Interleukin-2 (IL-2) augments host cellular immune reactivity in the perioperative period in patients with malignant disease

Major surgery impairs cellular and humoral immunity, in particular natural cytotoxicity, and this may facilitate the dissemination of tumour cells in the peri-operative period. Recombinant interleukin-2 (rIL-2) has been used to modulate peri-operative immune function. Eighteen patients were randomized to receive either rIL-2 or placebo for three days, as a subcutaneous injection, prior to surgical resection for colorectal cancer. Natural cytotoxicity (natural killer (NK) and lymphokine-activated killer (LAK) cell activity), monocyte phagocytosis and immune cell surface activation marker (CD14+HLA-DR) expression were assessed during therapy and for up to 21 days after surgery. rIL-2 therapy enhanced both NK and LAK cell-mediated cytotoxicity and augmented circulating lymphocyte CD16⁺ and CD56⁺ cell subset populations. Circulating monocyte phagocytosis was also increased. Hence, rIL-2 may be used to enhance immune function in the peri-operative period in patients undergoing curative cancer surgery.