Allergens in Hymenoptera venom : XXI. Cross-reactivity and multiple reactivity between fire ant venom and bee and wasp venoms

Abstract

The relationships between fire ant venom and bee and wasp venoms were explored by studying sera from five groups of subjects. Group 1 included adults not allergic to any venoms and who were not exposed to fire ants. Group 2 included adults with fire ant exposure who were not allergic to venoms. Group 3 included patients with recent systemic reactions to fire ant venom. Group 4 included patients allergic to bee and vespid venoms with no fire ant exposure. Last, group 5 included patients allergic to bee and vespid venoms with fire ant exposure. None of the serum samples from group 1 was RAST reactive to fire ant venom, but 24% of those from group 2 were fire ant positive, as were 100% of those from group 3, 51% of those from group 4, and 87% of those from group 5. The RAST-positive patients in groups 2 and 5 were also skin test positive. RAST inhibition studies demonstrated cross-reactivity in some cases and multiple reactivity in others. The serum samples were further investigated via nondenaturing electrophoretic immunoblot studies and RAST with highly purified allergens. Serum samples from group 4 reacted to a single band on immunoblots and with only one of the four purified allergens from fire ant venom ( Solenopsis invicta I, or Sol i I). Serum samples from groups 2, 3, and 5 showed various patterns of allergen reactivity. All serum samples from patients allergic to fire ant venom who also reacted to bee and/or vespid venoms by RAST contained IgE antibodies binding to Sol i I. A few serum samples that did not bind to bee or vespids did not have IgE antibodies against Sol i I. Sol i I, the 37,000 dalton molecular weight allergen, is the major cross-reactive allergen of imported fire ant venom.