THE EFFECT Of METHYLPREDNISOLONE ON THE SERUM LEVEL Of TUMOR NECROSIS fACTOR­ ALPHA (TNf-a) lN PATIENTS UNDERGOING CARDIAC VALVE REPLACEMENT

Abstract

Exposure of the blood to extracorporeal artificial surfaces during cardiopulmonary bypass induces an acute inflammatory response. The inflammatory process might be associated with morbidity caused by organ dysfunction observed after cardiopulmonary bypass.

The inflammatory response involves the release of proinflammatory cytokines including TNF-a. TNF-a is the key of all cytokines that initiates the whole inflammatory cascade. It plays an important role in the pathogenesis of the systemic inflammatory response syndrome induced by CPB. Its deleterious effects include endothelial dysfunction with enhanced vascular permeability, decreased systemic vascular resistance and myocardial depression.

Corticosteroids affect profoundly cytokine production. They negatively regulate TNF-a gene expression. Corticosteroid pretreatment before CPB has been found to reduce the risk of the postperfusion syndrome and the organ injury which follows it and to improve survival.