Development of anti-idiotypic antibodies against tumour antigens and autoantigens in ovarian cancer patients treated intraperitoneally with mouse monoclonal antibodies.

Repeated intraperitoneal administration of therapeutic amounts of radiolabelled (iodine-131) murine monoclonal antibodies leads to the development of an immune response in the recipient, part of which is directed against the variable region (idiotype) of the administered antibody (anti-Id1 response). Human immunoglobulin purified from these patients inhibits binding of the original murine monoclonal antibody to its target tumour antigen and therefore represents an "internal image" of the tumour antigen. Furthermore, this study recorded the development of human antibodies that themselves bind to the tumour antigen, with a specificity identical or similar to that of the injected monoclonal antibody. These human antitumour antibodies are probably generated by way of the idiotypic network and confirm the existence of the idiotypic network. Accompanying this antitumour response the transient development of autoantibodies that react with connective tissue components of liver, kidney, spleen, and diaphragm was also observed.