Abstract

Background: Lupin is a protein-rich legume with a growing presence in the food market worldwide. With increased consumption, lupin allergy (LA) reports are also rising. Uncertainties exist on the cross-reactivity between peanut , lupin, the allergenic potential of different lupin species , sensitization patterns among different populations. Objective: To evaluate the molecular basis of LA and to determine lupin allergens from 3 different species that may be involved in peanut allergy (PA) cross-reactivity.Methods: A total of 43 subjects with PA, those with LA, or controls without food allergy were evaluated with skin prick tests (SPTs) and specific IgEs (sIgEs). Lupin-sensitized subjects were offered a lupin oral food challenge (OFC). Immunoblots and enzyme-linked immunosorbent assays were performed on sera from lupin-sensitized subjects.Results: In this study, 44% of the PA subjects were confirmed to have LA by OFC. Anaphylaxis was the most fre-quent manifestation after lupin consumption, with a minimal eliciting dosage of 1 g lupin flour. There was no dif-ference in lupin sIgE or SPT wheal size between lupin-sensitized and confirmed LA subjects or in the severity of symptoms among confirmed LA subjects. Sera from lupin-sensitized subjects uniformly reacted to all 3 different lupin species. Immunoblotting and enzyme-linked immunosorbent assays revealed immunoglobulin E binding to a- and-y-conglutin in all analyzed sera, whereas a- and 0-conglutin recognition was variable.Conclusion: Our findings reveal a high prevalence of LA among PA subjects, emphasizing lupin must be labeled as an allergen in foods. Owing to high variability in lupin-sIgE and lupin-SPT results, LA diagnosis may require OFC. In our population,-y-conglutin is the major allergen of lupin.(c) 2022 American College of Allergy, Asthma , Immunology. Published by Elsevier Inc. All rights reserved.