Influence of blood transfusions on surgery-induced immune changes in colorectal carcinoma

Perioperative blood transfusions have been shown to enhance recurrence rates in patients with operable solid tumors, perhaps by inducing immunosuppression through unknown mechanisms. Since the surgical treatment per se has been proven to induce immune alterations, the present study was carried out to evaluate the immune effect of blood transfusions on surgery-induced immune variations. The study included 27 patients with resectable colorectal carcinoma, 18 of whom received no transfusion, while the other 9 received blood transfusions in the perioperative period. Total lymphocytes, total T lymphocytes (CD3) and soluble IL-2 receptor serum levels (SIL-2R) were measured on venous blood samples collected from each patient either before or 7 days after surgery. Both in non transfused and in transfused patients, SIL-2R mean levels were significantly higher after than before surgery. Their increase was associated with a significant decrease in both lymphocytes and CD3 cells in non-transfused patients, while in the transfused ones lymphocytes and CD3 cells did not show significant changes with surgery. This study shows that blood transfusions modify the relation between changes in SIL-2R and those in lymphocyte number induced by major surgery. It remains to be understood which relation exist between these immune effects and the promoting action of blood transfusion on relapse frequency in cancer.