Clinical relevance of sensitization to lupine in peanut-sensitized adults

Background: The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanutsensitized patients. Furthermore, to determine the eliciting dose (ED) for lupine using double-blind placebo-controlled food challenges (DBPCFC). Methods: Thirty-nine unselected peanut-sensitized patients were evaluated by skin prick tests (SPT) and ImmunoCAP to lupine, pea, and soy. Clinical reactivity was measured by DBPCFC for lupine, and by history for pea and soy. Results: Eighty-two percent of the study population was sensitized to lupine, 55% to pea, and 87% to soy. Clinically relevant sensitization to lupine, pea, or soy occurred in 35%, 29%, and 33% respectively of the study population. None of the patients was aware of the use of lupine in food. The lowest ED for lupine, inducing mild subjective symptoms, was 0.5 mg, and the no observed adverse effect level (NOAEL) was 0.1 mg. No predictive factors for lupine allergy were found. Conclusion: In peanut-sensitized patients, clinically relevant sensitization to either lupine or to pea or soy occurs frequently. The ED for lupine is low (0.5 mg), which is only five fold higher than for peanut. Patients are not aware of lupine allergy and the presence of lupine in food, indicating that education is important to build awareness

Lupine Allergy: Not Simply Cross-Reactivity with Peanut or Soy

Background: Reports of lupine allergy are increasing as its use in food products increases. Lupine allergy might be the consequence of cross-reactivity after sensitization to peanut or other legumes or de novo sensitization. Lupine allergens have not been completely characterized. Objectives: We sought to identify allergens associated with lupine allergy, evaluate potential cross-reactivity with peanut, and determine eliciting doses (EDs) for lupine allergy by using double-blind, placebo-controlled food challenges. Methods: Six patients with a history of allergic reactions to lupine flour were evaluated by using skin prick tests, CAP tests, and double-blind, placebo-controlled food challenges. Three of these patients were also allergic to peanut. Lupine allergens were characterized by means of IgE immunoblotting and peptide sequencing. Results: In all 6 patients the ED for lupine flour was 3 mg or less for subjective symptoms and 300 mg or more for objective symptoms. The low ED and moderate-to-severe historical symptoms indicate significant allergenicity of lupine flour. Two patients allergic to lupine but not to peanut displayed IgE binding predominantly to approximately 66-kd proteins and weak binding to 14- and 24-kd proteins, whereas patients with peanut allergy and lupine allergy showed weak binding to lupine proteins of about 14 to 21 or 66 kd. Inhibition of binding was primarily species specific. Conclusion: Lupine allergy can occur either separately or together with peanut allergy, as demonstrated by 3 patients who are cosensitized to peanut and lupine. Clinical implications: Lupine flour is allergenic and potentially cross-reactive with peanut allergen, thus posing some risk if used as a replacement for soy flour

Assessment of protein allergenicity on the basis of immune reactivity: animal models.

Because of the public concern surrounding the issue of the safety of genetically modified organisms, it is critical to have appropriate methodologies to aid investigators in identifying potential hazards associated with consumption of foods produced with these materials. A recent panel of experts convened by the Food and Agriculture Organization and World Health Organization suggested there is scientific evidence that using data from animal studies will contribute important information regarding the allergenicity of foods derived from biotechnology. This view has given further impetus to the development of suitable animal models for allergenicity assessment. This article is a review of what has been achieved and what still has to be accomplished regarding several different animal models. Progress made in the design and evaluation of models in the rat, the mouse, the dog and in swine is reviewed and discussed

Detoxification of the estertin stabilizer bis-([beta]-carbobutoxyethyl)tin dichloride in rats by hydrolysis of the ester bond

In a previous comparative toxicity study with alkyltin and estertin stabilizers, it was recognized that estertim compounds displayed in vitro lymphocytotoxic effects comparable to the dialkyltin compounds, but did not induce lymphoid atrophy when administered in vivo to rats as was found for the dialkyltin compounds. The discrepancy between the in vitro and in vivo toxicity of estertin compounds prompted us to study the metabolism of the estertin compound bis-(β-carbobutoxyethl)tin dichloride (CBETC) in rats. The hydrolysis product bis-(β-carboxyethl)tin dichloride (CETC) was the only metabolite detectable using TLC. After daily intravenous administration of 20 mg CBETC/kg body weight CETC was detected in urine only, whereas no faecal excretion of organotin was found. Intravenous adminstration of relatively large amounts of 20 mg CETC/kg body weight indicated that this compound is not metabolized by rapidly excreted in urine, probably because of its hydrophilic nature. Daily gavage of 15 mg CBETC/kg body weight resulted in the excretion of apprecable amounts of CETC in urine, but CETC was also found in faeces together with the parent compound. In the gastrointestinal tract CETC would be formed locally probably by acid hydrolysis of CBETC as was shown also in vitro in acidified water. Esterases in the gastrointestinal tract, tissues and blood might also be responsible for the fast hydrolysis of CBETC. As shown in our previous study the hydrolysis product CETC did not cause any lymphocytotoxic effect. Therefore we conclude that in the rat the estertin compund CBETC is effectively detoxified by hydrolysis of the ester bond