nCor a9 Hazelnut / memory protein (f440)1575
Cor a9 is a heat-stable storage protein of the 11S globulin family found in hazelnut (Corylus avellana). The molecular weight of the allergen component is 40 kDa. Sensitization to Cor a9 is common in Central, Southern, and Northwestern Europe, as well as in the USA, with higher IgE reactivity in children. Cor a9 can cause primary sensitization to hazelnut and is associated with severe allergic reactions, including anaphylaxis. Determining specific immunoglobulin E to Cor a9 helps predict clinical hazelnut allergy and differentiate sensitization from allergy. Combined analysis of Cor a9 and Cor a14 increases diagnostic accuracy.
FEIA (Fluorescence Enzyme Immunoassay, ImmunoCAP (Solid-phase Immunofluorescence)) – quantitative determination.
- Diagnosis of allergic reactions to hazelnut.
- Assessment of sensitization level and risk of developing allergic reactions.
- Monitoring therapy effectiveness.
- Assessment of sensitization level after allergen avoidance.
- Evaluation of immune system status.
- Blood sampling in the morning on an empty stomach or 4 hours after eating.
- Drinking plain still water is allowed.
- No smoking for 30 minutes before the test.
- For children under 1 year – no food 30-40 minutes before the test; for children 1-5 years – 2-3 hours fasting.
Cor a9 is a heat-stable storage protein that can cause severe allergic reactions. There is clinical cross-reactivity with other 11S globulins, particularly walnut, mustard, and cashew. Determining Cor a9 helps differentiate allergies and predict their severity. High homology with other allergens does not always mean clinical cross-reactivity, which is important to consider during diagnosis.