Fruit-pollen-latex cross-reactivity: implication of profilin (Bet v 2)

Background: An association between allergy to fruits and latex, and between pollen and plant-derived food has been described. The cross-reactive struc tures responsible for these associations have not yet been completely eluci dated. Methods: IgE reactivity to the recombinant allergens Bet v 1 and Bet V 2, d ifferent pollens, natural latex, papain, and bromelain was investigated in 29 patients with allergy to fruits or vegetables who lived in an area witho ut birch trees. Results: Exactly 79.3% of patients were allergic to grass pollen, and two o f them had clinical allergy to latex. Serum IgE reactivity (CAP) to birch p ollen was found in 65% of patients, to Bet v 2 in 51.7%, to Bet v 1 in 3.4% , to latex in 58.6%, to bromelain in 51.7%, and to papain in 17.2% of patie nts. All subjects with positive IgE to Bet v 2 had also reactivity to latex , grass, olive tree, birch, and mugwort pollens. The six patients not aller gic to pollen did not show IgE reactivity to latex, Bet v 1, or Bet v 2. A significant correlation was found between CAP to rater with Bet v 2 (r=0.86 , P<0.001), with birch (r=0.86, P<0.001), and with ryegrass (r=0.81, P<0.00 1). Immunoblotting using nine sera with positive CAP to birch pollen showed IgE-binding to a 15-kDa band that was recognized by antiprofilin monoclona l antibody. Bet v 2 CAP could be inhibited up to 52% by ryegrass and up to 23% by mugwort. CAP to latex was almost completely inhibited by ryegrass po llen with sera from five subjects without symptoms due to latex, whereas no inhibition was observed with serum from one patient with allergy to latex. Conclusions: Patients with allergy to plant-derived food and associated pol linosis showed a high frequency of IgE reactivity to Bet v 2, which may cau se positive serum IgE determinations to latex and birch pollen due to the p resence of cross-reactive epitopes. IgE reactivity to Bet v 2 may serve as an indicator of broad sensitization.