In vitro effect of interleukin 2 on depression of cell-mediated immune response after surgery.

Effect of exogenous interleukin 2 (IL 2) on the postoperative depression of cell-mediated immune response in vitro was studied in 8 patients with benign lesion and 11 patients with various carcinoma, undergoing major surgical procedures. When peripheral blood mononuclear cells (PBM) were obtained from patients 3 days after surgery, the proliferative response of PBM in mixed lymphocyte culture (MLC) was significantly decreased, as compared to that before operation. The depressed proliferative response was significantly increased and improved to the preoperative level, when exogenous IL 2 was added at a concentration of 50 per cent in culture. The defective generation of cytotoxic cells in MLC 3 days after operation was also significantly augmented and improved to the preoperative range by addition of 25 per cent IL 2 in culture. IL 2 produced minimal increase in these responses when PBM were obtained preoperatively. There was no significant difference between each value in these responses obtained from patients with benign lesion and carcinoma. These results show that PBM from patients who had undergone major surgery were responsive to exogenous IL 2. The postoperative depression of cell-mediated immune response may be reversible with exogenous IL 2.