A case of allergy to beer showing cross-reactivity between lipid transfer proteins.

BACKGROUND

Lipid transfer proteins (LTPs) are highly conserved proteins present in a broad spectrum of fruits and vegetables that might represent a novel plant panallergen.

OBJECTIVE

To demonstrate that LTP is an important allergen in beer and that beer LTP cross-reacts with LTP from botanically unrelated plant-derived foods.

METHODS

Serum from a patient with clinical allergy to both beer and Rosaceae was studied for IgE reactivity to LTP to several vegetable foods by RAST, ELISA, immunoblot, and inhibition studies.

RESULTS

Patient's serum showed a strong IgE reactivity to LTP purified from peach peel, carrot, and broccoli, and to a 10 kD protein in both apple and peach immunoblots, whereas no reactivity to birch cross-reactive allergens such as Bet v 1, profilin, or carbohydrates was found. In inhibition studies, preabsorption of serum with apple, walnut, hazelnut, peanut, corn, and rice caused a fall of 97%, 20%, 66%, 91%, 94%, and 93%, respectively, of its reactivity to peach LTP. Beer RAST fell from 1.8 IU/mL to <0.1 IU/mL when a patient's serum was preabsorbed with recombinant carrot LTP.

CONCLUSIONS

LTP is a relevant allergen in beer. Beer LTP may cross-react with LTP from several other plant-derived foods.