Table 3 Currently used asthma biomarkers
Biomarker | Testing method | Phenotype | Role in allergic pathway | Associated cytokines | Associated biologic agents |
|---|---|---|---|---|---|
IgE | Serum | Allergic (early onset) | Binds to FcεRI on mast cells, basophils, and antigen-presenting dendritic cells Activates the release of inflammatory mediators | IL-4, IL-13 | Omalizumab |
Eosinophil | Blood, sputum | Eosinophilic (late onset)—allergic and non-allergic | Modulates the immune response Promotes airway hyperresponsiveness and remodelling | IL-5 | Mepolizumab, reslizumab, benralizumab |
IL-4, IL-13 | Dupilumab | ||||
Neutrophil | Sputum | Neutrophilic | Significantly associated with severe asthma Accumulates in the airways Prominent in airway secretions during exacerbations | IL-8, IL-17 | |
Surrogate | |||||
Periostin | Serum, sputum | Eosinophilic | Regulates eosinophil recruitment and eosinophilic tissue infiltration Active in Th2 mucosal inflammation, airway remodelling, and expression of inflammatory mediators | IL-4, IL-13 | Lebrikizumab, tralokinumab, omalizumab |
DPP-4 | Serum | Eosinophilic, AERD | Stimulates the proliferation of bronchial smooth muscle cells and human fetal lung fibroblasts Promotes fibronectin production | IL-13 | Tralokinumab |