Hydrolysed egg displays strong decrease in allergenicity and is well tolerated by egg-allergic patients.

Food allergies are believed to be on the rise, and currently, management relies on the avoidance of the food. Hen's egg allergy is after cow's milk allergy the most common food allergy; eggs are used in many food products and thus difficult to avoid. A technological process using a combination of enzymatic hydrolysis and heat treatment was designed to produce modified hen's egg with reduced allergenic potential. Biochemical (SDS-PAGE, Size exclusion chromatography and LC-MS/MS) and immunological (ELISA, immunoblot, RBL-assays, animal model) analysis showed a clear decrease in intact proteins as well as a strong decrease of allergenicity. In a clinical study, 22 of the 24 patients with a confirmed egg allergy who underwent a double-blind food challenge with the hydrolysed egg remained completely free of symptoms. Hydrolysed egg products may be beneficial as low-allergenic foods for egg-allergic patients to extent their diet.

Clinical presentation and diagnosis of meat allergy in Switzerland and Southern Germany.

STUDY/PRINCIPLES: The aim of this study was to investigate the clinical characteristics of meat allergy, to validate the routine diagnostic tools and to compare our results with data from the literature. METHODS: We recruited within the framework of the EU-project REDALL adult patients and children with a positive case history of meat allergy. Definitive inclusion criteria were either a history of an anaphylactic reaction to meat or a positive titrated double-blind placebo-controlled food challenge with the incriminated meat. Sensitisation to meat was assessed in all patients by skinprick-testing with meat extracts and in vitro determination of specific IgE to pork, beef and chicken (CAP-FEIA). RESULTS: Between 3/2003 to 6/2005 we identified thirteen patients with a positive case history of a meat allergy to either chicken (n = 6), beef (n = 5) or pork (n = 2), respectively. Meat allergy associated symptoms as reported by the patients ranged from contact urticaria of the oral mucosa (oral allergy syndrome, OAS) to anaphylactic reactions. Skin testing with the responsible meat was positive in nine patients, and in vitro determination of specific IgE in four patients. Under DBPCFC one patient responded with nausea and dysphagia after 10.2 g of chicken and two patients either with urticaria or nausea, diarrhoea, emesis and abdominal pain at 0.102 g and 34 g of beef, respectively. CONCLUSION: Meat allergy seems to be an uncommon food allergy in Central Europe. Meat induced symptoms range from OAS to severe anaphylactic reactions. The routine-diagnostic tools, i.e., skin testing and in vitro determination of specific IgE had a low sensitivity among our patients.

Strategy for allergenicity assessment of 'natural novel foods': clinical and molecular investigation of exotic vegetables (water spinach, hyacinth bean and Ethiopian eggplant).

BACKGROUND: Foods not commonly consumed in the European Union must be proven safe before being brought to market, including an assessment of allergenicity. We present a three-stepwise strategy for allergenicity assessment of natural novel foods using three novel vegetables, namely, water spinach, hyacinth bean, Ethiopian eggplant. METHODS: First, vegetable extracts were analyzed for the presence of pan-allergens [Bet v 1 homologous proteins, profilins, nonspecific lipid transfer proteins (LTP)] by immunoblot analysis with specific animal antibodies. Secondly, the IgE-binding of the food extracts was investigated by EAST (Enzyme-allergosorbent test) and immunoblot analysis using sera with IgE-reactivity to known pan-allergens or to phylogenetically related foods from subjects (i) allergic to birch, grass and mugwort pollen, (ii) with food allergy to soy, peanut, tomato, multiple pollen-related foods and (iii) sensitized to LTP. Thirdly, the clinical relevance of IgE-binding was assessed in vivo by skin prick testing (SPT) and open oral food challenges (OFC). RESULTS: Profilin and LTP were detected by animal antibodies in all vegetables, a Bet v 1 homologue selectively in hyacinth bean. IgE-binding to LTP, profilin and a Bet v 1 homologue was proven by immunoblot analysis and EAST. Positive SPT and OFC results were observed for all vegetables in pollen-allergic patients. CONCLUSIONS: Our stepwise procedure confirmed the presence and IgE-binding capacity of novel vegetable proteins homologous to known allergens in endemic vegetable foods. In vivo testing proved the potential of the novel vegetables to elicit clinical allergy. Hence, our described algorithm seems to be applicable for allergenicity testing of natural novel foods.