Immunoradioactive Agent against Cancer

Abstract

An antiserum to Ehrlich carcinoma in Balb/c mice, produced by immunizing rabbits, was found after appropriate absorptions to bind specifically to the tumour cells in vitro. Binding was confirmed by immunofluorescence and radioactive tracing; in the presence of complement the serum was also observed to be cytotoxic to tumour cells in vitro. Mice inoculated with Ehrlich ascites cells which had been incubated with the gammaglobulin fraction of this antiserum coupled with 131I did not develop tumour, and have remained healthy for several weeks. In contrast, mice inoculated with tumour alone or with tumour incubated with noniodinated antiserum, with or without complement, or with iodinated nonimmune globulin invariably developed ascites tumour and died within 14 days of inoculation. ADDENDUM.-Since going to press one of the four surviving mice, which received Ehrlich ascites tumour treated with the antitumour globulin coupled with 131I, died six weeks after inoculation. At necropsy no tumour was identified anywhere in the body, and death is attributed to extensive bronchopneumonia, the precise cause of which could not be ascertained; there was no histological evidence of significant radiation damage to abdominal organs or bone marrow. The other three surviving mice are still alive and free from any sign of tumour at ten weeks. © 1967, British Medical Journal Publishing Group. All rights reserved.