Background: : An IgE-mediated allergy against a lipid-transfer protein of grapes was the cause of repeated severe anaphylaxis in a patient after consumption of grapes, wine, and raisins.
Objective: : Although the patient was aware of her grape allergy, avoidance proved difficult and accidental anaphylaxis occurred. Furthermore, wine allergy in a wine-growing district means a non-negligible restriction of quality of life.
Methods: : Although there is little data on specific oral tolerance induction (SOTI) in lipid-transfer protein (LTP) allergy, SOTI with increasing doses starting from approximately 20 mg of grapes was done. For follow-up, skin tests, grape-specific IgE and IgG4, basophil activation tests, and immunoblotting were performed.
Results: : Within 3 days the patient reached tolerance to the daily maintenance dose of 20 g of grapes (about 3 grape pieces) without anaphylaxis symptoms. Two months later, a controlled challenge with a total of 66.5 mL of white wine was tolerated. Grape-specific IgE stayed stable at 2.37 kU/L (class 2) and grape-specific IgG4 was first detectable 21 months after SOTI. Prick-to-prick skin tests continued to be positive to grapes, to raisins, and to white and red wine. The basophil activation test still showed strong IgE-mediated activation of basophils after stimulation with grape extract. Immunoblotting still detected IgE binding to a 8-kDa protein.
Conclusions: : We performed SOTI in a patient with severe IgE-mediated allergy against the LTP Vit v 1 of grapes and reduced the risk of anaphylaxis because of accidental intake of any kind of grapes. However, underlying mechanisms of SOTI and maintenance of the established tolerance are still not known.