Suppression by methylprednisolone of augmented plasma endotoxin-like activity and interleukin-6 during cardiopulmonary bypass.

It has been reported that plasma endotoxin, measured by Limulus amoebocyte lysate assays, markedly increased during extracorporeal circulation (ECC). Therefore, this study was undertaken to see if pretreatment with methylprednisolone 30 mg kg-1 modifies the endotoxaemia and associated increases in plasma cytokines in 17 patients undergoing cardiac surgery requiring ECC. We found that methylprednisolone suppressed significantly the ECC-induced increases in plasma endotoxin, measured by a conventional Limulus amoebocyte lysate assay (Toxicolor), and interleukin-6. Plasma concentrations of endotoxin, measured by a highly specific chromogenic Limulus test (Endospecy test), tumour necrosis factor-alpha and interleukin-1 beta did not increase significantly in either the control or methylprednisolone groups.