NATURAL LATEX, GRASS-POLLEN, AND WEED POLLEN SHARE IGE EPITOPES

Background: Because of the frequent use of natural latex products, IgE -mediated reactions to latex proteins represent an important health th reat in industrialized countries, Although several latex allergens hav e been characterized and IgE cross-reactivities with allergens present in plant-derived food have been described, limited information is ava ilable regarding the presence of common IgE-binding components in late x and plant pollen, Methods: By using serum IgE from 56 individuals wi th latex allergy, the IgE-binding components in ammoniated latex milk and latex glove extracts were characterized by immunoblotting. The pre sence of cross-reactive IgE-binding components in the different latex extracts, extracts from mugwort, ragweed, timothy grass pollen, and re combinant birch pollen allergens (Bet v 1 and Bet v 2 [birch profilin] ) was studied by immunoblot inhibitions and quantitative competition e xperiments. The involvement of carbohydrates in the constitution of cr oss-reactive IgE epitopes was studied by periodate treatment of extrac ts. Results: Although sera from certain individuals with latex allergy showed IgE reactivity with protein bands of different molecular weigh ts in Western-blotted latex milk and glove extracts, both extracts con tained common IgE epitopes. Although preincubation with recombinant Be t vl and Bet v 2 did not significantly inhibit IgE binding to latex pr oteins, weed and, in particular, timothy grass pollen extract strongly inhibited IgE binding to latex allergens, The cross-reactive IgE epit opes were sensitive to periodate treatment, Conclusions: Mugwort, ragw eed, and timothy grass pollen share IgE epitopes with glycoprotein lat ex allergens, The presence of common epitopes might in part explain cl inical symptoms in patients allergic to pollen on contact with latex.