Objective To explore the detrimental influence of normothermic and hypothermic cardiopulmonary bypass during open-heart surgery on immunity function,cytokines and complements.Methods Forty patients with congenital or rheumatic heart disease were randomized to receive the two strategies:normothermic CPB(study group)and hypothermic CPB(control group),20 cases in each group.Venous blood samples were collected at each time points of preoperation,end of CPB,day 1,4,7,14 postoperatively to examine the plasma level of IL-2,TNF-α,C3,C4,IgG,IgM,IgA,CD3,CD4,CD8.Results IL-2 in both groups decreased significantly at day 1,4,and returned to normal at day 7 postoperatively.IL-2 in control group was significantly lower than that in study group postoperatively.TNF-α in two groups was all higher at time points of end of CPB,day 1,4 postoperatively;in study group,it returned to normal level at day 7 postoperatively,whereas in control group,it was still higher at day 7 postoperatively than that before operation,and returned to normal at day 14 postoperatively.C3 in study group was significantly lower at time points of end of CPB,day 1,7 postoperatively than that in control group;C3 in both groups was all higher at time points of end of CPB,day 1,4 postoperatively;in study group,it returned to normal level at day 7 postoperatively,whereas in control group,it was still higher at day 7 postoperatively than that before operation and returned to normal at day 14 postoperatively.C4 in study group at time points of end of CPB,day 1 postoperatively was significantly lower than that in control group;C4 in both groups was all lower at time points of end of CPB,day 1,4 postoperatively than that before operation.The results showed that IgA after operation in both groups was significantly lower than that before operation,and returned to normal at day 7 postoperatively;IgA in study group at day 1 postoperatively was higher than that in control group.IgG in both group at time points of end of CPB,day 1,4 postoperatively was significantly lower than that before operation.IgG in control group was significantly higher at time points of end of CPB,day 1,4 postoperatively was significantly higher than that in control group.IgM in study group was significantly lower at time points of end of CPB,day 1,4 postoperatively.In control group,IgM was significantly lower at time points of end of CPB,day 1,4,7 postoperatively and returned to normal at day 14 postoperatively.IgM in study group was significantly higher at day 1,4 postoperatively than that in control group.CD3,CD4 in both groups decreased significantly at time points of end of CPB,day 1,4,and CD3、CD4 in study group and CD3 in control group returned to normal at day 7 postoperatively,CD4 in control group still lower than that before operation at day 7 postoperatively,and returned to normal at day 14 postoperatively.CD3,CD4 in control group was significantly lower at time points of end of CPB,day 1,4 than that in study group.CD8 in both groups increased significantly at day 1 postoperatively;there was no significant difference between the two groups.Conclusions The detrimental influence of open-heart surgery under normothermic CPB on humoral and cellular immunity function,cytokines and complements is less than that under hypothermic CPB,so normothermic CPB is beneficial for the postoperative recovery and anti-inflammation function. Objective To explore the detrimental influence of normothermic and hypothermic cardiopulmonary bypass during open-heart surgery on immunity function, cytokines and complements. Methods Forty patients with congenital or rheumatic heart disease were randomized to receive the two strategies: normothermic CPB (study group) and hypothermic CPB (control group), 20 cases in each group. Vousous blood samples were collected at each time points of preoperation, end of CPB, day 1,4,7,14 postoperatively to examine the plasma level of IL-2, TNF-a , C3, C4, IgG, IgM, IgA, CD3, CD4, CD8.Results IL-2 in both groups showed significantly decreased at day 1,4, and returned to normal at day 7 postoperatively. IL- 2 in control group was significantly lower than that in study group postoperatively.TNF-α in two groups was all higher at time points of end of CPB, day 1,4 postoperatively; in study group, it returned to normal level at day 7 postoperatively, but in control group, it was still higher at day 7 postoperatively than that before operation, and returned to normal at day 14 postoperatively. C3 in study group was significantly lower at time points of end of CPB, day 1,7 postoperatively than that in control group; C3 in both groups was all higher at time points of end of CPB, day 1,4 postoperatively; in study group, it returned to normal level at day 7 postoperatively, but in control group, it was still higher at day 7 postoperatively than that before operation and returned to normal at day 14 postoperatively. C4 in study group at time points of end of CPB, day 1 postoperatively was significantly lower than that in control group; C4 in both groups was all lower at time points of end of CPB, day 1,4 postoperatively than that before control operation. that IgA after operation in both groups was significantly lower than that before operation, and returned to normal at day 7 postoperatively; IgA in study group at day 1 postoperatively was higher than that in control group. IgG in both group at time points of end of CPB day 1,4 postoperatively was significantly lower than that before operation. IgG in control group was significantly higher at time points of end of CPB, day 1,4 postoperatively was significantly higher than that in control group. IgM in study group was significantly lower at time points of end of CPB, day 1,4 postoperatively.In control group, IgM was significantly lower at time points of end of CPB, day 1,4,7 postoperatively and returned to normal at day 14 postoperatively. IgM in study group was significantly higher at day 1,4 postoperatively than that in control group. CD3, CD4 in both groups showed significantly at time points of end of CPB, day 1,4, and CD3, CD4 in study group and CD3 in control group returned to normal at day 7 postoperatively, CD4 in control group still lower than before before operation at day 7 postoperatively, and returned to normal at day 14 postoperatively. CD3, CD4 in control group was significantly lower at time points of end of CPB, day 1,4 than that in study group.CD8 i n both groups increased significantly at day 1 postoperatively; there was no significant difference between the two groups. Conclusions The detrimental influence of open-heart surgery under normothermic CPB on humoral and cellular immunity function, cytokines and complements is less than that under hypothermic CPB, so normothermic CPB is beneficial for the postoperative recovery and anti-inflammation function.