Are Inhaled Steroids Friend or Foe? A Large-Scale Study Brings New Insights to the Treatment of Bronchiectasis
Introduction: Re-examining an Old Problem in "Bronchiectasis" Treatment
For many patients with a chronic cough and year-round phlegm, "bronchiectasis" is a long-term respiratory disease that troubles them. It is a chronic disease caused by the permanent "widening" of the airways. Patients not only have to endure endless coughing and phlegm but are also often miserable due to recurrent lung infections. In treatment, doctors often use a type of drug called 'inhaled corticosteroids' (ICS), which is what we often call inhaled steroids. It is a "sharp weapon" against inflammation in diseases such as asthma and COPD. However, for patients with bronchiectasis, the mainstream view has always been that ICS should not be used routinely unless there are comorbidities such as asthma. Recently, a large-scale study published in the prestigious journal Thorax has posed a new challenge to this traditional view and brought new hope to some patients with bronchiectasis.
Research Background: Why is the Use of Inhaled Steroids Not Recommended for Bronchiectasis Treatment?
To understand the importance of this study, we first need to know why the guidelines do not recommend the use of ICS for patients with bronchiectasis alone. The core problem of bronchiectasis is the permanent destruction of the airway structure and chronic inflammation. This inflammation is different from that of asthma; it is mainly driven by a type of white blood cell called 'neutrophils,' and this type of inflammation is inherently less sensitive to steroid treatment. More importantly, some studies have worried that ICS, as an immunosuppressant, may increase the already high risk of lung infections in patients with bronchiectasis. Therefore, several authoritative guidelines, including the European Respiratory Society, have clearly recommended that ICS should only be considered for patients with bronchiectasis who also have asthma, COPD, or allergic bronchopulmonary aspergillosis (ABPA). But what is the actual use of ICS in clinical practice? Is it really ineffective or harmful for all patients with bronchiectasis alone? These questions have long lacked the support of large-scale data.
Key Findings: Revealing the Widespread "Off-Label Use" and Unexpected Benefits for a Specific Population
This analysis, based on the European Bronchiectasis Registry (EMBARC), included more than 19,000 patients with bronchiectasis from 31 countries and is one of the largest studies in this field to date.
Finding One: The use of ICS is extremely common, far exceeding the scope recommended by the guidelines. The study found that as many as 52.3% of patients with bronchiectasis were using ICS. Even after excluding those patients with clear indications for medication, such as coexisting asthma or COPD, nearly one-third (32.7%) of "pure" bronchiectasis patients were still using ICS. This indicates that there is a huge gap between clinical practice and the guideline recommendations.
Finding Two: For most patients, ICS did not reduce acute exacerbations. Overall, patients who used ICS did not experience fewer acute exacerbations (i.e., the need for antibiotics due to worsening respiratory symptoms) or hospitalizations during the follow-up period than those who did not. This seems to confirm the cautious attitude of the guidelines.
Finding Three: A key breakthrough—patients with high eosinophil counts benefited significantly. The most striking finding of the study was that in a special subgroup, ICS showed a clear protective effect. For those patients with bronchiectasis who had elevated levels of "eosinophils" (another type of white blood cell) in their blood (and no other diseases such as asthma), the frequency of acute exacerbations was significantly reduced by 30% (hazard ratio of 0.70) after using ICS. This suggests that bronchiectasis is not a "monolithic" disease, and there may be an "eosinophilic subtype" that is sensitive to steroid treatment.
Brief Description of Research Methods
This was a large-scale, multi-center observational study. The researchers collected data from patients registered on the European Bronchiectasis Registry (EMBARC) from 2015 to 2022. By analyzing these real-world clinical data, the researchers compared the differences in baseline clinical characteristics between patients who used and did not use ICS and followed them for up to 5 years to observe long-term outcomes such as acute exacerbations, hospitalizations, and mortality.
Limitations and Outlook of the Study
It should be emphasized that this study is an observational study, which reveals a "correlation" rather than a "causal relationship." That is, we observed that the use of ICS in patients with high eosinophil counts is associated with a reduction in acute exacerbations, but we cannot be 100% certain that ICS directly caused this result. The researchers also pointed out that patients who use ICS are generally sicker, which may affect the interpretation of the results. Therefore, the final confirmation of this finding will require a well-designed randomized controlled trial (RCT). Nevertheless, the significance of this study is still great. It is the first to confirm, in a large population, the potential of using a biomarker (eosinophil level) to screen for patients with bronchiectasis who may benefit from ICS treatment. This opens a window for the future realization of "individualized treatment" or "precision medicine" for bronchiectasis.
Summary: Moving Toward More Precise Treatment for Bronchiectasis
In conclusion, this study tells us two important things: first, the use of inhaled steroids is very common in the treatment of bronchiectasis, and there is even a situation of overuse; second, for that specific group of patients with high levels of eosinophils in their blood, inhaled steroids may no longer be a "forbidden zone" but may be an effective tool for reducing acute exacerbations. In the future, with a simple blood test, doctors may be able to more accurately determine which patients with bronchiectasis can truly benefit from inhaled steroid treatment, thereby avoiding unnecessary medication risks and achieving safer and more effective individualized management.
References
- Pollock J, Polverino E, Dhar R, et al. Use of inhaled corticosteroids in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC). Thorax. Published Online First: 29 May 2024. doi: 10.1136/thorax-2024-221650.
