Cardiopulmonary bypass, steroid administration, and surgical injury synergistically impair memory T cell function and antigen presentation.

Previous reports showed that cardiac surgery with cardiopulmonary bypass (CPB) impair cell-mediated immunity by using antigen-non-specific responses. This study elucidated the effects of cardiac surgery with CPB on antigen-specific immunity. Twenty patients who underwent elective cardiac surgery using CPB were randomly divided into two groups: group A (n=10) and group B (n=10) with and without steroid administration, respectively. Group C patients underwent off-pump CABG (n=8). Peripheral blood mononuclear cells (PBMCs) were taken before and after surgery. Proliferation responses to pure protein derivative antigen were measured. The effects of CPB and steroid on T cell response and antigen-presentation were assessed by cross-stimulation between the preoperative and the postoperative PBMCs. Antigen-specific T cell responses decreased to about 5% of the preoperative values immediately after surgery with CPB, regardless of steroid administration. The T cell response in group B on POD 7 was significantly higher than that in group A. CPB impaired mainly T cell responses, and steroid administration enhanced impairment of T cell response and antigen-presentation. Open-heart surgery with CPB severely impaired antigen-specific immunity. Steroid administration enhanced the impairment of antigen-presentation as well as T cell function, and retarded the recovery of antigen-specific immunity.