Methods: Fifty eight patients were included in the study. The clinical history, the positive result of the skin prick test with the birch extract and symptoms after consumption plant food were the condition for qualifications. The immunoblotting was performed for the patients with the positive value of birch, apple, celery and/or carrot specific IgE to confirm the cross-reactivity.
Results: Sera of 13 patients ( 18 patients were analyzed) revealed positive results in the immunoblotting method. Sera of only 12 patients revealed the reaction against the birch pollen protein with a molecular weight 17-18 kDa corresponding to the main birch allergen Bet v 1. Sera of only 2 of these patients revealed the presence of antibodies cross-reacting with the apple protein with the same molecular weight, which may indicate the main allergens of these foods – Mal d 1. Serum of 6 patient revealed the presence of antibodies cross-reacting with apple and celery protein with the same molecular weight, which may indicate the main allergens of these foods – Mal d 1 and Api g 1. Serum of only one patient revealed the presence of antibodies cross-reacting with the apple, celery and carrot protein with the same molecular weight, which may correspond the main allergens of these foods – Mal d 1, Api g 1 Dau c 1. Additionally sera of 6 persons demonstrated the presence of antibodies reacting with apple protein with the molecular weight 10kDa which may correspond the lipid transfer protein (LTP). Among some of the patients , antibodies which have not been identified so far ,reacted with birch, apple and celery proteins.
Conclusions: Although the immunoblotting is an effective method confirming the existences of the cross-reactivity, it still remains the method of verifying and supplementing other diagnostic tests, and a negative result doesn't exclude the existence of this kind of allergy.