Sensitization to Hymenoptera venom marker allergens: Prevalence, predisposing factors, and clinical implications

BACKGROUND: The prevalence and predisposing factors of asymptomatic sensitization to Hymenoptera venom marker allergens are largely unknown. OBJECTIVE: To evaluate sensitization profiles in a group of 490 dermatologic patients without a history of sting-induced anaphylaxis. METHODS: Clinical data were collected using a structured questionnaire; sera were tested for total IgE and specific IgE to venom preparations, recombinant venom marker allergens, inhalative allergens, and cross-reactive carbohydrate determinants. RESULTS: The lifetime prevalence of Hymenoptera stings was 85.3%. IgE rates exceeding cut-off values of 0.35 kUA /L were 17.3% for rVes v 1, 18.0% for rVes v 5, and 3.5% for rApi m 1. Median specific/total IgE ratios for the above mentioned marker allergens were 0.05%, 0.02%, and 0.00%, respectively. Marker allergen-directed sensitization was detectable in 85.5% of 138 Vespula venom-reactive sera. Of 68 bee venom-reactive participants, 23.5% were sensitized to rApi m 1 and 64.7% to any one or several of five commercially available bee venom allergens. Although double reactivity to bee and Vespula venom was clearly associated with sensitization to cross-reactive carbohydrate determinants (P < 0.001), sensitization to marker allergens of both species was detectable in most double-reactive sera (56.5%). Vespula venom marker allergen-directed sensitization was associated with recent stings (P = 0.010), large local reactions (P = 0.009), total IgE elevation (P < 0.001), and sensitization to cross-reactive carbohydrate determinants (P = 0.008). CONCLUSIONS AND CLINICAL RELEVANCE: The high sensitization rates observed in individuals without a history of sting-induced anaphylaxis as well as total IgE levels and cross-reactive carbohydrate determinant-directed reactivity as potential confounders need to be considered in any interpretation of positive test results for Hymenoptera venom marker allergens.