: Healthcare professionals should remain aware of the increased risks to neonates being born to mothers with asthma.

Personal strategies to reduce the effects of landscape fire smoke on asthma-related outcomes: a protocol for systematic review and meta-analysis.

INTRODUCTION: Landscape fire smoke (LFS) contains several hazardous air pollutants that are known to be detrimental to human health. People with asthma are more vulnerable to the health impact of LFS than general populations. The aim of this review is to investigate the effectiveness of personal strategies to reduce the effect of LFS on asthma-related outcomes. METHODS AND ANALYSIS: We will electronically search databases such as Medline, Embase, CINAHL and Cochrane Clinical Trials Register to identify eligible articles for the review. Screening of search results and data extraction from included studies will be completed by two independent reviewers. The risk of bias (RoB 2) will be assessed using the Risk of Bias Assessment Tool for Non-Randomised Studies for observational studies, the Cochrane Collaboration tool for assessing the RoB 2 for randomised controlled trials (RCTs) and the Risk Of Bias In Nonrandomized Studies of Interventions tool for non-RCTs. A random-effect meta-analysis will be performed to determine the pooled summary of findings of the included studies. If meta-analysis is not possible, we will conduct a narrative synthesis. Findings will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. ETHICS AND DISSEMINATION: This study will synthesise the available evidence obtained from published studies and as such, no ethical approval is required. The review will be disseminated through peer-reviewed publications and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42022341120.