Immunodepression after surgery: impaired production of interleukin 2.

The capacity of peripheral blood mononuclear cells to produce interleukin 2 (IL 2) was studied serially before and after various surgical procedures in 34 patients. In the group of 6 patients who had minor surgery and were categorized into class 1, IL 2 activity did not differ significantly from the preoperative value, throughout the postoperative course. In the group of 14 class 2 patients who underwent major surgery, however, significant decreases in IL 2 activity were observed 1, 3 and 6 days after operation as compared to findings before surgery. Preoperative levels were reverted to by the 8th postoperative day. The remaining 14 patients underwent major and extensive surgical procedures, and were put into class 3. Here too, were also significant decreases in the activity 1, 3 and 6 days after operation. The activity remained significantly depressed 8 days after surgery, in this group of patients. These results show that depression in the production of IL 2 in postoperative surgical patients correlates relatively well with the extent of the surgical procedures.