Major allergen Bet v 1-A (Bet v 1)

Major allergen Bet v 1-A, widely known as Bet v 1, is the primary sensitizing protein in the pollen of the silver birch tree (Betula pendula). It belongs to the pathogenesis-related protein family 10 (PR-10) and is characterized by a seven-stranded antiparallel beta-sheet and a long C-terminal alpha-helix that forms a large internal hydrophobic cavity (Source: UniProt P15494). Bet v 1 is the clinical driver for over 90% of birch pollen allergies, which manifest as seasonal allergic rhinitis, conjunctivitis, and allergic asthma. It also serves as the archetype for pollen-food allergy syndrome, as its structural similarity to proteins in fruits like apples (Mal d 1) leads to cross-reactive immune responses. From a therapeutic perspective, Bet v 1 is the primary component of allergen-specific immunotherapy (AIT) products such as Itulazax. These therapies aim to modify the underlying disease process by desensitizing the immune system through controlled, repeated exposure to the allergen. This exposure shifts the immune profile from a pro-inflammatory Th2 response to a tolerant state characterized by the production of interleukin-10 and IgG4 antibodies. Monitoring of specific IgE and IgG4 levels is commonly used to assess sensitization and the efficacy of treatment in clinical settings (Source: NIH/NCBI Bookshelf, StatPearls).

Other names

Bet v 1Birch pollen allergen Bet v 1Pathogenesis-related protein family 10 memberBetula pendula allergen 1PR-10 allergen

Allergen-specific immunotherapy (AIT) using Bet v 1 extracts functions by inducing immunological tolerance. This is achieved through the induction of regulatory T cells (Tregs), a shift from Th2 to Th1 immune responses, and the production of allergen-specific IgG4 'blocking antibodies' that compete with IgE for binding to the allergen, thereby preventing mast cell activation (Source: DOI:10.1111/all.13271, PubMed: 28843004).