Exploring definitions and predictors of response to biologics for severe asthma.

BACKGROUND: Biologic effectiveness is often assessed as 'response', a term which 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 4 asthma outcome domains were assessed in the 1-year period pre- and post-biologic-initiation in patients with predefined level of pre-biologic impairment. Responder cut-offs were: ≥50% reduction in exacerbation rate, ≥50% reduction in long-term oral corticosteroid [LTOCS] daily dose, ≥1 category improvement in asthma control, and ≥100mL improvement in FEV1. Responders were defined using single- and multiple-domains. The association between pre-biologic characteristics and post-biologic-initiation response were examined by multivariable analysis. RESULTS: 2,210 patients were included. Responder rate ranged from 80.7% (n=566/701) for exacerbation-response to 10.6% (n=9/85) for 4-domain-response. Many responders still exhibited significant impairment post-biologic-initiation: 46.7% (n=206/441) of asthma control-responders with uncontrolled asthma pre-biologic still had incompletely-controlled disease post-biologic-initiation. Predictors of response were outcome-dependent. Lung function-responders were more likely to have higher pre-biologic FeNO (OR:1.20 for every 25ppb increase), and shorter asthma duration (OR:0.81, for every 10-year increase in duration). Higher BEC and presence of T2-related comorbidities were positively associated with higher odds of meeting LTOCS-, control- and lung function-responder criteria. CONCLUSION: Our findings underscore the multi-modal nature of 'response', show that many responders experience residual symptoms post-biologic-initiation, and that predictors of response vary according to outcome assessed.

Biomarkers and clinical outcomes after tezepelumab cessation: extended follow-up from the 2-year DESTINATION study.

BACKGROUND: Long-term tezepelumab treatment in the DESTINATION study (NCT03706079) resulted in reduced asthma exacerbations, reduced biomarker levels and improved lung function and symptom control in patients with severe, uncontrolled asthma. OBJECTIVE: To explore time course of changes in biomarkers and clinical manifestations following treatment cessation after 2 years of tezepelumab treatment. METHODS: DESTINATION was a two-year, phase 3, multicenter, randomized, placebo-controlled, double-blind study of tezepelumab treatment in patients (12-80 years old) with severe asthma. Patients received their last treatment doses at week 100 and could enroll in an extended follow-up (EFU) period from week 104 to 140. Change over time in key biomarkers and clinical outcomes were assessed in tezepelumab versus placebo recipients for 40 weeks after stopping treatment. RESULTS: Of 569 patients enrolled in the EFU period, 426 were included in the analysis (289 received tezepelumab and 137 placebo). Over the 40-week period after the last tezepelumab dose, blood eosinophil counts (BEC), fractional exhaled nitric oxide (FeNO) levels and Asthma Control Questionnaire-6 scores gradually increased from weeks 4-10, with a gradual reduction in pre-bronchodilator forced expiratory volume in 1 second such that BECs, FeNO levels and clinical outcomes returned to placebo levels; however, none of these outcomes returned to baseline levels. Total immunoglobulin E levels increased later from week 28 and remained well below placebo and baseline levels during the 40-week period after the last tezepelumab dose. CONCLUSION: This analysis demonstrates benefits of continued tezepelumab treatment in the management of patients with severe, uncontrolled asthma, compared with stopping treatment after 2 years.

Association between pre-biologic T2-biomarker combinations and response to biologics in patients with severe asthma.

Background: To date, studies investigating the association between pre-biologic biomarker levels and post-biologic outcomes have been limited to single biomarkers and assessment of biologic efficacy from structured clinical trials. Aim: To elucidate the associations of pre-biologic individual biomarker levels or their combinations with pre-to-post biologic changes in asthma outcomes in real-life. Methods: This was a registry-based, cohort study using data from 23 countries, which shared data with the International Severe Asthma Registry (May 2017-February 2023). The investigated biomarkers (highest pre-biologic levels) were immunoglobulin E (IgE), blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO). Pre- to approximately 12-month post-biologic change for each of three asthma outcome domains (i.e. exacerbation rate, symptom control and lung function), and the association of this change with pre-biologic biomarkers was investigated for individual and combined biomarkers. Results: Overall, 3751 patients initiated biologics and were included in the analysis. No association was found between pre-biologic BEC and pre-to-post biologic change in exacerbation rate for any biologic class. However, higher pre-biologic BEC and FeNO were both associated with greater post-biologic improvement in FEV1 for both anti-IgE and anti-IL5/5R, with a trend for anti-IL4Rα. Mean FEV1 improved by 27-178 mL post-anti-IgE as pre-biologic BEC increased (250 to 1000 cells/µL), and by 43-216 mL and 129-250 mL post-anti-IL5/5R and -anti-IL4Rα, respectively along the same BEC gradient. Corresponding improvements along a FeNO gradient (25-100 ppb) were 41-274 mL, 69-207 mL and 148-224 mL for anti-IgE, anti-IL5/5R, and anti-IL4Rα, respectively. Higher baseline BEC was also associated with lower probability of uncontrolled asthma (OR 0.392; p=0.001) post-biologic for anti-IL5/5R. Pre-biologic IgE was a poor predictor of subsequent pre-to-post-biologic change for all outcomes assessed for all biologics. The combination of BEC + FeNO marginally improved the prediction of post-biologic FEV1 increase (adjusted R2: 0.751), compared to BEC (adjusted R2: 0.747) or FeNO alone (adjusted R2: 0.743) (p=0.005 and <0.001, respectively); however, this prediction was not improved by the addition of IgE. Conclusions: The ability of higher baseline BEC, FeNO and their combination to predict biologic-associated lung function improvement may encourage earlier intervention in patients with impaired lung function or at risk of accelerated lung function decline.

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/).

Biological treatment of obstructive lung diseases.

In the last 30 years, the treatment of obstructive lung diseases, such as asthma and COPD, has seen significant advancements. Introduction of inhaled corticosteroids (ICS) and, more recently, biological treatments has revolutionized care. Biological treatments are very successful in severe asthma and are expected to be approved for COPD soon. Systematic assessment and multidimensional treatment approaches are crucial in both conditions. Future care may involve specialized centres for severe obstructive lung diseases, focusing on personalized approaches and monitoring, as argued in this review.

The airway epithelium: an orchestrator of inflammation, a key structural barrier and a therapeutic target in severe asthma.

Asthma is a disease of heterogeneous pathology, typically characterised by excessive inflammatory and bronchoconstrictor responses to the environment. The clinical expression of the disease is a consequence of the interaction between environmental factors and host factors over time, including genetic susceptibility, immune dysregulation and airway remodelling. As a critical interface between the host and the environment, the airway epithelium plays an important role in maintaining homeostasis in the face of environmental challenges. Disruption of epithelial integrity is a key factor contributing to multiple processes underlying asthma pathology. In this review, we first discuss the unmet need in asthma management and provide an overview of the structure and function of the airway epithelium. We then focus on key pathophysiological changes that occur in the airway epithelium, including epithelial barrier disruption, immune hyperreactivity, remodelling, mucus hypersecretion and mucus plugging, highlighting how these processes manifest clinically and how they might be targeted by current and novel therapeutics.

Airway hyperresponsiveness in asthma: The role of the epithelium.

Airway hyperresponsiveness (AHR) is a key clinical feature of asthma. The presence of AHR in people with asthma provides the substrate for bronchoconstriction in response to numerous diverse stimuli, contributing to airflow limitation and symptoms including breathlessness, wheeze, and chest tightness. Dysfunctional airway smooth muscle significantly contributes to AHR and is displayed as increased sensitivity to direct pharmacologic bronchoconstrictor stimuli, such as inhaled histamine and methacholine (direct AHR), or to endogenous mediators released by activated airway cells such as mast cells (indirect AHR). Research in in vivo human models has shown that the disrupted airway epithelium plays an important role in driving inflammation that mediates indirect AHR in asthma through the release of cytokines such as thymic stromal lymphopoietin and IL-33. These cytokines upregulate type 2 cytokines promoting airway eosinophilia and induce the release of bronchoconstrictor mediators from mast cells such as histamine, prostaglandin D2, and cysteinyl leukotrienes. While bronchoconstriction is largely due to airway smooth muscle contraction, airway structural changes known as remodeling, likely mediated in part by epithelial-derived mediators, also lead to airflow obstruction and may enhance AHR. In this review, we outline the current knowledge of the role of the airway epithelium in AHR in asthma and its implications on the wider disease. Increased understanding of airway epithelial biology may contribute to better treatment options, particularly in precision medicine.

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 exacerbations 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 ≥ 18 years of age 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 naïve 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.

Long-term health care resource and cost savings with allergy immunotherapy: REACT study results.

Background: Allergy immunotherapy (AIT) can be administered as subcutaneous immunotherapy (SCIT) injections in the clinic or as sublingual immunotherapy (SLIT) tablets at home after initiation under medical supervision. To achieve long-term, sustained effects, a 3-year treatment duration is recommended. Objective: Our aim was to assess the association of AIT (SCIT and SLIT tablets) with long-term health care resource use (HRU) and costs in subjects with allergic rhinitis. Methods: REACT was a retrospective propensity score-matched cohort study using claims data from a German health insurance database (2007-2017), with up to 9 years of follow-up after AIT initiation. HRU and costs were evaluated for hospitalizations, ambulatory care visits, and prescriptions, in subjects who received AIT versus in matched controls with allergic rhinitis who had not received AIT, as well as for SCIT and SLIT tablets. Results: Across all 9 years, the subjects who received AIT had a significantly lower incidence of hospitalization than the controls did. Generally, proportions of subjects with ambulatory care visits and hospitalizations were lower, and length of hospitalization was shorter, for those receiving SLIT tablets than those who received SCIT. Total costs were significantly higher with AIT versus for the controls during the treatment period (years 1 to 3), driven by prescriptions and ambulatory care visits, but they were lower in years 4 to 9. During years 1 to 3, prescription costs were generally higher for SLIT tablets than for SCIT, whereas ambulatory care costs were numerically lower. In most years, hospitalization costs were numerically lower for SLIT tablets than for SCIT. Conclusion: Initial higher HRU and costs of AIT during the expected treatment period are offset in the long term. At-home administration of SLIT tablets may further reduce ambulatory care costs.

Airway hyperresponsiveness correlates with airway TSLP in asthma independent of eosinophilic inflammation.

BACKGROUND: Thymic stromal lymphopoietin (TSLP) is released from the airway epithelium in response to various environmental triggers, inducing a type-2 inflammatory response, and is associated with airway inflammation, airway hyperresponsiveness (AHR), and exacerbations. TSLP may also induce AHR via a direct effect on airway smooth muscle and mast cells, independently of type-2 inflammation, although association between airway TSLP and AHR across asthma phenotypes has been described sparsely. OBJECTIVES: This study sought to investigate the association between AHR and levels of TSLP in serum, sputum, and bronchoalveolar lavage in patients with asthma with and without type-2 inflammation. METHODS: A novel ultrasensitive assay was used to measure levels of TSLP in patients with asthma (serum, n = 182; sputum, n = 81; bronchoalveolar lavage, n = 85) and healthy controls (serum, n = 47). The distribution and association among airway and systemic TSLP, measures of AHR, type-2 inflammation, and severity of disease were assessed. RESULTS: TSLP in sputum was associated with AHR independently of levels of eosinophils and fractional exhaled nitric oxide (ρ = 0.49, P = .005). Serum TSLP was higher in both eosinophil-high and eosinophil-low asthma compared to healthy controls: geometric mean: 1600 fg/mL (95% CI: 1468-1744 fg/mL) and 1294 fg/mL (95% CI: 1167-1435 fg/mL) versus 846 fg/mL (95% CI: 661-1082 fg/mL), but did not correlate with the level of AHR. Increasing age, male sex, and eosinophils in blood were associated with higher levels of TSLP in serum, whereas lung function, inhaled corticosteroid dose, and symptom score were not. CONCLUSIONS: The association between TSLP in sputum and AHR to mannitol irrespective of markers of type-2 inflammation further supports a role of TSLP in AHR that is partially independent of eosinophilic inflammation.

Tobacco Exposure and Efficacy of Biologic Therapy in Patients With Severe Asthma: A Nationwide Study From the Danish Severe Asthma Register.

BACKGROUND: Randomized trials of biologics in severe, uncontrolled asthma have excluded patients with a cumulative tobacco exposure of more than 10 pack-years. Therefore, our knowledge of the impact of smoking exposure on the clinical effects of biologics in severe asthma remains incomplete. However, because many patients with asthma are current or former smokers, investigating the potential impacts of tobacco exposure on the effects of biologic treatment is clinically important. OBJECTIVE: To investigate the impact of smoking history and tobacco exposure on the effectiveness of biologic therapy in real-life patients with severe asthma. METHODS: We used data from a complete nationwide cohort of patients with severe asthma who were receiving biologics, the Danish Severe Asthma Register. We divided patients according to smoking history and cumulative tobacco exposure and analyzed data at baseline and after 12 months of biologic treatment. RESULTS: A total of 724 bio-naive patients were identified in the Danish Severe Asthma Register, 398 of whom had never been smokers (55%), 316 were previous smokers (44%), and 10 were current smokers (1%). Within the group of current and former smokers, 37% had 1 to 9 pack-years of tobacco exposure, 26% had 10 to 19 pack-years, and 37% had 20 or more pack-years of tobacco exposure. Patients with tobacco exposure had similar reductions in the number of exacerbations, reductions in maintenance oral corticosteroid use, and improvements in asthma symptoms compared with patients with 0 pack-years. CONCLUSION: Former smoking history and lifetime tobacco exposure do not have an impact on the efficacy of biologics in patients with severe asthma.

Clinical Response and Remission in Patients With Severe Asthma Treated With Biologic Therapies.

BACKGROUND: The development of novel targeted biologic therapies for severe asthma has provided an opportunity to consider remission as a new treatment goal. RESEARCH QUESTION: How many patients with severe asthma treated with biologic therapy achieve clinical remission, and what predicts response to treatment? STUDY DESIGN AND METHODS: The Danish Severe Asthma Register is a nationwide cohort including all adult patients receiving biologic therapy for severe asthma in Denmark. This observational cohort study defined "clinical response" to treatment following 12 months as a ≥ 50% reduction in exacerbations and/or a ≥ 50% reduction in maintenance oral corticosteroid dose, if required. "Clinical remission" was defined by cessation of exacerbations and maintenance oral corticosteroids, as well as a normalization of lung function (FEV1 > 80%) and a six-question Asthma Control Questionnaire score ≤ 1.5 following 12 months of treatment. RESULTS: Following 12 months of treatment, 104 (21%) of 501 biologic-naive patients had no response to treatment, and 397 (79%) had a clinical response. Among the latter, 97 (24%) fulfilled the study criteria of clinical remission, corresponding to 19% of the entire population. Remission was predicted by shorter duration of disease and lower BMI in the entire population of patients treated with biologic therapy. INTERPRETATION: Clinical response was achieved in most adult patients initiating biologic therapy, and clinical remission was observed in 19% of the patients following 12 months of treatment. Further studies are required to assess the long-term outcome of achieving clinical remission with biologic therapy.

Impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in patients with severe asthma.

BACKGROUND: There is little agreement on clinically useful criteria for identifying real-world responders to biologic treatments for asthma. OBJECTIVE: To investigate the impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in adults with severe asthma. METHODS: This was a longitudinal, cohort study across 22 countries participating in the International Severe Asthma Registry (https://isaregistries.org/) between May 2017 and January 2023. Change in 4 asthma domains (exacerbation rate, asthma control, long-term oral corticosteroid [LTOCS] dose, and lung function) was assessed from biologic initiation to 1 year post-treatment (minimum 24 weeks). Pre- to post-biologic changes for responders and nonresponders were described along a categorical gradient for each domain derived from pre-biologic distributions (exacerbation rate: 0 to 6+/y; asthma control: well controlled to uncontrolled; LTOCS: 0 to >30 mg/d; percent-predicted forced expiratory volume in 1 second [ppFEV1]: <50% to ≥80%). RESULTS: Percentage of biologic responders (ie, those with a category improvement pre- to post-biologic) varied by domain and increased with greater pre-biologic impairment, increasing from 70.2% to 90.0% for exacerbation rate, 46.3% to 52.3% for asthma control, 31.1% to 58.5% for LTOCS daily dose, and 35.8% to 50.6% for ppFEV1. The proportion of patients having improvement post-biologic tended to be greater for anti-IL-5/5R compared with for anti-IgE for exacerbation, asthma control, and ppFEV1 domains, irrespective of pre-biologic impairment. CONCLUSION: Our results provide realistic outcome-specific post-biologic expectations for both physicians and patients, will be foundational to inform future work on a multidimensional approach to define and assess biologic responders and response, and may enhance appropriate patient selection for biologic therapies. TRIAL REGISTRATION: The ISAR database has ethical approval from the Anonymous Data Ethics Protocols and Transparency (ADEPT) committee (ADEPT0218) and is registered with the European Union Electronic Register of Post-Authorization studies (ENCEPP/DSPP/23720). The study was designed, implemented, and reported in compliance with the European Network Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP) Code of Conduct (EUPAS38288) and with all applicable local and international laws and regulation, and registered with ENCEPP (https://www.encepp.eu/encepp/viewResource.htm?id=38289). Governance was provided by ADEPT (registration number: ADEPT1220).

COVID-19 vaccination acceptance, safety and side-effects in European patients with severe asthma.

Background: Vaccination is vital for achieving population immunity to severe acute respiratory syndrome coronavirus 2, but vaccination hesitancy presents a threat to achieving widespread immunity. Vaccine acceptance in chronic potentially immunosuppressed patients is largely unclear, especially in patients with asthma. The aim of this study was to investigate the vaccination experience in people with severe asthma. Methods: Questionnaires about vaccination beliefs (including the Vaccination Attitudes Examination (VAX) scale, a measure of vaccination hesitancy-related beliefs), vaccination side-effects, asthma control and overall safety perceptions following coronavirus disease 2019 (COVID-19) vaccination were sent to patients with severe asthma in 12 European countries between May and June 2021. Results: 660 participants returned completed questionnaires (87.4% response rate). Of these, 88% stated that they had been, or intended to be, vaccinated, 9.5% were undecided/hesitant and 3% had refused vaccination. Patients who hesitated or refused vaccination had more negative beliefs towards vaccination. Most patients reported mild (48.2%) or no side-effects (43.8%). Patients reporting severe side-effects (5.7%) had more negative beliefs. Most patients (88.8%) reported no change in asthma symptoms after vaccination, while 2.4% reported an improvement, 5.3% a slight deterioration and 1.2% a considerable deterioration. Almost all vaccinated (98%) patients would recommend vaccination to other severe asthma patients. Conclusions: Uptake of vaccination in patients with severe asthma in Europe was high, with a small minority refusing vaccination. Beliefs predicted vaccination behaviour and side-effects. Vaccination had little impact on asthma control. Our findings in people with severe asthma support the broad message that COVID-19 vaccination is safe and well tolerated.

Bronchiectasis in severe asthma is associated with eosinophilic airway inflammation and activation.

Background: Bronchiectasis is a common comorbidity in severe asthma; causative pathogenic mechanisms are not fully understood but may differ from other causes of bronchiectasis. The role of eosinophilic airway inflammation, a classic feature of asthma predominantly driven by IL-5 and IL-13, in bronchiectasis is unclear, but association with disruption of the airway epithelium through eosinophil degranulation and increased mucus production is plausible. Objective: We sought to describe the prevalence of bronchiectasis in an unselected population of patients with severe asthma, and the association with the airway eosinophilic inflammation and activation. Methods: All patients with severe asthma according to European Respiratory Society/American Thoracic Society criteria (high-dose inhaled corticosteroids/oral corticosteroids), attending 4 respiratory clinics over a 1-year period, were included. All patients underwent high-resolution computed tomography and induced sputum was collected and analyzed for a cell differential count, free eosinophilic granules, and airway messenger RNA expression of T2 inflammatory pathways. Results: Bronchiectasis was present in 31% (34 of 108) of patients with severe asthma, and half (52%) of these patients had airway eosinophilia whereas only 16% of patients without bronchiectasis had airway eosinophilia. Patients with bronchiectasis had a significantly higher sputum eosinophil count (5.3 vs 0.8; P = .001) as well as more extensive eosinophil degranulation, compared with those without bronchiectasis (13% vs 2%; P = .05), suggesting a higher degree of eosinophil activation. Pairwise analyses identified significantly higher messenger RNA expression of Charcot-Leyden crystal galectin in patients with bronchiectasis (P = .02). Conclusions: Bronchiectasis in severe asthma was associated with eosinophilic airway inflammation and eosinophilic degranulation as well as messenger RNA expression of Charcot-Leyden crystal galectin.

Adult Severe Asthma Registries: A Global and Growing Inventory.

Aim: The International Severe Asthma Registry (ISAR; http://isaregistries.org/) uses standardised variables to enable multi-country and adequately powered research in severe asthma. This study aims to look at the data countries within ISAR and non-ISAR countries reported collecting that enable global research that support individual country interests. Methods: Registries were identified by online searches and approaching severe asthma experts. Participating registries provided data collection specifications or confirmed variables collected. Core variables (results from ISAR's Delphi study), steroid-related comorbidity variables, biologic safety variables (serious infection, anaphylaxis, and cancer), COVID-19 variables and additional variables (not belonging to the aforementioned categories) that registries reported collecting were summarised. Results: Of the 37 registries identified, 26 were ISAR affiliates and 11 non-ISAR affiliates. Twenty-five ISAR-registries and 4 non-ISAR registries reported collecting >90% of the 65 core variables. Twenty-three registries reported collecting all optional steroid-related comorbidity variables. Twenty-nine registries reported collecting all optional safety variables. Ten registries reported collecting COVID-19 variables. Twenty-four registries reported collecting additional variables including data from asthma questionnaires (10 Asthma Control Questionnaire, 20 Asthma Control Test, 11 Asthma Quality of Life Questionnaire, and 4 EuroQol 5-dimension 5-level Questionnaire). Eight registries are linked to databases such as electronic medical records and national claims or disease databases. Conclusion: Standardised data collection has enabled individual severe asthma registries to collect unified data and increase statistical power for severe asthma research irrespective of ISAR affiliations.

Severe asthma trajectories in adults: findings from the NORDSTAR cohort.

BACKGROUND: There is limited evidence on the pathways leading to severe asthma and we are presently unable to effectively predict the progression of the disease. We aimed to describe the longitudinal trajectories leading to severe asthma and to describe clinical events preceding disease progression in a nationwide population of patients with severe asthma. METHODS: We conducted an observational study based on Swedish data from the NORdic Dataset for aSThmA Research (NORDSTAR) research collaboration platform. We identified adult patients with severe asthma in 2018 according to the European Respiratory Society/American Thoracic Society definition and used latent class analysis to identify trajectories of asthma severity over a 10-year retrospective period from 2018. RESULTS: Among 169 128 asthma patients, we identified 4543 severe asthma patients. We identified four trajectories of severe asthma that were labelled as: trajectory 1 "consistently severe asthma" (n=389 (8.6%)), trajectory 2 "gradual onset severe asthma" (n=942 (20.7%)), trajectory 3 "intermittent severe asthma" (n=1685 (37.1%)) and trajectory 4 "sudden onset severe asthma" (n=1527 (33.6%)). "Consistently severe asthma" had a higher daily inhaled corticosteroid dose and more prevalent osteoporosis compared with the other trajectories. Patients with "gradual onset severe asthma" and "sudden onset severe asthma" developed type 2-related comorbidities concomitantly with development of severe asthma. In the latter group, this primarily occurred within 1-3 years preceding onset of severe asthma. CONCLUSIONS: Four distinct trajectories of severe asthma were identified illustrating different patterns of progression of asthma severity. This may eventually enable the development of better preventive management strategies in severe asthma.

Mast Cell Tryptase Promotes Airway Remodeling by Inducing Anti-Apoptotic and Cell Growth Properties in Human Alveolar and Bronchial Epithelial Cells.

Bronchial and alveolar remodeling and impaired epithelial function are characteristics of chronic respiratory diseases. In these patients, an increased number of mast cells (MCs) positive for serine proteases, tryptase and chymase, infiltrate the epithelium and alveolar parenchyma. However, little is known regarding the implication of intraepithelial MCs on the local environment, such as epithelial cell function and properties. In this study, we investigated whether MC tryptase is involved in bronchial and alveolar remodeling and the mechanisms of regulation during inflammation. Using novel holographic live cell imaging, we found that MC tryptase enhanced human bronchial and alveolar epithelial cell growth and shortened the cell division intervals. The elevated cell growth induced by tryptase remained in a pro-inflammatory state. Tryptase also increased the expression of the anti-apoptotic protein BIRC3, as well as growth factor release in epithelial cells. Thus, our data imply that the intraepithelial and alveolar MC release of tryptase may play a critical role in disturbing bronchial epithelial and alveolar homeostasis by altering cell growth-death regulation.