The role of IgG4 as blocking antibodies in asthmatics and in bee keepers.

Sera from 40 asthmatic patients and from 77 bee keepers were evaluated by solid-phase radioimmunoassay for their allergen-specific IgG4 antibody levels. The results indicated that allergen-specific IgG4 antibodies become prominent upon repeated parenteral stimulation with antigen, i.e. immunotherapy and bee stings, and suggested the possible association of IgG4 with blocking antibodies in these allergic conditions.