DOES THE TEMPERATURE OF CARDIOPULMONARY B YPASS AFFECT NEUTROPHIL INTERACTIONS WITH THE ENDOTHELIUM

The increasing interest in ''warm'' aerobic cardioplegia requires a cr itical reevaluation of the systemic effects of the associated normothe rmic cardiopulmonary bypass (CPB). As activated neutrophils seem to be essential mediators of the inflammatory response to CPB via the cytot oxicity of the products that are released during their adhesion to end othelial cells, the authors undertook a study of the influence of temp erature on the interaction between the neutrophils and the endothelium in 95 patients undergoing warm (31-33,5 degrees C, n = 49) and cold ( 26-27 degrees C, n = 46) CPB surgery. Blood sampling was performed bef ore, during and after CPB. The following markers of neutrophil-endocar dium interaction were analysed : complement activation (C3a), cytokine production (tumor necrosis factor alpha, interleukines 1, 6 and 8, an d interleukin-I receptor antagonist); endothelial expression of cytoki ne-dependent [intercellular adhesion molecule (ICAM)] and cytokine-ind ependent (P-selectin) adhesion molecules (P-selectin); expression of c ytokine molecules on the surface of polynuclear neutrophils (CD11a, CD 11b, CD11c): and finally, endothelial adhesion and transendothelial mi gration of neutrophils (interleukin 8 and elastase). The results showe d that, irrespective of temperature, CPB was associated with changes s trongly suggestive of phenomena of transendothelial adhesion and migra tion. Moreover, normothermia increased the intensity of the inflammato ry response as shown by increased cytokine production, earlier express ion of neutrophil adhesion molecules and increased elastase production .