Antibodies to interferon in patients undergoing IFN therapy: an update

Interferons (IFNs) are being increasingly used in the treatment of several disorders. Since the early clinical trials, it was documented that some of the patients who received IFN produced antibodies against it. Both neutralizing and nonneutralizing antibodies were detected and it was demonstrated that the development of neutralizing antibodies was often associated with a failure of the IFN therapy. This finding is not actually surprising if one considers that many papers describing natural or therapy-induced development of antibodies to IL-1, IL-2, IL-6, IL-10, G-CSF, GM-CSF, insulin, recombinant factor VIII in man have been published. Since hormones, cytokines, biological modifiers and homeostatic agents are being used for therapeutic applications, the awareness of the possibility that therapy-induced antibodies can develop in man should help define the therapeutic management of many infectious, autoimmune and neoplastic diseases. This paper will review and discuss what is currently known about the technical, biological, and clinical aspects of these "autoantibodies", with particular reference to antibodies to IFN developed during therapy.