Component-resolved diagnosis of plant food allergy by SPT.

BACKGROUND Fruits and vegetables may contain both labile and stable allergens. The former induce only OAS, whereas stable allergens may induce systemic reactions. Component-resolved diagnosis (CRD) of allergy to plant foods is therefore essential for the clinical management of allergic patients. METHODS 80 adults allergic to plant foods underwent SPT with purified natural date palm profilin (Pho d 2), purified Mal d 1, a peach extract containing uniquely LTP, and with a kiwi extract containing uniquely stable allergens. RESULTS 58 (72%) patients were monosensitized: 24 to Mal d 1, 24 to profilin, 7 to LTP, and 3 to kiwi. 22 patients were multi-sensitised: 14 to Mal d 1 and profilin, 2 to Mal d 1 and kiwi, 1 to LTP and profilin, 3 to LTP and Mal d 1, and 2 to LTP, Mal d 1 and profilin. Mal d 1 and LTP sensitisation were associated with apple and peach allergy, respectively, whereas profilin sensitisation was associated with allergy to melon, watermelon, banana, tomato and citrus fruits. 18/21 kiwi-allergic patients were sensitised to one of the cross-reacting allergens, but 2/18 reacted to kiwi-specific allergens as well. CONCLUSIONS In patients with allergy to plant-derived foods CRD can be performed by SPT with purified allergen proteins. In the future, the availability of a larger number of purified natural or recombinant allergens for SPT will represent a simple means to classify food-allergic patients properly on the first visit.