Respiratory allergens

Respiratory allergens, commonly referred to as aeroallergens, are exogenous proteins or glycoproteins that elicit IgE-mediated hypersensitivity reactions in susceptible individuals (World Allergy Organization, 2024). These allergens originate from various environmental sources, including pollens (trees, grasses, weeds), house dust mites, animal dander, and fungal spores (NIH/NIAID, 2023). Upon inhalation, these molecules are processed by antigen-presenting cells and presented to T-cells, leading to the production of allergen-specific IgE antibodies that sensitize mast cells and basophils (StatPearls, 2023). Subsequent exposure results in the cross-linking of IgE and the release of inflammatory mediators such as histamine and leukotrienes, causing symptoms of allergic rhinitis and asthma (PubMed, PMID: 30204022). While they are not endogenous therapeutic targets, they are the basis for allergen-specific immunotherapy (AIT), which seeks to modify the underlying disease by inducing immune tolerance (JACI, 2017). AIT products, such as sublingual tablets or subcutaneous injections, utilize standardized extracts of these allergens to desensitize the patient's immune system over time (FDA, 2023).

Allergen-specific immunotherapy (AIT) involves the repeated administration of specific allergens to induce immunological tolerance, characterized by the induction of regulatory T and B cells, the production of blocking antibodies (IgG4), and a shift from Th2 to Th1 immune responses (JACI, 2017; PMID: 28065554).