Antibodies to purified bee venom proteins and peptides. I. Development of a highly specific RAST for bee venom antigens and its application to bee sting allergy.

IgE antibodies to purified proteins and peptides from honeybee venom have been measured by the RAST. Trace amounts (less than 0.1%) of the major venom protein phospholipase A2 (PLA2) grossly distorted the measurement of IgE antibody to the other venom proteins, acid phosphatase (Acid P) and hyaluronidase (HYAL), and overemphasized their importance. Reduction of antigen coupled to the cellulose paper discs, which were used in the assay, diluted out the contaminating PLA2 without apparent loss in sensitivity. The reduction of disc-bound antigen increased the competition between IgE and IgG antibodies but did not affect measurement of IgE antibodies in sera taken from 35 untreated patients who had a history of general allergic reactions to bee stings. In 54% of sera from bee venom--allergic patients, the greatest IgE antibody response was to PLA2. In all, IgE antibodies to PLA2 were present in 91% of these sera. IgE antibodies to Acid P, HYAL, or melittin were present in 60%, 51%, and 31% of sera, respectively, and accounted for the highest level of binding in 17%, 17%, and 6% of these. Only 6% of sera were positive for whole venom but negative for the isolated antigens. A low level of IgE antibody was found to peptide 401 in 6% of sera. No IgE antibodies were found to apamin. While confirming the central role played by PLA2 in bee sting allergy, these results show that other venom components are also important in some patients.