Background: Epidemiological data on the prevalence and risk factors of latex sensitization have suggested a significant association between latex sensitization and the presence of one or more positive skin prick test responses to aeroallergens, food allergens and to one or more insect venoms. Xylose and core 3-fucose are typical complex glycans in plants and are foreign to mammals. Plant N-glycans and insect N-glycans may cross-react in humans.
Objective: The aim of our study was to investigate whether there are cross-reactive IgE-binding structures in natural rubber latex (NRL) and hymenoptera venoms and to examine their nature.
Methods: Hundred and twenty-five consecutive patients with insect venom allergy were screened for coincidental latex-specific IgE. IgE-binding components in the venoms from Apis mellifera and/or vespula species and in NRL extracts were characterized by IgE-immunoblotting to the natural allergen sources and determination of specific IgE to recombinant allergens. Cross-reactive components were investigated by inhibition experiments. The involvement of carbohydrates in the constitution of cross-reactive IgE-epitopes was further examined by specific IgE-binding to cross-reactive carbohydrate determinants (CCD) in bromelain and horseradish peroxidase as well as by periodate treatment.
Results: NRL glove extracts inhibited patients' serum IgE-binding to venom allergens. Vice versa, the IgE-binding to latex glove extracts could be inhibited by pre-incubation with the insect venoms. Specific IgE-binding to recombinant latex allergens was absent, whereas the cross-reactive IgE-epitopes were sensitive to periodate treatment and specific IgE to CCD (MMXF and MUXF type) could be detected.
Conclusion: Insect venoms and NRL share IgE-binding CCD that may be responsible for positive serological test results to NRL in patients with insect venom allergy. This copositivity occurs frequently (13.6%) among venom-allergic individuals and did not elicit clinical symptoms upon contact to latex in the patients examined. In contrast, true cosensitization to insect venoms and NRL allergens can occur and may not be missed.