Evaluation of commercial imported fire ant extracts by crossed immunoelectrophoresis and radioallergosorbent test.
Imported fire ant whole-body extracts (IFAWBE) from three major U.S. commercial suppliers and a reference IFAWBE and imported fire ant venom (IFAV) preparation were compared by crossed immunoelectrophoresis and RAST-inhibition testing. Results of crossed immunoelectrophoretic studies showed major differences in antigen content between commercial preparations. IFAWBE and IFAV RAST-inhibition testing showed that no commercial extract had equivalent inhibitory activity to the reference IFAWBE. Reference IFAWBE reached 50% inhibition of IFAWBE and IFAV RAST at 52 and 492 micrograms/ml, respectively. IFAV gave 50% inhibition of IFAWBE and IFAV RAST at 5.9 and 58 micrograms/ml, respectively. Of the commercial extracts, only those from one supplier were able to reach 50% inhibition of the reference IFAWBE RAST, and no commercial extract from any supplier was able to reach 50% inhibition of IFAV RAST. Analysis of inhibition slopes and intercepts confirmed that there were both qualitative and quantitative differences among the commercial extracts and the reference IFAWBE and IFAV. Our findings suggest possible reasons why some individuals fail to respond to testing or immunotherapy with IFAWBE and show the urgent need for standardization of allergenic extracts for diagnosis and treatment of imported fire ant sensitivity.
Butcher
B T
BT
Department of Medicine, Tulane University Medical Center, New Orleans, LA 70112.
Reed
M A
MA
D000485:Allergens / Q000302:isolation & purification* / Q000592:standards; D000818:Animals; D000862:Ant Venoms / Q000032:analysis* / Q000276:immunology / Q000592:standards; D001000:Ants / Q000276:immunology*; D001180:Arthropod Venoms / Q000032:analysis*; D001667:Binding, Competitive; D007106:Immune Sera; D007122:Immunoelectrophoresis / Q000592:standards; D007123:Immunoelectrophoresis, Two-Dimensional / Q000592:standards; D011506:Proteins / Q000302:isolation & purification; D011817:Rabbits; D011852:Radioallergosorbent Test / Q000592:standards; D012015:Reference Standards
D000485:Allergens; D000862:Ant Venoms; D001180:Arthropod Venoms; D007106:Immune Sera; D011506:Proteins