Biological activities of anti-IgE antibodies.

Naturally occurring anti-IgE autoantibodies represent a heterogeneous mixture of antibodies with diverse specificities and biological functions. By using murine monoclonal anti-IgE autoantibodies directed against different epitopes on the IgE molecule as a model for autoantibodies, we could show that only a minority of antibodies combine all beneficial biological activities, such as the activity of inhibiting in vitro IgE synthesis, removing IgE from the surface of CD23+ cells and not being anaphylactogenic. While it is difficult to isolate and measure anti-IgE antibodies in human serum, it is now possible to generate such human anti-IgE antibodies by the method of repertoire cloning. Thus, human recombinant antibodies against IgE may become available for the treatment of atopic disease.