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Original Article
 

IgE reactivity to profilin in platanus acerifolia pollen-sensitized subjects with plant-derived food allergy
 

E. Enrique, R. Alonso, B. Bartolomé*, M. San Miguel-Moncín, J. Bartra, B. Fernández-Parra, R. Tella, J. A. Asturias*, I. Ibarrola*, A. Martínez*, A. Cisteró-Bahíma.

Allergy Department. Institut Universitari Dexeus. Universitat Autònoma de Barcelona. Barcelona. Spain
*Laboratorios Bial-Arístegui. I+D. Bilbao. Spain

J Invest Allergol Clin Immunol 2004; Vol. 14(4): 335-342
 

 Abstract


Background: The presence of profilin-specific IgE antibodies is a cause of cross-reactivity betweenbotanically-unrelated allergen sources. Recently, the association between Platanus acerifolia pollinosis and plantderived food allergy has been described. The aim of this study was to ascertain whether the P. acerifolia profilin is involved in such cross-reactivity.

Methods: Twenty-three patients suffering from Platanus acerifolia pollinosis and plant-derived food allergy were evaluated in an allergy department. Specific IgE levels to P. acerifolia pollen, P. acerifolia profilin and food extracts were measured. Molecular masses of IgE-binding proteins were calculated by Western blotting and crossreactivity studies among P. acerifolia profilin and different food extracts were evaluated by Enzyme AllergoSorbent Test (EAST)-inhibition assays. Also, EAST-inhibition assays with the two known P. acerifolia allergens, Pla a 1 and Pla a 2, were performed.

Results: Surprisingly, a high IgE-binding prevalence (90%) of P. acerifolia profilin was found. EAST-inhibition showed high inhibition values when Platanus acerifolia pollen extract was used as free phase and plant-derived food extracts as solid phase, whereas the other way round showed low inhibition values. IgE reactivity to profilin was studied using a pool of patient sera, by EAST-inhibition assays with hazelnut, apple peel, peanut, chickpea and peanut extracts as solid phase and no inhibition was obtained when P. acerifolia profilin was used as inhibitor phase. The same results were obtained when purified Pla a 1 and Pla a 2 were also used as inhibitor phase.

Conclusions: The clinical association observed between Platanus acerifolia pollen and plant-derived food could be explained by the in vitro IgE cross-reactivity detected by EAST-inhibition. However, it appears that neither P. acerifolia profilin nor the two major allergens described (Pla a 1 and Pla a 2) can explain such a strong crossreactivity.

Key words: oral allergy syndrome, plant-derived food allergy, Platanus acerifolia pollinosis, Profilin.