rJug r3 Walnut, LTP (f442)1573
Jug r3 is a nonspecific lipid transfer protein (nsLTP) with a molecular weight of 9 kDa, which is the major allergen component of walnut. It is resistant to heat treatment and pepsin digestion and belongs to the prolamin superfamily. Walnut allergy is common in the USA, France, Germany, Italy, and Spain, with sensitization to Jug r3 mainly in the Mediterranean region. In sensitive patients, serious reactions may occur – contact urticaria, oral allergy syndrome, gastrointestinal disorders, and anaphylaxis. Jug r3 shows cross-reactivity with allergen components of peach (Pru p3), peanut (Ara h9), hazelnut (Cor a8), apricot (Pru ar3), cherry (Pru av3), and almond (Pru du3) due to structural similarity and shared IgE-binding epitopes.
FEIA (Fluorescence Enzyme Immunoassay, ImmunoCAP (Solid-phase Immunofluorescence)) – quantitative determination.
- Diagnosis of allergic reactions to walnut.
- Assessment of sensitization level and risk of allergic reactions.
- Monitoring the effectiveness of ongoing therapy.
- Evaluation of sensitization level after allergen avoidance.
- Assessment of immune system status.
- Blood should be drawn in the morning on an empty stomach or 4 hours after eating.
- Drinking plain still water is allowed.
- Do not smoke for 30 minutes before the test.
- For children under 1 year – no food 30-40 minutes before the test; for children aged 1-5 years – 2-3 hours fasting.
Jug r3 is the major allergen component of walnut that causes severe allergic reactions. It has high cross-reactivity with other LTP allergens, including Cor a8 (hazelnut), Pru av3 (cherry), Ara h9 (peanut), and Pru du3 (almond), confirmed by a significant percentage of amino acid sequence similarity and IgE epitopes. This cross-reactivity can lead to severe allergic symptoms when consuming various plant-based products. It is especially important to consider cross-reactivity between tree nuts and fruits of the Rosaceae family for allergy diagnosis and treatment.