Objective: Cardiovascular surgery with extracorporeal circulation causes a systemic inflammatory response, which can lead to organ failure and increased postoperative morbidity. Advances in knowledge about the interactions between markers of cellular and humoral immunity involved in the inflammatory response to cardiopulmonary bypass (CPB) may reduce the deleterious effects and improve the outcome for patients undergoing cardiac surgery.
Methods: To determine the release of immunoinhibiting cytokines during CPB, we measured plasma levels of interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) in 30 patients undergoing elective coronary artery bypass grafting. Arterial blood samples were collected at eight time points before, during and after CPB, using a standardized ELISA-technique.
Results: Plasma IL-10 and TGF-beta increased significantly after weaning off CPB (P < 0.05) and peaked respectively at time of skin closure (IL-10, 308 +/- 180 pg/ml; TGF-beta, 1860 +/- 906 pg/ml; mean peak +/-S.D.). Postoperatively, 6 h, IL-10 decreased to 19.8 +/- 9.8 pg/ml (P < 0.05) and TGF-beta decreased to 1133 +/- 547 pg/ml (P < 0.05).
Conclusions: Both cytokines are major immunoregulatory factors with negative influence on T cell-mediated immunologic response. The significantly elevated levels at the end of CPB indicate that IL-10 and TGF-beta may be important factors of immunologic dysregulation following CPB.