Component-resolved diagnostics study on nut sensitization and cross-reactivity in China.

PURPOSE: Nut sensitization in China remains insufficiently characterized. Component-resolved diagnosis (CRD) technology offers the ability to distinguish true food allergies from pollen-induced cross-sensitizations while avoiding the risks of oral food challenge (OFC) tests. This study aims to explore and validate the major allergenic components and patterns of cross-reactivity between nuts and pollens in patients with pollen-food allergy syndrome (PFAS).

METHODS

This study evaluated the sensitization profiles of 104 patients with self-reported PFAS, focusing on crude extracts and major allergenic components of pollen and nuts. In addition, the presence of cross-reactive carbohydrate determinants (CCDs) was tested to determine if the specific immunoglobulin E (sIgE) detection of these plant allergens was influenced by non-specific reactions causing false positives. Furthermore, we conducted serum inhibition assays to explore the cross-reactivity between pollen and nut allergens.

RESULTS

The majority of PFAS patients were from northern China, where sensitization to weed pollen, particularly mugwort, was more prevalent than to tree pollen or grass pollens. Hazelnut and walnut were identified as the most frequently sensitizing nut allergens, whereas sensitization rates to other nuts were markedly lower. CRD combined with serum inhibition assays demonstrated a common cross-sensitization between pollen and nut allergens. Notably, the hazelnut component Cor a 1-sIgE was significantly inhibited by birch pollen and its component Bet v 1, while Cor a 8-sIgE showed effective inhibition by mugwort pollen and its component Art v 3.

CONCLUSIONS

This is the first study to comprehensively evaluate nut sensitization and its key allergenic components in Chinese PFAS patients, confirming substantial cross-sensitization with pollen allergens. Specifically, birch and mugwort pollen significantly inhibited IgE binding to hazelnut. These findings provide component-resolved insights into the prevalence and mechanisms of nut allergies in China, enhancing our understanding of the allergenic landscape and informing clinical diagnosis and management strategies.