Walnut and pecan cross-reactive allergens

Walnut and pecan allergens are a group of highly cross-reactive proteins from the Juglandaceae family, primarily comprising seed storage proteins such as 2S albumins (Jug r 1, Car i 1), 7S globulins (Jug r 2, Jug r 6, Car i 2), and 11S globulins (Jug r 4, Car i 4) (nih.gov, researchgate.net). These proteins share significant sequence identity and structural homology, leading to high rates of co-sensitization and clinical cross-reactivity; for instance, Jug r 1 and Car i 1 share approximately 88% sequence identity (nih.gov). Sensitization to these allergens is a major cause of severe food-induced allergic reactions, including life-threatening anaphylaxis, and is typically persistent throughout life (londonallergyconsultants.co.uk, usda.gov). In clinical practice, these allergens serve as targets for component-resolved diagnosis (CRD) to distinguish between primary sensitization and cross-reactivity with other nuts or pollens (thermofisher.com, nih.gov). They are also the primary targets for therapeutic interventions such as oral immunotherapy (OIT) and investigational DNA vaccines, which aim to induce desensitization by shifting the immune response from a Th2-mediated allergic profile to a Th1-mediated tolerant profile (londonallergyconsultants.co.uk, usda.gov). Management of patients sensitized to these allergens requires strict dietary avoidance and the availability of emergency epinephrine (londonallergyconsultants.co.uk, usda.gov).

Other names

Jug r 1Jug r 2Jug r 4Jug r 6Car i 1Car i 2Car i 4Walnut-pecan cross-reactive proteinsJuglandaceae seed storage proteins

Immunotherapy-mediated desensitization, IgE-mediated immune activation, Th2 to Th1 immune response shifting