Allergens in Hymenoptera venoms. XXIII. Venom content of imported fire ant whole body extracts.

Abstract

A two-site immunoassay using monoclonal antibodies has been developed to measure the imported fire ant venom allergen Sol i III. The assay is specific for Solenopsis invicta venom, since one of the monoclonal antibodies does not react with Sol r III. A commercial imported fire ant whole body extract, known from RAST and skin test data to be potent, was found to contain 10.3 micrograms of Sol i III per milliliter. This was comparable to the content of an extract freshly prepared in our laboratory. The immunoassay detected Sol i III in an extract of fire ant abdomens, but not in head and thorax extract. The amount of imported fire ant venom in a potent whole body extract appears to be sufficient to provide possible protection for patients receiving it as immunotherapy, although this can only be verified by controlled clinical trials with intentional sting challenges.