Demonstration of auto-anti-idiotypic antibody cross-reacting with public idiotypic determinants in the serum of rye-sensitive allergic patients.

The present study documents the presence, in the serum of one allergic individual, of auto-anti-idiotypic antibodies cross-reacting with public idiotypic determinants expressed on human IgE and IgG anti-Rye I antibodies. Sera from rye-sensitive patients were tested for specific IgG and IgE antibodies to Rye I by double antibody. The IgG fraction, isolated from the serum of a patient with a history of previous hyposensitization therapy, was repeatedly absorbed on Rye-I-Sepharose as well as on IgM- and IgG-Sepharose to remove anti-Rye I antibodies as well as any possible anti-heavy or light chain activity. This IgG fraction, named anti-idiotypic fraction (a-IdF), blocked in a dose-dependent fashion the reaction of IgG and IgE anti-Rye I antibodies with Rye I antigen. The a-IdF also blocked the binding of anti-rye antibodies to Rye I antigen in the serum of 20 unrelated allergic patients, indicating that these anti-Rye I antibodies bore public idiotypic determinants.