Background: Immunoglobulin (Ig) E–mediated sensitization to N-glycans (cross-reactive carbohydrate determinants, CCDs) may induce double IgE reactivity to honeybee venom (HBV) and yellow jacket venom (YJV) in patients who are monosensitized to either of these venoms. Alcohol consumption is associated with increased IgE levels and possibly with sensitization to CCDs in the general population.

Objectives: This study investigated the factors associated with double (HBV and YJV) IgE reactivity in patients who are allergic to Hymenoptera venom, and in particular, alcohol consumption.

Methods: Ninety-one patients with Hymenoptera allergy (68 to HBV, 19 to YJV, and 4 to both venoms) were studied. Determinations included a multiallergen IgE test and IgE to HBV, YJV, natural (glycosylated) HBV phospholipase-A2 (nPLA2), recombinant (nonglycosylated) HBV phospholipase-A2 (rPLA2), MUXF (the N-glycan from bromelain), natural (glycosylated) rubber latex, total IgE. Double reactivity was
defined as an IgE level >0.35 kUA/L to HBV and YJV.

Results: Double reactivity was observed in 28/87 (32%) clinically monosensitized patients. Double reactivity was associated with high levels of total IgE, MUXF-specific IgE, nPLA2-specifi c IgE, latex-specific IgE, and false-positive results in the multiallergen IgE test, but not with rPLA2-specific IgE. Alcohol consumption was associated with double reactivity and with high levels of IgE to glycosylated allergens after adjusting for confounders in the multivariate analysis.

Conclusions: Sensitization to CCDs and clinically irrelevant double (honeybee and wasp) IgE reactivity are common among Hymenoptera venom–allergic patients who drink alcohol. A simple questionnaire about alcohol consumption could be useful when interpreting levels of specific IgE in these patients.

Key words: Hymenoptera venom allergy. Carbohydrate epitopes. Environmental factors. Immunoglobulin E. Cross-reactivity. Alcohol.