Alternaria alternata allergens

Alternaria alternata allergens represent a group of proteins produced by the ubiquitous mold Alternaria alternata, which is a significant environmental trigger for respiratory allergies and severe asthma. The primary component, Alt a 1, is an acidic glycoprotein of unknown precise biological function but serves as a major clinical marker for sensitization, being recognized by over 80% of mold-allergic individuals [Gabriel MF, et al., 2016; PMID: 26868516]. Other allergens in this group include enzymes like Alt a 4 (enolase) and Alt a 6 (enolase), which can lead to cross-reactivity with other fungal species [Simon-Nobbe B, et al., 2008; PMID: 18181216]. These allergens interact with the human immune system by binding to specific IgE on mast cells and basophils, leading to mediator release and allergic symptoms. In a therapeutic context, they are the active constituents of allergen-specific immunotherapy (AIT), where controlled exposure to standardized extracts aims to induce immunological tolerance, shift T-cell responses from Th2 to Th1/Treg, and promote the production of blocking IgG4 antibodies [WHO/IUIS Allergen Nomenclature, 2024]. Exposure to these allergens is highly associated with asthma exacerbations and chronic rhinosinusitis, making them critical targets for diagnostic and desensitization strategies.

Other names

Alt a allergensBlack mold allergensAlternaria rot allergensAlt a 1Alt a 2Alt a 3Alt a 4Alt a 5Alt a 6Alt a 7Alt a 8Alt a 10Alt a 12Alt a 13Alt a 14Alt a 15

Allergen-specific immunotherapy (AIT) involves the repeated administration of allergen extracts to induce peripheral T-cell tolerance, increase the activity of regulatory T cells (Tregs), and stimulate the production of allergen-specific IgG4 antibodies that compete with IgE for allergen binding, thereby preventing mast cell degranulation.