Protection against anaphylaxis in hymenoptera-sensitive patients by passive immunization.

Passive administration of specific immunoglobulin led to a transient rise in antiphospholipase IgG. An observed rise of 2 microgram/ml (twofold in three cases) was associated with a very diminished response to bee venom. This did not prevent the patient's own IgG response to challenge, which was at least as good as that of non-infused patients. The infusion of IgG cannot be proposed at present as a routine mode of therapy in insect allergy. However, we present the results of our study as the best evidence to date that blocking antibody is protective.