In vitro evaluation of blocking antibodies by RAST interference during pollen desensitization: role of the IgG fraction.

RAST interference was used to study the changes in blocking antibodies during hyposensitization. At the onset of desensitization blocking antibodies levels were correlated to IgE antibody titers. They progressively rose during the treatment. IgG isolated by adsorption onto protein A Sepharose were only a part of blocking antibodies. The isolated antibodies gave 80% of RAST interference values. Results showed that RAST interference may be used routinely to determine changes of immunological parameters of immunotherapy.