Austrian Severe Asthma Registry Shows Improved Control and Lung Function

A prospective registry study conducted in Austria has documented significant improvements in asthma control and lung function among patients with severe asthma over a two-year follow-up period. The research, published in the journal Heliyon in November 2026, analyzed data from the German Asthma Net (GAN) Severe Asthma Registry, focusing specifically on patients enrolled at Austrian centers. The study aimed to assess changes in clinical outcomes and pulmonary function during annual follow-up visits, providing a real-life perspective that complements the findings of randomized controlled trials, which often fail to reflect the broader severe asthma population due to strict eligibility criteria.

The study included 214 severe asthma patients from six Austrian centers, with baseline data collected between 2013 and 2022. To be included in the registry, patients were required to have a confirmed diagnosis of severe asthma as defined by the European Respiratory Society and American Thoracic Society criteria, diagnosed by a respiratory specialist. At the time of baseline assessment, the cohort consisted of 47.2% female patients with a mean age of 53.7 years. The median Asthma Control Test (ACT) score at baseline was 17, indicating that only a third of the patients had asthma control classified as well controlled based on Global Initiative for Asthma (GINA) criteria. Additionally, the mean forced expiratory volume in one second (FEV1) was 61.9% of the predicted value, reflecting significant impairment in lung function at the start of the observation period.

Longitudinal follow-up data were available for 130 patients at year 1 and 91 patients at year 2. The researchers noted that the decrease in patient numbers at subsequent visits was not due to treatment discontinuation or loss to follow-up, but rather due to the continuous enrollment of new patients in the registry. A comparison of key clinical parameters at baseline between patients with and without available year 1 visits showed no significant differences, suggesting that the subset of patients with complete follow-up data was representative of the broader cohort. This design allows for a meaningful assessment of clinical trajectories within the severe asthma population.

The primary findings indicated that all follow-up visits in years 1 and 2 showed an increase in mean FEV1 compared to baseline. The improvements were statistically significant and clinically relevant, exceeding the highest threshold for minimal clinically important difference commonly used for patients with asthma. Specifically, FEV1 increased by 265 mL at year 1 and by 251 mL at year 2, with both changes showing a p-value of less than .001. Furthermore, FEV1 percent predicted showed persistent improvement after the baseline visit in both years 1 and 2, reinforcing the observation of enhanced pulmonary function over time.

Asthma control scores also demonstrated substantial improvements. Both the median ACT and the Asthma Control Questionnaire 5-item scale (ACQ-5) improved well beyond their respective minimal clinically important differences. The ACT score increased by 4 points and the ACQ-5 score decreased by 1.6 points at year 1, with similar magnitudes of improvement observed at year 2. All these changes were statistically significant with p-values less than .001. Notably, the dose of inhaled corticosteroids (ICS) did not change between the baseline visit and the follow-up visits, with the median daily beclometasone equivalent remaining at 1000 mcg. This suggests that the observed improvements in asthma control and lung function were not driven by an escalation of standard inhaled therapy.

The study also examined the role of monoclonal antibody treatments, which are biologic therapies targeted at specific inflammatory pathways in severe asthma. The use of severe asthma monoclonal antibody treatment increased from 60.7% at the baseline visit to 71.8% at year 1 and 73.9% at year 2. The most commonly used agents included omalizumab, benralizumab, and mepolizumab. The vast majority of patients who received a monoclonal antibody at baseline continued with the same treatment through the follow-up visits, with the exception of those receiving reslizumab, many of whom switched to other biologic treatments, likely due to easier subcutaneous administration. No patients stopped a biologic without switching to another until the end of data collection.

When analyzing only patients who did not receive any monoclonal antibody at baseline or at visit year 1, there was no significant change in ACT or FEV1 between those visits. This finding highlights the potential contribution of biologic therapies to the overall improvements observed in the cohort. The researchers observed an association between clinical improvement in both asthma control and pulmonary function and the increased rate of monoclonal antibody treatments. However, the study design does not allow for the isolation of the specific causal effect of biologics, as improvements may also be attributed to the optimization of basic asthma treatment through regular check-ups and monitoring at specialized centers.

The study further investigated the effect of a measurable Type 2 (T2) inflammatory signal on follow-up outcomes. A measurable T2 signal was defined as a fraction of exhaled nitric oxide of 20 ppb or higher and/or a peripheral blood eosinophilic count of 150 cells/μl or higher. A two-way mixed-method analysis of variance revealed no statistically significant interaction between changes in ACT or FEV1 from baseline to year 1 and the presence of a measurable T2 signal at baseline. This suggests that the presence or absence of a T2 signal at the time of enrollment did not significantly predict the magnitude of clinical improvement in this cohort.

Smoking status was also analyzed for its impact on follow-up outcomes. There was a statistically significant interaction between changes in ACT from baseline to year 1 and smoking status. While both never-smokers and ex-smokers showed statistically significant improvements in asthma control, only never-smokers exceeded the threshold of minimal clinical significance. The median ACT in never-smokers improved from 17 to 23.5, whereas in ex-smokers it improved from 17 to 19. There was no statistically significant interaction between changes in FEV1 and smoking status, and no relevant difference in monoclonal antibody use was found between the never-smoker and ex-smoker groups that could explain this interaction.

The concept of remission in severe asthma, often associated with the use of monoclonal antibodies, was also evaluated. Remission was defined as an ACT score of at least 20, no exacerbations in the preceding 12 months, and no daily oral corticosteroids. At baseline, 9.3% of patients fulfilled these criteria. This rate increased significantly to 31.5% at year 1 and 46.2% at year 2. However, the stability of this remission status was variable; 20% of patients who met remission criteria at year 1 did not fulfill them at year 2. This variability suggests that the clinical state of remission may not be as stable as the term implies, potentially due to the variable natural course of the disease, waning efficacy of biologics over time, or the limitations of using short-term patient-reported outcomes like the ACT to define long-term remission.

The study has several limitations that must be considered when interpreting the results. First, while a majority of centers treating severe asthma in Austria are part of the GAN registry, the data does not account for patients who were never referred to a specialized center. Second, the study design lacks a control group, making it difficult to definitively attribute improvements to specific interventions. Additionally, information on medication adherence and inhaler technique accuracy was not available, which are critical factors in asthma management. Despite these limitations, the study is strengthened by the high quality of data collection, with few missing data points and prospective evaluation of every patient by severe asthma experts at every visit.

This research provides the first Austria-wide longitudinal investigation of severe asthma patients, offering valuable insights into the real-world outcomes of this difficult-to-treat condition. The findings indicate that asthma control and lung function can improve significantly over time in a registry setting, potentially driven by the increased use of monoclonal antibodies and optimized specialist care. The data underscores the importance of continuous monitoring and the potential benefits of biologic therapies in managing severe asthma, while also highlighting the need for further research to understand the long-term stability of remission and the specific contributions of different treatment modalities.

Subject of Research: Longitudinal analysis of asthma control and lung function in Austrian severe asthma patients

Article Title: Asthma control improves in Austrian severe asthma patients

Article References: Renner, A., Stoshikj, S., Pohl, W., Bal, C., Löffler-Ragg, J., Reisinger, M., Buhl, R., Hamelmann, E., Taube, C., Korn, S., & Idzko, M. (2026). Asthma control improves in Austrian severe asthma patients. Heliyon, 12(16), Article e45695. https://doi.org/10.1016/j.heliyon.2026.e45695

Image Credits: AI Generated

DOI: 10.1016/j.heliyon.2026.e45695

Keywords: severe asthma, asthma control, monoclonal antibodies, lung function, registry study, Austria, biologic therapy, FEV1, ACT score, remission, Asthma, control