A GENERAL EXTRACORPOREAL IMMUNOADSORPTION METHOD TO INCREASE TUMOR-TO-TISSUE RATIO

The idea of applying extracorporeal immunoadsorption (ECIA) in radioim munodiagnosis and radioimmunotherapy 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 colu mn. Athymic rats heterotransplanted with either human melanomas or hum an lung carcinoma were injected with iodine-125-labeled biotinylated 9 6.5 or L6 MoAb, respectively. At 24 or 48 hours after the injection, E CIA was performed by pumping blood through a hollow-fiber plasma filte r. The separated plasma then was passed through an absorbent (avidin-a garose) column. The whole ECIA procedure lasted for 3 hours. By this E CIA method, the tumor-to-normal tissue ratios were increased in variou s tissues (i.e., radiosensitive and blood rich organs) by a factor of four to five. Cancer 1994; 73:1033-7.