The effect of surgical operation upon monocytes.

The effect of surgical operation upon monocyte numbers and function was studied in patients with both benign and malignant disease. In patients with benign disease a significant increase in the phagocytosis of 99Tc latex-labelled particles by monocytes was observed at 24 h postoperatively (P less than 0.01 compared with preoperatively) and also a significant increase in monocyte numbers (P less than 0.001 compared with preoperatively). In patients undergoing surgery for malignant disease no significant increase in phagocytic activity of monocytes was found postoperatively. A significant decrease in monocyte numbers was shown to follow surgery in this group (P less than 0.001). The implications of these findings are discussed.