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Abstract Background Since the last guidance was published by the Canadian Thoracic Society, there have been several advances in the clinical management of severe asthma. To gain a better understanding of the current standards of care and treatment patterns of patients, the CASCADE practice reflective program was established to conduct a real-world analysis of severe asthma management among specialists in Canada with a goal of identifying areas of opportunity to enhance patient management and outcomes. Methods The CASCADE program was a two-part practice reflective and assessment program delivered through an on-line portal for selected specialists (Respirologists and Allergists) in Canada. The program consisted of a one-time overview survey of physician practice to establish overall practice parameters, followed by a review of at least 5 severe asthma patients to establish the current landscape of severe asthma management. Results The program collected practice overview surveys from 78 specialists (52 Respirologists, 24 Allergists, and 2 General practice physicians with an interest in respiratory disease) in 8 provinces. Practices included a variety of types in both large metropolitan centres and smaller regional settings. There were 503 patients reviewed and included in the program. Most (65%) patients were currently using a biologic treatment, 30% were biologic naive, and 5% had used a biologic treatment in the past. Most patients (53%) were reported to have mixed allergic and eosinophilic phenotypes, despite a perception that allergic, eosinophilic and mixed phenotypes were evenly balanced in the physician practice. Overall, patients currently treated with biologic agents had parameters suggesting higher control and were more satisfied with treatment. However, there was less than optimal treatment satisfaction for more than half of all patients, particularly for those patients not treated with a biologic agent. Conclusions Phenotyping is hampered by poor availability for several assessments, and the full range of treatments are not currently fully utilized, partly due to physician familiarity with the agents and partly due to prescribing restrictions. Even when treated with biologic agents, patient satisfaction can still be improved.

Abstract Rationale Severe asthma affects a small proportion of asthmatics but represents a significant healthcare challenge. Bronchial thermoplasty (BT) is an interventional treatment approach preconized for uncontrolled severe asthma after considering biologics therapy. It was showed that BT long-lastingly improves asthma control. These improvements seem to be related to the ability of BT to reduce airway smooth muscle remodeling, reduce the number of nerve fibers and to modulate bronchial epithelium integrity and behavior. Current evidence suggest that BT downregulates epithelial mucins expression, cytokine production and metabolic profile. Despite these observations, biological mechanisms explaining asthma control improvement post-BT are still not well understood. Objectives To assess whether BT affects gene signatures in bronchial epithelial cells (BECs). Methods In this study we evaluated the transcriptome of cultured bronchial epithelial cells (BECs) of severe asthmatics obtained pre- and post-BT treatment using microarrays. We further validated gene and protein expressions in BECs and in bronchial biopsies with immunohistochemistry pre- and post-BT treatment. Measurements and main results Transcriptomics analysis revealed that a large portion of differentially expressed genes (DEG) was involved in anti-viral response, anti-microbial response and pathogen induced cytokine storm signaling pathway. S100A gene family stood out as five members of this family where consistently downregulated post-BT. Further validation revealed that S100A7, S100A8, S100A9 and their receptor (RAGE, TLR4, CD36) expressions were highly enriched in severe asthmatic BECs. Further, these S100A family members were downregulated at the gene and protein levels in BECs and in bronchial biopsies of severe asthmatics post-BT. TLR4 and CD36 protein expression were also reduced in BECs post-BT. Thymic stromal lymphopoietin (TSLP) and human β-defensin 2 (hBD2) were significantly decreased while no significant change was observed in IL-25 and IL-33. Conclusions These data suggest that BT might improve asthma control by downregulating epithelial derived S100A family expression and related downstream signaling pathways.