Inhaled steroid inhibits development of total and mite IgE

Endotyping Chronic Respiratory Diseases: T2 Inflammation in the United Airways Model

Over the past 15 years, the paradigm of viewing the upper and lower airways as a unified system has progressively shifted the approach to chronic respiratory diseases (CRDs). As the global prevalence of CRDs continues to increase, it becomes evident that acknowledging the presence of airway pathology as an integrated entity could profoundly impact healthcare resource allocation and guide the implementation of pharmacological and rehabilitation strategies. In the era of precision medicine, endotyping has emerged as another novel approach to CRDs, whereby pathologies are categorized into distinct subtypes based on specific molecular mechanisms. This has contributed to the growing acknowledgment of a group of conditions that, in both the upper and lower airways, share a common type 2 (T2) inflammatory signature. These diverse pathologies, ranging from allergic rhinitis to severe asthma, frequently coexist and share diagnostic and prognostic biomarkers, as well as therapeutic strategies targeting common molecular pathways. Thus, T2 inflammation may serve as a unifying endotypic trait for the upper and lower airways, reinforcing the practical significance of the united airways model. This review aims to summarize the literature on the role of T2 inflammation in major CRDs, emphasizing the value of common biomarkers and integrated treatment strategies targeting shared molecular mechanisms.

Dry Powder and Budesonide Inhalation Suspension Deposition Rates in Asthmatic Airway-Obstruction Regions

Steroid inhalation is the standard bronchial asthma therapy and it includes powdered metered doses, dry powder, and nebulizer suspension. However, particle sizes vary widely. The research goal was to demonstrate that different budesonide administration forms and devices have various deposition rates in the airway obstruction region. Here, we compared relative inhalation therapy efficacies and identified therapies that delivered the highest drug doses to the airway obstruction region. Weibel's anatomy data were used to identify the airway obstruction region in asthma. Based on European Standardization Committee data, we investigated the diameters of the drug particles being deposited there and evaluated the average particle size and distribution of the budesonide dosage forms and application devices. Drug dose depositions were measured by HPLC at each stage of a Cascade Impactor. Weibel's anatomy data indicated that the 1^st–4^th bronchial generations comprised the airway obstruction region and corresponded to the tracheobronchial area. According to the European Standardization, particles 2–6 µm in diameter were readily deposited there. The proportions of particles in this size range were 33.0%, 32.0%, 59.0%, and 78.0% for Turbuhaler, Symbicort, mesh-type NE-U22 suspension, and jet-type NE-C28 suspension, respectively. We localized the airway obstruction regions of bronchial asthma and identified the optimal inhalation therapy particle size. An electric nebulizer was more efficacious for budesonide administration than dry powder delivery. The NE-C28 treatment deposited 2.36x more budesonide in the airway obstruction region than dry powder delivery systems.