Hazelnut allergen proteins (Cor a)

Hazelnut allergen proteins are a group of proteins from the hazelnut (Corylus avellana) that are responsible for triggering IgE-mediated allergic reactions in humans [1]. These proteins are classified into several distinct families based on their structural and biological properties, including the pathogenesis-related protein family 10 (PR-10), non-specific lipid transfer proteins (nsLTPs), and various seed storage proteins such as 2S albumins and 11S globulins [2][3]. Cor a 1, the major PR-10 allergen, is frequently associated with oral allergy syndrome in patients sensitized to birch pollen due to cross-reactivity with the birch allergen Bet v 1 [4]. Conversely, storage proteins like Cor a 9 and Cor a 14 are highly stable and are often linked to severe, systemic allergic reactions and anaphylaxis [5]. In the context of clinical medicine, these proteins are the primary targets for allergen-specific immunotherapy (AIT), which aims to desensitize patients through controlled, incremental exposure [6]. This therapeutic approach works by modulating the immune system to favor a regulatory T-cell response and the production of IgG4 antibodies, thereby reducing the risk of acute allergic episodes upon accidental ingestion [7].

Other names

Corylus avellana allergensFilbert allergensCor a proteins

Allergen-specific immunotherapy (AIT) involves the repeated administration of hazelnut allergen proteins to induce immunological tolerance. This process shifts the immune response from a Th2-dominated profile (associated with IgE production) to a Th1 and regulatory T-cell (Treg) profile, leading to the production of blocking IgG4 antibodies and reduced mast cell and basophil reactivity [6][7].