RESUMEN
BACKGROUND: Lupine is used increasingly in food products. The development of lupine allergy in peanut-allergic patients is believed to occur as a result of cross-reactivity between lupine and peanut proteins. OBJECTIVE: To investigate the degree of immunoglobulin (Ig) E cross-reactivity between allergens in lupine and peanut. METHODS: We investigated IgE cross-reactivity between lupine alpha-, beta-, gamma-, and delta-conglutins and the major peanut allergens Ara h 1, Ara h 2 and Ara h 3 using enzyme-linked immunosorbent assay with sera from patients with coexisting peanut and lupine allergy. RESULTS: Peanut proteins inhibited IgE binding towards alpha- conglutins, delta-conglutins, and, to a lesser degree, beta-conglutins, while no IgE cross-reaction with delta-conglutin was observed. Ara h 2 most potently inhibited IgE binding to lupine and delta-conglutins, while Ara h 1 most potently cross-reacted with beta-conglutin. Ara h 3 was apparently not involved in these mechanisms. CONCLUSIONS: The present study reveals IgE cross-reactivity between the 2S albumins Ara h 2 and delta-conglutin, and the 7S vicilin-like Ara h 1 and beta-conglutin, which are possibly based on homologies between phylogenetically related proteins. Ara h 2 was the most potent inhibitor of IgE binding to lupine conglutins.
Asunto(s)
Arachis/inmunología , Hipersensibilidad a los Alimentos/inmunología , Inmunoglobulina E/inmunología , Lupinus/inmunología , Albuminas 2S de Plantas/inmunología , Adolescente , Alérgenos/inmunología , Antígenos de Plantas/inmunología , Unión Competitiva , Niño , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Epítopos , Femenino , Hipersensibilidad a los Alimentos/sangre , Glicoproteínas/inmunología , Humanos , Inmunoglobulina E/sangre , Masculino , Proteínas de la Membrana , Hipersensibilidad al Cacahuete/sangre , Hipersensibilidad al Cacahuete/inmunología , Proteínas de Plantas/inmunología , Proteínas de Almacenamiento de Semillas/inmunología , Homología de Secuencia de AminoácidoRESUMEN
Allergy to hazelnut is one of the most prevalent causes of severe food-allergic reactions in Norway, as recorded by The Norwegian National Reporting System and Register of Severe Allergic Reactions to Food. In the majority of the reported cases, there is "hidden", unlabelled hazelnut protein in processed foods like chocolate, cookies and cereal mixtures the eliciting agent. For a food survey study performed to evaluate the labelling practices with regards to hazelnut on behalf of the Norwegian Food Safety Authority, a new sensitive time-resolved fluoroimmunoassay (TR-FIA) for the detection of hazelnut protein traces in food matrices was developed and validated. The unique fluorometric properties of the europium-chelates used improved the signal-to-noise ratio because of low matrix interference and led to an enhanced sensitivity. The limit of detection was 0.1 mg/kg and the limit of quantitation was 0.33 mg/kg hazelnut protein. The recovery ranged from 73% to 123% in cookies and cereals, and from 50 to 77% in chocolate. The intra-assay precision was 7% and the inter-assay precision was 19%. Of 100 randomly chosen retail food products in Norway labelled "may contain hazelnut", 36 contained <0.2 mg/kg and seven >10 mg/kg hazelnut protein, demonstrating how differently this precautionary label is used.
Asunto(s)
Corylus/química , Fluoroinmunoensayo/métodos , Análisis de los Alimentos/métodos , Contaminación de Alimentos/análisis , Hipersensibilidad a la Nuez , Proteínas de Plantas/química , Corylus/efectos adversos , Fluoroinmunoensayo/normas , Immunoblotting , Elementos de la Serie de los Lantanoides/química , Proteínas de Plantas/aislamiento & purificación , Sensibilidad y EspecificidadRESUMEN
Cobalt and copper concentrations were measured in 599 lamb livers collected at slaughter from 58 sheep flocks in 6 different parts of Norway in 1993. Information about pasture, additional feeding and mineral supplements in the flocks was obtained through a questionnaire. Average hepatic levels of cobalt in the lamb flocks varied from < 0.003 to 0.22 microg/g ww, and of copper from 5 to 240 microg/g ww. Flocks with deficient or marginal cobalt status were found in all parts of southern Norway, but primarily in the west and south-west. Some flocks with marginal copper status were found in the south-west, while flocks with signs of excessive hepatic copper concentrations were found mainly in inner parts of central and northern Norway. Hepatic copper concentrations were significantly higher in lambs that had grazed mountain pastures than in those that had grazed lowland pastures in the summer.