CROSS-REACTIVITY OF CELERY AND APPLE ALLE RGENS

Cross-reactivity of celery and apple allergens. We studied the cross-r eactivity of celery and apple allergens by PAST immunoblot immunoblot inhibition, and ELISA inhibition. Five patients with celery allergy, 8 patients with apple allergy, and 3 patients with both celery and appl e, and additionally with birch or mugwort pollen allergy revealed posi tive reactions in skin tests and PAST with the corresponding clinicall y relevant pollen or food extract. In 11 patients we observed a sensit ization to certain allergens without clinical substrate. The common oc currence of IgE antibodies to celery and apple was detected in 15 (of the 16) patient sera by PAST The immunoblots with rabbit anti Bet v1 a nd with anti-recombinant birch pollen revealed a Bet-vl-related protei n at 18 kD and the profilin at 15 kD, respectively. The IgE of all cel ery allergic patients was found to bind to the 15 or 18 kD apple aller gens, the IgE of 7 (of the 8) apple allergic patients bound to the 18 kD or to both the 15 and 18 kD celery allergens. In the immunoblot and ELISA inhibition studies, apple revealed a greater inhibition capabil ity for celery than celery for apple. Probably, the 18 kD allergen of celery has less IgE-binding epitopes than the corresponding apple alle rgen. Because of the cross-reactivity of the IgE antibodies with celer y and apple allergens, the common occurrence of allergies against thes e foods should be expected. The high PAST values, the positive skin te sts, and the IgE binding in the blots might hint to an elevated risk f or a manifestation of a celery and apple allergy.