PATHOPHYSIOLOGICAL ROLE OF CYTOKINES IN C ARDIOPULMONARY BYPASS

The state of the art of synthesis, action and pathophysiological role of cytokines in heart surgery with cardiopulmonary bypass (CPB) and in graft rejection will be presented by this mini review. Actual origina l and review publications as well as own studies in 30 patients of the Department of Thoracic and Cardiovascular Surgery of the University o f Munster/Germany provide the data base for this contribution. Heart s urgery with CPB induces systemic inflammatory reactions in which cytok ines, such as TNF-alpha, IL-2, IL-6 and IL-8, play a dominant role. Th e cytokine synthesis is triggered in the first place by activated comp lement factors and by intestinal endotoxins entering the circulation. The degree of cytokine generation correlates with the degree of the su rgical insult and the duration of the CPB. Besides other functions, cy tokines are important mediators of the interaction between leukocytes and the endothelium; this interaction converts to a crucial pathomecha nism, especially in graft rejection. Appearance and concentration of p roinflammatory cytokines in the circulation reflect the degree of the systemic inflammatory response and may predict possible complications. Graft rejection, however, is not indicated by typical patterns of cir culating cytokines or cytokine receptors, but is characterized by an e nhanced local expression of the adhesion molecules ICAM-1 and VCAM-1 i n the graft.