Sensitization profiles to hazelnut allergens across the United States

Measurement of IgE antibody to hazelnut components can aid in the prediction of allergic responses to the food.

To investigate the association between patient demographics (age, location) and patterns of allergic sensitization to hazelnut components across the United States and to investigate the degree of correlation between hazelnut sensitization with sensitization to other tree nuts, peanuts, and their components.

Serum samples from 10,503 individuals with hazelnut extract specific IgE (sIgE) levels of 0.35 kU_A/L or higher were analyzed for IgE antibodies to Cor a 1, 8, 9, and 14 by ImmunoCAP. A subset of these patients were analyzed for IgE antibodies to peanut, walnut, and cashew nut IgE along with associated components.

Among hazelnut sensitized individuals, children (<3 years old) were predominantly sensitized to Cor a 9 and Cor a 14. Conversely, Cor a 1 sIgE sensitization was much higher in adults than children, especially in the Northeastern United States. Cor a 8 sensitization was relatively constant (near 10%) across all ages. Cosensitization of hazelnut with other tree nuts and peanuts was related to correlation of IgE concentrations of individual component families.

We conclude that sensitization to individual hazelnut components is highly dependent on age and/or geographic location. Component correlations suggest that cosensitization to hazelnut and walnut may be caused by their pathogenesis-related protein 10 allergens, nonspecific lipid transfer proteins, or seed storage proteins, whereas hazelnut and peanut cosensitization is more often caused by cross-reactivity of pathogenesis-related protein 10 (Cor a 1 and Ara h 8) and nonspecific lipid transfer proteins (Cor a 8 and Ara h 9).