7. SUMMARY:
Bronchial asthma is more like a complex group of clinical diseases than a single disease. The core importance of airway epithelium in asthma is now widely accepted. The airway epithelium constitutes an important barrier at the interface between the external environment and the lung. A disordered barrier allows allergens to enter the body and trigger a sensitization reaction, which is the starting point of allergic asthma. A variety of factors that induce AEC damage and dysfunction are also initiating factors in asthma. This overlap highlights the key role of these cells in asthmatic airway inflammation, airway hyperresponsiveness, airway remodeling, and airway mucus hypersecretion. Compared with healthy individuals, the epithelium of asthma patients shows several structural and functional abnormalities, which provides important mechanistic insight into how asthma is initiated and perpetuated and could provide a framework by which to select new therapeutic strategies that prevent exacerbations and alter the natural course of the disease. In addition, the study of asthma susceptibility genes and epigenetic regulatory mechanisms reveals the key role of AECs in asthma.
Asthma has great heterogeneity in etiology, triggers, clinical characteristics, and response to treatment indicating that identifying asthma patients with different phenotypes and endotypes is of great significance for accurate diagnosis and treatment. At present, the clinical treatment mainly adopts a step-by-step symptom-based approach, which is derived from a simplified view of asthma and the heterogeneity of asthma is not recognized at the clinical and molecular levels. At the same time, the emergence of expensive targeted monoclonal therapies has further prompted the expansion of research on asthma biomarkers. In view of the key role of airway epithelium in the occurrence, development and worsening of asthma, it has become a research hotspot. The development of new serum/sputum biomarker panels with higher sensitivity and specificity may lead to rapid more-accurate diagnosis of asthma subtypes. This will identify patients who may benefit from novel epithelial-focused therapies and find new therapeutic strategies targeted to correct dysregulated epithelial barrier.
The evaluation value of a single biomarker is also transformed into a combination of various markers. It is likely that combinations of analytes derived from different “omics” approaches may provide a better biomarker panel to indicate epithelial damage in asthma prior to any changes that may be detectable by enhanced imaging capabilities. Combining biomarkers with clinical parameters and new information from the fields of genomics, transcriptomics and proteomics, will further promote our understanding of AECs in asthma.