Clinical and immunological studies were conducted in fifty insect-sensitive patients receiving bee and yellow jacket venom immunotherapy. All patients had had anaphylactic reactions and had elevated serum levels of venom-specific IgE (RAST) prior to therapy. Venom injections were given weekly starting at a dose of about 0.001 μg and aiming for a maximum of 50 μg or greater. Maintenance injections were administered monthly.
In the majority of patients, venom-specific IgG was produced by immunizing doses above 1 μg. Highest titres were related to higher doses. Almost all patients receiving doses of 50 μg of venom had an IgG antibody response.
Sequential measurements of venom-specific IgE were done in thirty-seven patients. Twenty-two had a declining titre, ten had a persistently elevated titre and five patients had a rise in antibody titre. There was no relationship between IgE and IgG antibody titres except for four patients who had a marked rise of both antibodies following venom therapy. Ten of the fifty patients received subsequent stings with no reactions. At the time of the subsequent uneventful sting, all but one had detectable serum IgG antibodies.
These studies suggest: (1) venom immunotherapy appears effective for immunization of insect-sensitive individuals; and (2) considerable variability in individual immunological response to therapy and thus the probable need to individualize the degree and extent of venom therapy.