Specific IgE to recombinant allergens (rBetv1 and rBetv2) and apple allergy in patients with pollinosis

ABSTRACTThe presence of IgE antibodies to the allergens rBetvl and rBetv2 was investigated in the sera of 99 patients with specific IgE to apple extract by comparing a group of 43 patients who had oral allergy syndrome (OAS) after ingestion of apple with a group of 56 patients without OAS who had only seasonal respiratory symptoms. The incidence of the presence of IgE antibodies to rBetv1 was 88.1%. All patients had levels of IgE to apple extract greater than 0.35 kU/L. After eating apple, patients allergic to birch pollen with OAS showed significantly higher levels of IgE to apple extract and rBetv1 than patients without OAS (P=0.007 and P=0.0002, respectively). Twenty of 56 patients (35.7%) in the group without OAS who produced specific IgE to apple did not have specific IgE against rBetv1 and rBetv2 and were symptomless after eating apple. In conclusion, patients allergic to birch pollen with specific IgE to rBetv1 showed a significantly elevated frequency of apple allergy. In contrast, our results show that fruit-related symptoms require not only high specific serum IgE levels, but a strong cellular sensitization to birch pollen allergens, together with an increased cellular reactivity to apple allergens