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.