Correlation Between IL-17A And Postoperative Cognitive Dysfunction In Elderly Patients Undergoing Abdominal Surgery

Objective To investigate the correlation between the changes of serum IL-17A and postoperative cognitive dysfunction in elderly patients undergoing abdominal surgery and the influence of propofol on the postoperative dysfunction of elderly patients with gastric carcinoma and its mechanism.Methods To investigate the correlation between IL-17A and other inflammatory cytokines and postoperative cognitive dysfunction(POCD).50 elderly patients with abdominal surgery were divided into group POCD(group P)13 cases and group non-POCD(group non-P)37 cases.The levels of IL-17A,TGF-β,IL-6 and TNF-αof all the cases were determined with enzyme linked immunosorbent assay(ELISA)at 10minutes before anesthesia(T0),30 minutes after operation(T1),1 day after operation(T2)and 3 days after operation(T3).All patients were evaluate cognitive function at preoperative 1d and postoperative 7d,and the Z score was used to determine POCD.To investigate the effects of different concentrations of propofol on the level of IL-17A secreted by peripheral blood lymphocytes,20 elective surgery patients with ASA grade I were selected and 10ml venous blood was collected before anesthesia.peripheral blood lymphocytes were collected by density gradient centrifugation and was adjusted 1×10~6/ml,and then 7 groups were established including the blank group(group K),group control C(IL-1β10ng/ml),group control E(IL-1β10ng/ml and fat emulsion 10μg/ml),group P1(IL-1β10ng/ml and propofol 15μg/ml),group P2(IL-1β10ng/ml and propofol10μg/ml),group P3(IL-1β10ng/ml and propofol 5μg/ml),group P4(IL-1β10ng/ml and propofol 2.5μg/ml).The levels of IL-17A in the supernatant collected after incubated3h,12h and 24h respectively were determined by ELISA.To investigate the effect of dosage controlled propofol on the cognitive function of aged patients with gastric cancer after operation,120 patients with gastric cancer were randomly divided into 4 groups,group B1(propofol 2.5μg/ml),group B2(propofol 3.5μg/ml),group B3(propofol 5μg/ml)and group S(inhalation anesthesia control),30 cases each group.The levels of serum IL-6,IL-17A,TGF-β,Aβ1-42 were detected by ELISA at different time including before anesthesia induction(T5),postoperative 6h(T6),postoperative 1d(T7),postoperative 3d(T8),postoperative 7d(T9).The cognitive function was assessed by MMSE scale combined with MOCA scale.Results The results of the correlation of IL-17A and other inflammatory cytokines and postoperative cognitive dysfunction are as follows:The general conditions during the perioperative period and preoperative cognitive function between group P and group non P had no significant difference(P>0.05).Compared with preoperative,the values of verbal learning test,delayed memory,word interference,line position identification,digital span memory and digital connection decrease(P<0.05).There is no differences between preoperative and postoperative in cognitive function of group non P(P>0.05).Compared with preoperative,the levels of IL-6,TNF-αand TGF-βwere significantly increased in both group P and group non P(P<0.05).Compared with group non P,preoperative IL-17A,IL-6,TNF-α,TGF-βchange no greatly(P>0.05),the levels of IL-17A at T1-T3increased significantly(P<0.05),the levels of IL-6 and TNF-αat T1 and T2 increased significantly(P<0.05)and the levels of TGF-βat T3 increased significantly(P<0.05).Analysis of the correlation btween inflammatory cytokines and cognitive function showed that the levels of IL-6,TNF-alpha at T1 is related to composite Z(P=0.003,r=0.413,P=0.012,r=0.352),the levels of IL-17A at T2 is related to composite Z(P=0.011,r=0.358),and the levels of TGF-βat T3 is related to composite Z(P=0.000,r=0.593).To investigate the effects of different concentrations of propofol on peripheral white blood cells secreting IL-17A,we found that compared with 3h,the levels of IL-17A of group P1-P4,group K,group C and group E at 12h and 24h increased(P<0.05).Compared with group K,the levels of IL-17A of group C and group E at 3h 12h and 24h increased significantly(P<0.01).There is no difference of IL-17A between E group and C at 3h,12h,24h(P>0.05).Compared with group C,the levels of IL-17A of P1-P4 at 3h,12h and 24h decreased(P<0.05).Compared with group P1,the levels of IL-17A of P2-P4 at 3h,12h and 24h were lower(P<0.05).Compared with group P2,the levels of IL-17A of P3 and P4 at 3h,12h and 24h decrease(P<0.05).there is no deference in the levels of IL-17A at3h,12h and 24h between group P3and group P4(P>0.05).To investigate the effects of different concentrations of propofol on postoperative cognitive function in elderly patients with gastric cancer,we found that compared with T5,the levels of IL-6,IL-17A and TGF-beta at T6-T8 and Aβ1 at T7 and T8 of all the four groups increased(P<0.05).Compared with group S,the levels of IL-6,IL-17A,Aβ1-42and TGF-βat T6-T8 in group B1,B2 and B3(P<0.05).Compared with group B3,the levels of IL-17A at T6-T8 and the levels of IL-6,IL-17A,Aβ1-42 and TGF-βat T7and T8 of group B1 and B2 decreased(P<0.05).The levels of IL-6,IL-17A,Aβ1-42,TGF-βhave no difference between group B1 and B2 at each time point of(P>0.05).Compared with group T4,MOCA score and MMSE score of group B1-B3 and group S at T6-T8 decreased(P<0.05).Compared with group S,MOCA score and MMSE score of group B1-B3 at T7-T9 increased(P<0.05).Compared with group B3,MOCA score and MMSE score of group B1,B2 at T7-T9 increase(P<0.05).There is no difference of MOCA score and MMSE score at each time between group B1 and B2(P>0.05).Compared with group S,incidence of POCD of group B1-B3 at T7-T9 decrease significantly(P<0.05).Compared with group P3,incidence of POCD of group P1 and P2at T7-T9 decrease significantly(P<0.05).Compared with group B2,The incidence of POCD of group B1 decrease,but the difference was not obvious(P>0.05).Conclusion The level of IL-17A is positive related to the morbidity of POCD in elderly patients suffered abdominal surgery.Propofol can inhibit peripheral blood lymphocytes secreting IL-17A.Clinical controlled infusion of propofol 2.5μg/ml and 3.5μg/ml can inhibit IL-17A and other inflammatory cytokines to reduce the morbidity of POCD in elderly patients with gastric cancer.