A general extracorporeal immunoadsorption method to increase tumor‐to‐tissue ratio

Abstract

The idea of applying extracorporeal immunoadsorption (ECIA) in radioimmunodiagnosis and radioimmuno‐therapy has been proposed previously. The authors here report on the development of new concept using a general method for ECIA based on biotinylated MoAb adsorbed on an avidin column. Athymic rats heterotransplanted with either human melanomas or human lung carcinoma were injected with iodine‐125‐labeled biotinylated 96.5 or L6 MoAb, respectively. At 24 or 48 hours after the injection, ECIA was performed by pumping blood through a hollow‐fiber plasma filter. The separated plasma then was passed through an absorbent (avidin‐agarose) column. The whole ECIA procedure lasted for 3 hours. By this ECIA method, the tumor‐to‐normal tissue ratios were increased in various tissues (i.e., radiosensitive and blood rich organs) by a factor of four to five. Cancer 1994; 73:1033–7. Copyright © 1994 American Cancer Society