Effects of perioperative low-dose naloxone on the immune system in patients undergoing laparoscopic-assisted total gastrectomy: a randomized controlled trial

Low immune function after laparoscopic total gastrectomy puts patients at risk of infection-related complications. Low-dose naloxone (LDN) can improve the prognosis of patients suffering from chronic inflammatory diseases or autoimmune diseases. The use of LDN during perioperative procedures may reduce perioperative complications. The purpose of this study was to examine the effects of LDN on endogenous immune function in gastric cancer patients and its specific mechanisms through a randomized controlled trial. Fifty-five patients who underwent laparoscopic-assisted total gastrectomy were randomly assigned to either a naloxone group (n = 23) or a nonnaloxone group (n = 22). Patients in the naloxone group received 0.05 µg/kg-1.h naloxone from 3 days before surgery to 5 days after surgery via a patient-controlled intravenous injection (PCIA) pump, and patients in the nonnaloxone group did not receive special treatment. The primary outcomes were the rates of postoperative complications and immune function assessed by NK cell, CD3 T cell, CD4 T cell, CD8 T cell, WBC count, neutrophil percentage, and IL-6 and calcitonin levels. The secondary outcomes were the expression levels of TLR4 (Toll-like receptor), IL-6 and TNF-α in gastric cancer tissue. Compared with the nonnaloxone group, the naloxone group exhibited a lower incidence of infection (in the incision, abdomen, and lungs) (P