Anaphylaxis from mandarin (Citrus reticulata): identification of potential responsible allergens

We report on a patient with anaphylaxis from mandarin. Temporal relationship between consumption of the fruit, the presence of positive specific IgE, the positive skin test and the basophil activation test for mandarin strongly supported the diagnosis of an IgE-mediated allergy from mandarin. The lipid transfer protein allergen from mandarin fruit was isolated and characterized. Specific IgE levels and IgE immunodetection data indicated the patient's sensitization to orange (Cit s 3) and mandarin (Cit r 3) lipid transfer protein allergens, as well as to germin-like (Cit s 1) allergen. These results were fully confirmed by skin prick test and basophil activation test (BAT) for lipid transfer proteins, and a BAT for Cit s 1. This case report has several particularities. First, in Central and Northern Europe, it is not widely appreciated that citrus fruits, particularly mandarin, can elicit anaphylaxis. Second, this case report re-emphasizes sensitization from lipid transfer proteins to predispose for severe allergic reactions. Finally, it provides an opportunity to summarize the applications of flow cytometry-assisted analysis and quantification of in vitro activated basophils in the diagnostic approach of anaphylaxis from food.