[Radiolocalization of human hepatoma with anti-human hepatoma monoclonal antibodies and its F(ab')2 in tumor-bearing nude mice].

This paper reports the results and procedures for the radiolocalization of human hepatoma by murine MAb (HAb 18) and its F (ab')2 in animal model. 131I-labelled HAb 18 IgG and 125I-labelled its F(ab')2 were intravenously injected respectively to human hepatoma bearing nude mice. Clear tumor imaging manifested 48 hrs. after injection of 125I-labeled F(ab')2 and 120 hrs. after 131I-labeled intact MAb. The animals were killed 48, 72, 120, and or 168 hrs. after injection respectively. Bound radioactivity was counted in a variety of solid organs. Tumor: liver ratios for intact MAb or its F(ab')2 were greater than those for unrelated MAb at each time points, the differences being greatest after 168 hrs. (ratio intact MAb 5.15 +/- 0.64, ratio unrelated MAb 0.93 +/- 0.16) and after 48 hrs. (ratio F(ab')2 14.47 +/- 2.35, mean +/- sd). The amount of I-MAb bound was greater in the tumor than in any other solid organ. The clearance rate of F(ab')2 was faster then that of intact MAb. It was shown that HAb 18 MAb may be of value as an immunodiagnostic agent for hepatoma.