Induction of interleukin-1 production in patients undergoing cardiopulmonary bypass.

Systemic reactions resembling inflammation occur in patients undergoing cardiopulmonary bypass. We now report that interleukin-1, an endogenous pyrogen and a key mediator of inflammation, is transiently and consistently generated in vivo by circulating monocytes within hours after cardiopulmonary bypass. Interleukin-1 production was assessed by measuring interleukin-1 functional activity and interleukin-1 beta antigen concentration in cell lysates from monocytes of patients during and after bypass.