VENOM IMMUNOTHERAPY FOR HONEYBEE STING-SENSITIVE PERSONS

Preliminary studies have suggested that venom immunotherapy for Hymenoptera-sensitive persons may be superior to conventional immunotherapy with whole insect extracts. The immunological and clinical effects of honeybee venom (HBV) “rush” hyposensitization were tested in 18 patients, who received an intensive two-day course of HBV injections once monthly. Initial doses of 0.5 μg were raised as rapidly as possible to 200 μg; one to nine treatment courses were required to reach 200 μg. Anaphylactic reactions were experienced by 11/18 patients during injection therapy. Patients then returned for deliberate honeybee sting challenges. Initial sting challenges were tolerated well by 10/17 patients completing therapy; 7 other patients required epinephrine. With subsequent treatment 11/17 patients achieved complete clinical protection; partial protection was achieved by 3 others. Protection was maintained by periodic deliberate stings or by HBV injections at 2-8 week intervals. Serum IgE antibodies to HBV and to venom phospholipase-A (PLA) rose dramatically (X=350%) after therapy and remained elevated over baseline levels tn 14 patients. Serum IgG antibodies to PLA rose steadily during therapy and approximated those seen in hyperimmune beekeepers in 8 patients. There was no level of IgG antibody which was protective for all patients. The results indicate that under controlled conditions HBV immunotherapy provides clinical protection in the majority of patients.