Cashew allergen (Ana o)

Cashew allergens are a group of highly stable seed storage proteins derived from the cashew nut (Anacardium occidentale) that serve as potent antigens, triggering IgE-mediated hypersensitivity reactions in sensitized individuals (WHO/IUIS Allergen Nomenclature, 2024). The major allergens identified are Ana o 1 (a 7S globulin), Ana o 2 (an 11S globulin), and Ana o 3 (a 2S albumin), with Ana o 3 being the most clinically significant due to its resistance to heat and proteolysis and its strong association with severe systemic anaphylaxis (Robotham et al., 2005). Biologically, these proteins function as nitrogen and carbon reserves for the developing plant embryo, but in the human immune system, they cross-link allergen-specific IgE on the surface of mast cells and basophils, leading to the explosive release of inflammatory mediators (Wangsch et al., 2002). In the pharmaceutical context, these allergens are utilized as the active pharmaceutical ingredients in diagnostic assays and are the focus of experimental oral immunotherapy (OIT) protocols aimed at inducing clinical desensitization (StatPearls, 2023). The therapeutic objective is to modulate the immune system toward a state of tolerance, thereby increasing the threshold of allergen exposure required to trigger a reaction and reducing the risk of life-threatening events.

Other names

Anacardium occidentale allergenAna o 1Ana o 2Ana o 3Cashew nut allergen

Induction of immunological tolerance through allergen-specific immunotherapy (AIT), which promotes the expansion of regulatory T cells (Tregs), increases the production of allergen-specific IgG4 blocking antibodies, and reduces the sensitivity of mast cells and basophils to the allergen (StatPearls, 2023; Robotham et al., 2005).