Clinically relevant peach allergy is related to peach lipid transfer protein, Pru p 3, in the Spanish population

Background: Sensitization to peach and related Rosaceae fruits without clinical expression is commonly observed as the result of the extensive cross-reactivity of IgE antibodies directed toward lipid transfer proteins (LTPs), Bet v 1 homologues, profilins, and carbohydrate determinants. Objective: We aimed to study whether there are any clinical or immunologic differences between patients allergic to peach and those who have a current clinically irrelevant sensitization to this fruit. Methods: One hundred subjects with adverse reactions to peach were evaluated by medical history, skin prick tests with fresh peach and purified peach UP (Pro p 3), and specific IgE determinations to peach, rBet v 1, and rBet v 2 (birch profilin). Clinical reactivity to peach was established by double-blind, placebo-controlled food challenges. The clinical characteristics and the in vivo and in vitro tests were compared between allergic and nonallergic patients. Results: Peach allergy was confirmed in 76 patients and ruled out in 16; 2 patients dropped out, and the study was not conclusive in 6 individuals (placebo reactors). Pollen allergy was found in 76% of the allergic patients and in 100% of the nonallergic patients. Positive responses to Pro p 3, rBet v 1, and rBet v 2 were observed in 62%, 7%, and 34% of patients allergic to peach, respectively. The sensitization rate to Pru p 3 was significantly higher among subjects allergic than nonallergic to peach (62% vs 31%, P = .02). IgE responses to rBet v 2 were more frequent among subjects allergic to pollen, but no difference was observed in the presence or absence of peach allergy. Conclusions: Pro p 3 is the major allergen of peach in our population, and the IgE response to this allergen is related to the clinical expression of peach allergy. Sensitization to profilin is observed in those patients with an associated pollen allergy but does not appear to be related to the clinical reactivity to peach.