Comparison of immunological changes between subcutaneous and intravenous route of administration of IL-2 in cancer patients.

The effects of the route of administration of interleukin 2 (IL-2) on the immunological parameters of patients with various malignancies were investigated. The percent mean values for IL-2 receptor (Tac) positive cells among mononuclear cells in patients receiving IL-2 subcutaneously (5 cases) or intravenously (6 cases) were 7 and 7%, respectively. The corresponding values of post-IL-2 treatment peak were 18 and 16%. Similarly, the values for class II antigen expressing cells were 12 and 16% and 25 and 26%. In no case the difference between the values for the subcutaneous or the intravenous route reached significance. Using the 51Cr release assay, the mean percent killing activity of IL-2-activated mononuclear cells against Daudi tumour target cells for the subcutaneously and the intravenously treated groups were 27 and 14% and the corresponding values for the post-IL-2 treatment peak were 59% (p > 0.05) and 69% (p > 0.05), respectively. The similar values using K562 tumour as target were 17 and 8%, and the corresponding values for post-treatment peak were 55% (p > 0.05) and 23% (p > 0.05). In all cases the cytotoxic values for the post-IL-2 treatment were significantly greater than the pre-IL-2 values. The mean (+/- SD) values for serum beta2-m levels for 6 subcutaneously and 5 intravenously IL-2-treated patients were 6.5 +/- 4.6 and 5.7 +/- 3.4 mg/l (p > 0.05). The corresponding values for post-IL-2 (15 days) were 9.1 +/- 3.4 and 9.9 +/- 5.1 mg/1, respectively. These results demonstrate that there is no significant difference in the immunological parameters in cancer patients receiving IL-2 via subcutaneous or intravenous routes and provide further support for the current trend for clinical trials to concentrate on outpatients subcutaneous administration.