Background Peanut is one of the most common foods responsible for food-induced anaphylaxis in adults. Unfortunately, commonly used allergen-specific immunotherapy has not been successful for the treatment of food allergy because of the high risk of serious side-effects. Therefore, chemically modified allergen extracts with improved safety characteristics are being investigated for its potential use in immunotherapy. Methods Peanut extract (PE) from de-fatted peanut powder was modified by reduction of disulfide bonds and subsequent alkylation of the free Cys residues resulting in an allergoid PE (mPE). The potency of PE and mPE to induce PE-specific IgG was evaluated after i.p. injections in mice. Subsequently, mice were sensitized intra-gastrically for PE and either 1) subcutaneously challenged with different concentrations of PE or mPE to assess the safety profile of these product candidates, or 2) de-sensitized with subcutaneous injections of either PE or mPE (immunotherapy) for 4-6 weeks, followed by oral and i.p. challenges to assess the efficacy profile of the preparations. To assess the safety and efficacy profile of mPE compared to PE, body temperature was measured after challenge as an objective parameter of an anaphylactic shock response. In addition, during the course immunotherapy, blood samples were taken for analysis of antibody responses and mast cell activation.
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