The culprit insect but not severity of allergic reactions to bee and wasp venom can be determined by molecular diagnosis

BACKGROUND: Allergy to bee and wasp venom can lead to life-threatening systemic reactions. The identification of the culprit species is important for allergen-specific immunotherapy. OBJECTIVES: To determine a panel of recombinant bee and wasp allergens which is suitable for the identification of bee or wasp as culprit allergen sources and to search for molecular surrogates of clinical severity of sting reactions. METHODS: Sera from eighty-seven patients with a detailed documentation of their severity of sting reaction (Mueller grade) and who had been subjected to titrated skin testing with bee and wasp venom were analyzed for bee and wasp-specific IgE levels by ImmunoCAP(TM). IgE-reactivity testing was performed using a comprehensive panel of recombinant bee and wasp venom allergens (rApi m 1, 2, 3, 4, 5 and 10; rVes v 1 and 5) by ISAC chip technology, ImmunoCAP and ELISA. IgG(4) antibodies to rApi m 1 and rVes v 5 were determined by ELISA and IgE/IgG(4) ratios were calculated. Results from skin testing, IgE serology and IgE/IgG(4) ratios were compared with severity of sting reactions. RESULTS: The panel of rApi m 1, rApi m 10, rVes v 1 and rVes v 5 allowed identification of the culprit venom in all but two of the 87 patients with good agreement to skin testing. Severities of sting reactions were not associated with results obtained by skin testing, venom-specific IgE levels or molecular diagnosis. Severe sting reactions were observed in patients showing < 1 ISU and < 2kU(A)/L of IgE to Api m 1 and/or Ves v 5. CONCLUSION: We identified a minimal panel of recombinant bee and wasp allergens for molecular diagnosis which may permit identification of bee and/or wasp as culprit insect in venom-sensitized subjects. The severity of sting reactions was not associated with parameters obtained by molecular diagnosis.