Sensitization to storage proteins in peanut and hazelnut is associated with higher levels of inflammatory markers in asthma

Abstract

Background: Sensitization to peanuts and hazelnuts is common among young asthmatics and can be primary or a result of cross-reactivity. Sensitization as a result of cross-reactivity to birch pollen is typically associated to tolerance or mild and local symptoms upon intake of peanut or hazelnut. Aim: The aim of this study was to investigate relationships between IgE antibody responses against peanut and hazelnut components, airway and systemic inflammation markers, lung function parameters and reported food hypersensitivity in a cohort of asthmatic children and young adults. Methods: A population of 408 asthmatic individuals aged 10-35 years were investigated. Information on hypersensitivity symptoms upon intake of peanut or hazelnut were recorded in a standardized questionnaire. Fraction of exhaled nitric oxide (FeNO), blood eosinophil count (B-Eos), spirometry, methacholine challenge outcome and IgE antibodies to peanut and hazelnut allergens were measured by standard clinical and laboratory methods. Results: Subjects sensitized to any of the peanut (Ara h 1, 2 or 3) or hazelnut (Cor a 9 or 14) storage proteins were significantly younger (17.6 vs 21.2 years), had higher levels of FeNO (23.2 vs 16.7 ppb) and B-Eos (340 vs 170 cells/ mcl) than those displaying only pollen-related cross-reactive sensitization. Levels of FeNO correlated with levels of IgE to storage proteins in children, but not in adults. Levels of B-Eos correlated with levels of IgE to all allergen components investigated in children, but only to levels of IgE to storage proteins in adults. Anaphylaxis and skin reactions upon intake of peanuts or hazelnuts were more often reported among subjects sensitized to the respective storage proteins than among those with only pollen-related cross-reactive sensitization. As compared to peanut, hazelnut was more often reported to cause gastrointestinal symptoms and less often oral cavity symptoms. Conclusions: Sensitization to peanut and hazelnut storage proteins was associated with higher levels of inflammation markers and food hypersensitivity symptoms in this population of subjects with asthma.

Development of sensitization to peanut and storage proteins and relation to markers of airway and systemic inflammation: A 24‐year follow‐up

“…Storage protein sensitized individuals had higher levels of exhaled nitric oxide and blood eosinophil cell counts as compared to other sensitized individuals, these result is in line with Johnson et al 24 who found that storage protein sensitized individuals showed higher FENO (23.2 p vs. 16.7 ppb) compared with non‐storage protein sensitized and by Hughes et al 23 who found that in individuals with previous asthma or no current medication, the majority still had FENO >35 ppb. However, our findings of elevated FENO in storage protein sensitized individuals independent of asthma and polysensitization is new and has not been shown before.…”

“…22 Both peanut allergic individuals with and without asthma 23 have been found to express high levels of FENO even though peanut is primarily a food and not inhalant allergen. 23,24 Johnson et al have reported that asthmatic patients aged 10-35 years, with a sensitization to peanut allergen molecules Ara h 1, h 2 and h 3 or the hazelnut storage proteins Cor a 9 and Cor a 14, were found to express higher levels of FENO than individuals without peanut sensitization, 24 especially in the youngest age group. The explanation for this is not completely understood, neither if this is a sign of airway inflammation or a systemic inflammation, and further studies are needed.…”

Natural History of Hazelnut Allergy and Current Approach to Its Diagnosis and Treatment

“…This underscores the previous statement that in adults, cross-reactivity between hazelnuts and birch is the main driving force of reported adverse reactions, with these sensitizations being more common in asthma. A recent study [ 49 ] showed that asthmatic individuals between 10 and 35 years of age with coexisting sensitization to peanut and hazelnut SSPs have higher levels of inflammatory markers with higher levels of a fraction of exhaled nitric oxide and blood eosinophil count.…”

Recent advances in diagnosing and managing nut allergies with focus on hazelnuts, walnuts, and cashew nuts

“…Sensitization to hazelnuts is common among young asthmatics 41 and can be a primary effect or a result of cross-reactivity. Johnson et al investigated the relationships between IgE antibody responses to hazelnut components, airway and systemic inflammation markers, and lung function parameters, and reported food hypersensitivity in a study of 408 asthmatic children and young adults in Sweden.…”