Bumblebee allergens and cross-reactivity with honey bee:
Bumblebee venom is similar to honey bee venom but contains some unique toxins not present in honey bee venom (Table 3).42,43Bumblebee PLA2 shows only 54% sequence identity (SI) with Api m 144 explaining the often limited cross-reactivity with honey bee venom. Serine proteases represent major allergens in bumblebee venom. They are structurally different from the honey bee CUB serine protease Api m 7 showing only 33% identity.45
Seventy-three to 100% of unselected honey bee venom-allergic subjects also show IgE binding with bumblebee venom in vitro 43, 46, 47, and allergic reactions after bumblebee stings have been reported in subjects with primary honey bee venom allergy.8,10,43 However, patients with occupational bumblebee exposure may react with unique epitopes or allergens (especially serine protease) in bumblebee venom that cannot be effectively inhibited by honey bee venom.47