In vivo distribution of recombinant interleukin-2-activated autologous lymphocytes administered by intra-arterial infusion in patients with renal cell carcinoma.

Recombinant interleukin-2 (RIL 2)-activated autologous peripheral blood lymphocytes (PBL) were infused directly into the renal arteries of 3 patients with renal cell carcinoma, and the in vivo distribution of the infused cells was investigated. In vitro studies to define the optimal culture conditions indicated that maximal lymphokine-activated killer activity was observed at around 10-20 days in culture, as judged by the cytotoxicity against fresh allogenic tumor cells. Maximal expression of the interleukin-2 receptor was also obtained at around 10 days. PBL collected by leukopheresis from each patient were thus cultured for 10 days with RIL 2, labeled with 111In-oxine, and then infused directly into the renal artery of the affected kidney via a catheter. Radioactivity in the infused side of the kidneys increased immediately after the infusion but then gradually decreased. Radioactivity in the lungs also rapidly increased within the first hour but then cleared gradually, whereas that in the liver and spleen tended to increase steadily. Nevertheless, at 48 hours, the infused side of the kidneys retained levels of radioactivity comparable to those seen in the liver and spleen, while the levels seen in the lungs were already close to background levels. The radioactivity in the areas corresponding to tumors remained consistently higher than that in the normal parts of the affected kidneys. The direct comparison of the radioactivity distribution pattern with the macroscopic appearance of surgically resected kidneys indicated that the accumulation of radioactivity was indeed selectively associated with the tumor tissues in the kidneys, except for a case in which the tumor was quite necrotic and hypovascular. Histological examinations indicated intensive mononuclear cell infiltrations in and around the tumor tissues as well as in normal tissues in the kidneys. These preliminary results indicated that infusion of activated lymphocytes via major tumor-feeding arteries would be an extremely effective way to obtain the selective localization of effector cells in the tumor tissues.