The Activity Of NK Cells During Perioperative In Colorectal Cancer Surgical Patients Is Associated With IL-18 Under General Anesthesia

Objective: In this study,by test of the activity of natural killer cells(NK cells) and the plasma levels of IL- 18(interleukin- 18) in laparoscopic colorectal cancer operation and arthroscopic surgery during intravenous anesthesia, and observe whether the plasma concetration of IL- 18 is directly bound up with NK cells activity of the anti-tumor immune. And discuss the influence of intravenous general anesthesia to the anti-tumor immune during perioperative, then compare the differences in killing activity of NK cells between the tumor patient and non-neoplastic patient.Methods: 19 laparoscopic operation patients of colorectal cancer were selected, with American Society of Anesthesiologists Physical Status Classification(ASA class) were I~Ⅱand Dukes stage A、B; 17 arthroscopic surgery patients with ASA class I~Ⅱ were enrolled. Two groups of patients recieved the same drug at anesthesia induction and maintenance according to the uniform standard. The peripheral blood samples were taken before the induction of general anesthesia(T0), 10 min after anesthesia induction(T1), 60 min after anesthesia induction(T2), at the end of surgical suture of skin(T3).The biochemical assay of killing activity of NK cells was through the method of CCK-8, plasma concetrations of IL- 18 was measured using Enzyme-Linked Immuno Sorbent Assay(ELISA).Results:(1) The changes for the cytotoxicity of NK cells: compared each time point of two groups respectively. The killing activity of NK cells in the group of colorectal cancer(the tumor group), compared with the pre-induction of anesthesia(T0), 10 min after anesthesia induction(T1) was obviously increased(P < 0.05), but then gradually reduced. But arthroscopy group(the non-neoplastic group) is characterized significantly decreased at T1 compared with T0 and had statistical significance(P < 0.05), and then gradually recover to pre-induction levels. While the performance of T1 time in arthroscopic group(non-tumor group) was significantly lower than T0 time(P <0.05), and then gradually recover to pre-induction levels. The comparison among two groups, cytotoxicity of NK cells in tumor group was lower than non-neoplastic group at T0 time(P < 0.01), in contrast,the activity of NK cells in the tumor group was higher than non-neoplastic group at T1 moment(P < 0.05).(2) Changes of the concentrations of IL- 18: compared with T0, the serum of IL – 18 in two groups were decreasing rapidly at the first(T1) and gradually decline as time changes(T2, T3).And in the tumor group, the plasma concentrations of IL- 18 at T1 time was significantly increased in comparing with T0 time, andthere was significant difference among the two groups(P < 0.05); in non-tumor group, however,T1、T2 and T3 time point showed no statistically significantt in comparison to T0 moment.Conclusion: The NK cells’ cytotoxicity was temporary raised in Colorectal malignancy patients after induction of general anesthesia, but this increases of NK cells’ activity was suppression by the surgical stress, and IL-18 participate in the regulation of the perioperative activity of NK cells.