Lupin, a potential “hidden” food anaphylaxis allergen: An alert from the Allergy‐Vigilance Network®
Authors: Guillaume Pouessel, Dominique Sabouraud‐Leclerc, Pascale Beaumont, Amandine Divaret‐Chauveau, Eléna Bradatan, Pascale Dumond, Yasemin Karaca, Jean‐Marie Renaudin, Carine Metz‐Favre, Delphine Delalande, Anne‐Karine Correard, Sélina Tscheiller, Xavier Van der Brempt
Journal: Allergy (2024)

Lupin is a legume considered as an emerging food allergen, but the true prevalence of lupin allergy is not known.1 Due to the increasing consumption of lupin and its potential cross-reactivity with peanut, the Allergy-Vigilance Network® (AVN) aimed to report lupin-induced anaphylaxis cases and compare their main characteristics to other foods (See Data S1 for Material and Methods). Of the 2708 cases of food-induced anaphylaxis documented by AVN (2002-2020), 62 (2.3%) cases were induced by lupin and cases are presented by time periods and according to total number of food-induced anaphylaxis cases (Figure S1). The main characteristics of these 62 cases (mean age: 32.1 years [SD: 21.4], 35% in children <18 years, 66% in females) are presented in Table 1. Nine (15%) patients had a history of lupin allergy confirmed by an allergist and 4 (6%) a known sensitization to lupin; 22 (35%) patients had a known food allergy (peanut, n = 16). Allergic sensitizations according to foods and families of component-resolved reactivity are presented in the Figure S2. Of the 62 patients, a history of asthma was reported in 14 (23%), and allergic rhinitis in 12 (19%). Regarding the description of the anaphylaxis reaction, Grade 2 (according to Ring and Messmer2) reactions were recorded in 36 cases (58%), Grade 3 in 26 cases (42%). A cofactor was identified in 10 (16%) and 7 (11%) anaphylaxis reactions were biphasic. Reactions occurred mainly at home (n = 26, 42%) (See Data S1 for additional results). Foods identified as responsible of the 62 cases of lupin-induced anaphylaxis are presented in the Figure S3. Fifty-nine (95%) cases involved prepacked food products, mainly pastries, biscuits, and breads (n = 47, 76%). In 8 (13%) cases, the diagnosis of lupin-induced anaphylaxis was highly suspected (previous allergic reactions to lupin in 7 cases–missing data in one patient-, anaphylaxis after the consumption of an industrial bakery product in 8 cases, confirmation of lupin sensitization and exclusion of other food allergy after allergy work up in 8 cases), but lupin was undeclared as an ingredient in the consumed prepacked food product. Compared to adults, children (<18 years) with lupin-induced anaphylaxis were more likely to be males (p < 10−3), to have a history of asthma (p = .003), and a peanut allergy (p < 10−3) (Table 1). Compared to other foods, lupin-induced anaphylaxis was more frequent in females (p = .003), in adults (p = .004), in individuals with a peanut allergy (p < 10−3) and after prepacked food products consumption (p < 10−3) (Table 2). Hypotension (p < 10−3), laryngeal oedema (p = 0.048), bronchospasm (p < 10−3), and biphasic reaction (p < 10−3) were more frequent in lupin-induced anaphylaxis compared to other foods (Table 2). Our data shows that lupin is involved in around 2.3% of anaphylaxis cases in France over the two last decades, with a stable frequency at around 1.2%–1.4% over the last decade, whereas it is reported in 0.8% of cases in Europe over the same time period.3 We strongly believe that this data highlights an under recognition and underestimation of lupin allergy in Europe. In our study, a quarter of patients with a lupin-induced anaphylaxis had a history of peanut allergy, and 8% a history of another legume allergy. This suggests a significant degree of cross-reactivity between lupin and other legumes, particularly peanut. In the Netherlands, in 39 peanut-sensitized adults, 82% were sensitized to lupin, of whom 35% reacted during a food challenge.4 In a French survey conducted in 195 children with peanut allergy, 122 (63%) were sensitized to at least one legume, lupin was the most frequent (n = 63, 33%) and 12 were allergic to lupin.5 There is a need to better understand the relevance of cross-reactivity between lupin and legumes, the potential clinical impact of different lupin species at a molecular level as well as the diversity of the allergen composition using proteomics.6, 7 Our data supports that there are specificities of lupin-induced anaphylaxis cases compared to other food allergens. Compared to peanut-induced anaphylaxis reported by the European Anaphylaxis Registry, lupin-induced anaphylaxis seems to occur more frequently in adulthood, in females, with less severity and a higher ingested amount of food allergen.8 One limitation of our study is that our data may not be representative of all European countries. There were also missing data because some questions were not asked from the beginning of the data collection. Lupin is an emerging food allergen over the last two decades that may be present in prepacked food products. Allergists should be aware of lupin cross-reactivity with peanut and other legumes, and lupin should be systematically tested if not regularly consumed in peanut allergic patients. Patients with a history of food anaphylaxis without any obvious trigger should be systematically tested for lupin. Guillaume Pouessel analysed, interpreted the data and wrote the draft. Yasemin Karaca performed the statistical analysis, interpreted the data and reviewed the draft. Dominique Sabouraud-Leclerc, Pascale Beaumont, Amandine Divaret-Chauveau, Pascale Dumond, Xavier Van der Brempt were major contributors in reviewing the draft and improving the paper with critical analysis. Sélina Tscheiller collected data from the Allergy-Vigilance Network®. All authors read and approved the final manuscript. None. We acknowledge all the Allergy-Vigilance Network® members who participated in this study and collected data. GP has provided consultation and speaker services for AI Therapeutics, Bausch+Lomb, Stallergenes, Novartis, DVB technology, ALK-Abello; serves as a medical consultant/advisor for Bausch+Lomb, Theravia and AI Therapeutics. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions. Data S1. Figure S1. Figure S2. Figure S3. 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