IgE reactivity to patatin-like latex allergen, Hev b 7, and to patatin of potato tuber, Sol t 1, in adults and children allergic to natural rubber latex

Background: Patients allergic to natural rubber latex (NRL) frequently show positive skin prick tests (SPT) and hypersensitivity reactions to various fruits, such as avocado, banana, and kiwi, as well as to vegetables such as potato. Methods: Hev b 7 was purified from NRL "C-serum" and Sol t 1 from potato ex tract, and they were detected by immunoblotting. IgE antibodies to Hev b 7 and So1 t 1 were measured with ELISA in sera from 35 adults and 35 children allergic to NRL. ELISA inhibition and immunoblotting were used to study al lergen cross-reactivity. The in vivo reactivity of Hev b 7 and So1 t 1 were demonstrated in the SPT. Results: Seventeen (49%) of the 35 NRL-allergic adults had IgE antibodies t o Hev b 7, in contrast to only one of the 35 NRL-allergic children. Fifteen (43%) of the NRL-allergic adults and 29 (83%) of the NRL-allergic children had IgE antibodies to So1 t 1. Ten (29%) of the adult sera showed IgE bind ing to both So1 t 1 and Hev b 7, and crosswise inhibition tests with pooled sera revealed marked cross-reactivity. In the SPT, both natural Hev b 7 an d So1 t 1 were able to produce a wheal and flare reaction. Conclusions: One-half of the NRL-allergic adults, but only one of the NRL-a llergic children, had IgE antibodies to natural Hev b 7. These results sugg est that Hev b 7 is an important NRL allergen for adults, but not for child ren. Elucidation of the clinical importance of the observed cross-reactivit y between Hev b 7 and Sol t 1 requires further studies.