Impaired production of interleukin-2 after surgery.

The capacity of peripheral blood mononuclear cells (PBM) to produce interleukin-2 (IL-2) was studied serially before and following operation in patients undergoing various surgical procedures. In patients who had major surgery, significant decrease in IL-2 activity was observed 1, 3 and 6 days after operation as compared to that before surgery, although there was no significant change throughout the post-operative course in patients undergoing minor surgery. IL-2 activity returned to the pre-operative level by the 8th post-operative day. However, it remained significantly depressed 8 days after surgery in patients who had undergone major surgical procedures of more increasing severity. Distribution of T cell subsets, especially OKT4 positive cells, did not differ significantly from the pre-operative value throughout the post-operative course. However, the depressed production of IL-2 3 days after surgery could be abolished when adherent cells were removed from PBM by plastic adherence procedures. These results indicated that adherent cells, but not quantitative change in T cell subsets, might be responsible for the depression of IL-2 production after surgery.