Lupin sensitisation in a population of 1,160 subjects

Relevance of sensitization to legumes in peanut-allergic children

BACKGROUND

Legume consumption has increased during the two past decades. In France, legumes are responsible for 14.6% of food-related anaphylaxis in children, with peanut as the main allergen (77.5%). Few studies have demonstrated cross-reactivities between peanut and other legumes. The aim of this study was to determine prevalence and relevance of sensitization to legumes in peanut-allergic children.

METHODS

All children, aged of 1-17 years, admitted to the Pediatric Allergy Department of the University Hospital of Nancy between January 1, 2017 and February 29, 2020 with a confirmed peanut allergy (PA) and a documented consumption or sensitization to at least one other legume were included. Data were retrospectively collected regarding history of consumption, skin prick tests, specific immunoglobulin E (IgE), prior allergic reactions, and oral food challenges for each legume.

RESULTS

Among the 195 included children with PA, 122 were sensitized to at least one other legume (63.9%). Main sensitizations were for fenugreek (N = 61, 66.3%), lentil (N = 38, 42.2%), soy (N = 61, 39.9%), and lupine (N = 63, 34.2%). Among the 122 sensitized children, allergy to at least one legume was confirmed for 34 children (27.9%), including six children who had multiple legume allergies (4.9%). Lentil, lupine, and pea were the main responsible allergens. Half of allergic reactions to legumes other than peanut were severe.

CONCLUSION

The high prevalence of legume sensitization and the frequent severe reactions reported in children with PA highlight that tolerated legume consumption should be explored for each legume in the case of PA, and sensitization should be investigated if not.

Recent advances in the management of nut allergy

Peanut/tree nut allergy is common and has been associated with particularly severe reactions. Epidemiological data have shown that the prevalence ranges between 0.05% and 4.9% for tree nut and between 0.5% and 3% for peanut. These large variations can be explained by differences in the age of included patients and the geographical region. In addition, the food consumption modality (ie, raw versus roasted) plays a major role, as heat treatment has the capacity to modify the allergenicity of nuts and legumes. Nut allergies tend to persist into adulthood and consequently have a high impact on quality of life.

Recently, it has been demonstrated that a significant proportion of nut allergic patients are able to tolerate other nuts. As opposed to the avoidance of all nuts, this approach is currently proposed in several tertiary allergy centers. However, diagnosis of nut allergy is particularly difficult due to co-sensitization leading to high rate of false positive skin prick tests and/or specific IgE to whole allergen extracts. The use of component resolved diagnosis leads to major improvement of diagnosis, particularly to distinguish between primary and secondary nut allergies. The basophil activation test has been suggested to be useful but is still used mainly as a research tool. Thus, diagnosis remains mainly based on the oral food challenge, which is considered as the gold standard.

Regarding treatment, avoidance remains the cornerstone of management of nut allergy. Oral immunotherapy is increasingly proposed as an alternative management strategy.

Clinical Relevance of Cross-Reactivity in Food Allergy

The diagnosis and management of food allergy is complicated by an abundance of homologous, cross-reactive proteins in edible foods and aeroallergens. This results in patients having allergic sensitization (positive tests) to many biologically related foods. However, many are sensitized to foods without exhibiting clinical reactivity. Although molecular diagnostics have improved our ability to identify clinically relevant cross-reactivity, the optimal approach to patients requires an understanding of the epidemiology of clinically relevant cross-reactivity, as well as the food-specific (degree of homology, protein stability, abundance) and patient-specific factors (immune response, augmentation factors) that determine clinical relevance. Examples of food families with high rates of cross-reactivity include mammalian milks, eggs, fish, and shellfish. Low rates are noted for grains (wheat, barley, rye), and rates of cross-reactivity are variable for most other foods. This review discusses clinically relevant cross-reactivity related to the aforementioned food groups as well as seeds, legumes (including peanut, soy, chickpea, lentil, and others), tree nuts, meats, fruits and vegetables (including the lipid transfer protein syndrome), and latex. The complicating factor of addressing co-allergy, for example, the risks of allergy to both peanut and tree nuts among atopic patients, is also discussed. Considerations for an approach to individual patient care are highlighted.

Adult and Pediatric Food Allergy to Chickpea, Pea, Lentil, and Lupine: A Scoping Review

BACKGROUND

Nonpriority legume allergies, which include chickpea, pea, lentil, and lupine, are frequently implicated in severe allergic reactions. Yet, studies on public health knowledge and educational needs are near-absent.

OBJECTIVE

To summarize what is known from the existing literature about nonpriority legume food allergy.

METHODS

Eligible, original research articles reported on both nonpriority legume food allergy and 1 or more of prevalence, burden, food labeling information, or current education strategies. Screening was performed by 2 independent reviewers. Conflicts were discussed and if consensus could not be reached, a third reviewer was consulted.

RESULTS

Of the 8976 titles identified, 47 were included subsequent to full-text screening. Most studies identified focused on prevalence, and were conducted in Europe, with additional studies from Asia, and North America. Although we defined burden quite broadly, few studies addressed the burden of nonpriority legume food allergens. Moreover, no studies addressed labeling or educational needs for these allergens.

CONCLUSIONS

Our review of the literature found current research focused on the prevalence of nonpriority legume allergy with significant gaps regarding burden, allergen labeling, and education strategies. To this end, further research on these aspects of nonpriority legume allergy is warranted.

Lupine allergens: Clinical relevance, molecular characterization, cross-reactivity, and detection strategies

Lupine is commonly utilized as a technological food and ingredient in a great variety of processed products (snacks, bakery, meat, and dairy products) principally owing to its nutritional value and technological properties. However, its ingestion, even at trace amounts (in the range of mg protein per kg of food), can lead to severe adverse reactions in allergic individuals. Lupine belongs to the Leguminosae family, having the conglutins (α-, β-, δ-, and γ-) as allergens, among other proteins. Cross-sensitization of lupine-sensitized individuals with other legume species, mainly peanut, can occur, but the associated clinical reactivity is still unclear. The protection of the sensitized individuals should depend on an avoidance diet, which should rely on the compliance of food labeling and, as such, on their verification by analytical methods. Food processing, such as heat treatments, has an important influence on the structural properties of lupine proteins, altering their detectability and allergenicity. In this review, different aspects related with lupine allergy are described, namely, the overall prevalence, clinical relevance, diagnosis, and treatment. The characterization of lupine allergens and their potential cross-reactivity with other legumes are critically discussed. The effects of food matrix, processing, and digestibility on lupine proteins, as well as the available analytical tools for detecting lupine at trace levels in foods, are also herein emphasized.

Food-Induced Anaphylaxis: Role of Hidden Allergens and Cofactors

Food anaphylaxis is on the increase, with those who have an allergy to peanuts, tree nuts, milk, and seafood at the highest risk of developing such a reaction. However, the diet in many societies is increasingly varied, much of the food consumed is prepared outside the home, and meals are often composed of many different ingredients. Anaphylaxis may occur to a composite food, and it may be unclear whether the reaction is due to contamination or to a culprit allergen present in an added ingredient. Composite foods can contain many allergic proteins present in small amounts, which do not always have to be labeled, unless they feature in European or US labeling regulations. These "hidden" allergens include mustard, celery, spices, lupine, pea, natural food colourings, and preservatives, but can occasionally include allergenic material from contaminants such as cereal mites. Hidden allergens can provoke severe reactions to seemingly unconnected foods which might then lead to a diagnosis of idiopathic anaphylaxis. The same problem can arise with two well-known types of food allergy; wheat-dependant exercise induced anaphylaxis and allergy to non-specific Lipid Transfer Protein allergens, both of which might only manifest when linked to a cofactor such as exercise. Many of these risk factors for food anaphylaxis have a common link; the public's engagement with popular concepts of health and fitness. This includes the development of a food and exercise culture involving the promotion and marketing of foods for their health-giving properties i.e., meat substitutes, wheat substitutes, supplements and alternative, or "natural" remedies for common ailments. Some of these foods have been reported as the cause of severe allergic reactions, but because they are often viewed as benign unlikely causes of severe allergic reactions, could be considered to be hidden allergens. The best resource to elicit the likelihood of a hidden allergen provoking an allergic reaction is to take a detailed history of the allergic reaction, presence of co-factors, foods suspected, type of food and where it was consumed. A good knowledge of commonly used ingredients, and list of potential hidden allergen suspects are essential tools for the food allergy detective.

Legumes steam allergy in childhood: Update of the reported cases

In the past few decades, the prevalence of allergic diseases has deeply increased, with a key role played by food allergies. Legumes seem to play a major role towards the overall increase in the scenario of food allergy, since they are an appreciated source, consumed worldwide, due to their high protein content, variable amounts of lipids and for the presence of vitamins. In literature there are numerous descriptions of adverse reactions after ingestion of uncooked and cooked legumes. Nevertheless, cases of allergic reactions induced by inhaling vapours from cooking legumes have rarely been described. Herein the authors report an update of the literature data on allergic reactions caused by legume steam inhalation, underlying the possible pathogenic mechanism of these atopic events and the knowledge of literature data in paediatric age. The importance of this review is the focus on the clinical aspects concerning legume vapour allergy, referring to literature data in childhood.

Skin prick test reactivity to lupin in comparison to peanut, pea, and soybean in atopic and non-atopic German subjects: A preliminary cross-sectional study

The increasing use of lupin in food processing poses a problem of potential (cross-)allergic reactions. To evaluate the prevalence of sensitization to lupin in comparison to that of other legumes skin prick tests were performed with lupin, pea, peanut, and soybean in atopic (n = 81) and non-atopic (n = 102) German adults. Of these 183 subjects, 20 subjects had to be excluded due to invalid skin prick tests (reaction to histamine <3 mm or to sodium chloride >2 mm). Thus, skin prick tests of 163 subjects were included in final analyses. Of 163 subjects, 18 had a positive reaction to at least one legume tested. Overall skin prick test reactivity was different among non-atopic and atopic subjects (P = 0.005). Altogether, six subjects (4%) were sensitized to lupin, 12 (7%) to pea, 5 (3%) to peanut, and 8 (5%) to soybean. Two (2%) of the 92 non-atopic subjects and 4 (6%) of the 71 atopic subjects had a positive skin prick test to lupin. Of the 6 subjects sensitized to lupin, 3 (50%) were also sensitized to pea, 3 (50%) to peanut, and 5 (83%) to soybean. In conclusion, the prevalence rates of lupin sensitization were comparable to or even lower than those of pea, peanut, and soybean. To date, lupin allergy is suspected to be relatively uncommon in the overall German population since lupin sensitization occurred in only 2% of non-atopic subjects. However, there is a clear risk of a lupin allergy in predisposed subjects, since the frequency of lupin sensitization was 6% in atopic subjects. In particular, subjects with existing sensitization or allergy to other legumes are at higher risk for a sensitization or allergy to lupin due to cross-reactivity.

An update on epidemiology of anaphylaxis in children and adults

PURPOSE OF REVIEW

The purpose of the present review is to describe the epidemiology of food-induced, medication-induced, drug-induced, and insect sting-induced anaphylaxis; to summarize recent changes in the incidence of anaphylaxis internationally; and to discuss recent insights into potential risk factors for anaphylaxis.

RECENT FINDINGS

Recent studies confirm that the incidence of anaphylaxis, particularly food-induced anaphylaxis, is increasing world-wide. The rise in anaphylaxis incidence appears most pronounced in children under the age of 5 years, which is also the age group most at risk of hospitalization for food-induced anaphylaxis. Identification of factors that may increase the risk of episodes of anaphylaxis remains an important research priority. Recently, two large cohort studies using data from electronic medical records confirmed that individuals with asthma are at higher risk of anaphylaxis and those with severe asthma have the highest risk of all. With respect to modifiable lifestyle factors, several studies have demonstrated a link between latitude and anaphylaxis, with areas with less year-round sunlight reporting a higher prevalence of food-induced anaphylaxis.

SUMMARY

Reports of an increasing incidence of anaphylaxis internationally highlight the need for identification of modifiable risk factors for anaphylaxis. Emerging evidence suggests that low vitamin D levels may be associated with risk of anaphylaxis and food allergy; however, further studies are required to confirm this.

Lupin allergy: a hidden killer at home, a menace at work; occupational disease due to lupin allergy

The products of the flowering plant, lupin, are increasingly used as a human food product, particularly in baking. Occupational sensitization to lupin with occupational rhinitis, conjunctivitis and asthma was first described in 2001, and confirmed in a larger cross-sectional study in a food processing company in 2006. Sensitization by inhalation may result in occupational asthma, work-exacerbated asthma, occupational rhinitis and conjunctivitis. The incidence of occupational sensitization may be as high as 29%. The relationship with exposure intensity is as yet unclear, and requires further clarification. Although there is little information from long-term studies, these diseases are likely to improve after cessation of exposure. Cross-sensitization to other legumes, particularly peanuts, has been shown by skin prick testing, with potential for serious anaphylactic reactions. This review summarizes the available literature on occupational sensitization to lupin products. It is one of two reviews, one covering the problem of lupin allergy in the home, while the present article deals with lupin sensitization in the workplace. Increased awareness is needed of this occupational hazard to avoid future cases of occupational disease and their accompanying morbidity and potential mortality.

Lupine, a source of new as well as hidden food allergens

The present review summarizes current knowledge about lupine allergy, potential sensitization routes, cross-reactions between lupine and other legumes, and the respective IgE-binding proteins. Since the 1990 s, lupine flour is used as a substitute for or additive to other flours, mostly wheat flour, in several countries of the EU. In 1994, the first case of an immediate-type allergy after ingestion of lupine flour-containing pasta was reported. Since then, the number of published incidents following ingestion or inhalation of lupine flour is rising. So far, the Lupinus angustifolius beta-conglutin has been designated as the allergen Lup an 1 by the International Union of Immunological Societies Allergen Nomenclature Subcommittee. Initially, publications focussed on the fact that peanut-allergic patients were at risk to develop anaphylaxis to lupine due to cross-reactivity between peanut and lupine. At present, however, the ratio between cases of pre-existing legume allergy (mostly peanut allergy) to de novo sensitization to lupine seed is nearly 1:1. Although in December 2006, lupine and products thereof were included in the EU foodstuff allergen list according to the Commission Directive 2006/142/EC amending Annex IIIA of Directive 2000/13/EC in order to prevent severe reactions caused by "hidden food allergens", the majority of patients and medical personnel are still not aware of raw lupine seed as potentially dangerous food allergen.

Lupin allergy and lupin sensitization among patients with suspected food allergy

BACKGROUND

Lupin, a legume with good nutritional value, is used in food production today, most often in bakery products. Lupin sensitization is often seen among patients with reactions to legumes, but the number of reports describing lupin anaphylaxis is also increasing.

OBJECTIVE

To investigate the occurrence of lupin sensitization, cross-reactivity, and lupin allergy among patients with suspected food allergy in Finland, where lupin is a labeled ingredient in few products.

METHODS

The occurrence of positive skin prick test (SPT) reactions to lupin seed flour was studied among 1522 patients with suspected food allergy from November 1, 2005, through December 31, 2007. Clinical histories and diagnostic SPT results were analyzed among patients with positive SPT results to lupin. For 1 patient, ImmunoSpot and lupin radioallergosorbent test inhibition methods were used.

RESULTS

Lupin sensitization was shown in 25 of 1522 patients (1.6%), and probable lupin allergy was diagnosed in 7 of 25 patients, in whom the clinical symptoms varied from anaphylaxis and respiratory symptoms to contact urticaria and itchy mouth. Cross-reactions or concurrent reactions to other legumes were seen in 18 of 25 patients.

CONCLUSIONS

Clinically relevant lupin allergy often occurs in patients without atopic background or other food allergies, although lupin sensitization most commonly seems to represent cross-reactivity to other legumes. The occurrence of lupin allergy in a country where lupin has not been traditionally used is surprisingly common, suggesting that short-term use of modest amounts of lupin can cause serious allergic reactions.