Increases in leukocyte cluster of differentiation antigen expression during cardiopulmonary bypass in patients undergoing heart transplantation.

Cardiopulmonary bypass (CPB) is essential in heart transplantation surgery. It is also used in coronary artery grafting surgery where it has been associated with a postoperative inflammatory response. This manifests as an increase in pro-inflammatory proteins like interleukin-8 and tumour necrosis factor alpha accompanied by increases in neutrophil populations and increased expression of cluster of differentiation (CD) antigens. The latter have been investigated using flow cytometry, which is limited to the measurement of three to four CD antigens simultaneously. We have developed a novel antibody array that can simultaneously measure the expression of 72 different CD antigens. The purpose of this study was to use this technology to measure CD antigen expression in patients undergoing CPB during heart transplantation. Twelve patients undergoing this operation were studied. A preoperative sample acted as an internal control while a second sample taken during CPB was the comparator. No previous studies have examined changes in CD antigen expression during heart transplantation. We report an increase in the expression of 10 different CD antigens across all patients between the two time points.