EXPRESSION OF ADHESION AND ACTIVATION MOLECULES ON LYMPHOCYTES DURINGOPEN-HEART-SURGERY WITH CARDIOPULMONARY BYPASS

Open-heart surgery with cardiopulmonary bypass (CPB) and abdominal sur gery are associated with lymphocytopenia. We measured a panel of adhes ion and activation molecules on lymphocytes to clarify possible associ ation of CPB with increased expression of these molecules. Eight patie nts undergoing open-heart surgery and eight with abdominal surgery wer e studied. The adhesion molecules CD11a/CD18 (LFA-1, CD11c/CD18 and CD 44 and the activation molecules CD25, CD69, CD71 and MHCII were measur ed, using monoclonal antibodies and flow cytometry. Lymphocytopenia wa s observed during CPB and for some hours after both open-heart and abd ominal surgery. The proportion of CD11a/CD18-positive lymphocytes rose from 67.6 +/- 8% to 86.4 +/- 3% after aortic declamping (p < 0.05). T he expression of activation molecules CD25, CD69 and CD71 was unchange d during and after open-heart as well as abdominal operations. Thus CP B was associated with increased expression of the adhesion molecule CD 11a/CD18 on lymphocytes, while the expression of activation molecules on lymphocytes was unchanged.