Production and kinetics of interleukin-1 in hemodialysis. In vivo and in vitro study.

Interleukin-1-beta (IL-1-beta) was measured in the plasma and peripheral blood mononuclear cell lysates of uremic patients undergoing maintenance hemodialysis by means of either cuprophane or polysulfone membranes. Basal plasma levels of IL-1-beta in hemodialyzed patients were strikingly higher than those of uremic patients on conservative treatment or of healthy subjects. Plasma levels of IL-1-beta in uremic patients increased significantly after 3 and 6 months of hemodialysis. The study of the kinetics of IL-1-beta concentration during a single hemodialysis session revealed that the concentration of IL-1-beta fell to 21 and 22% of the predialysis level with cuprophane and polysulfone, respectively. Hemodialysis patients also had a significantly higher intracellular IL-1-beta level than normal controls. During the hemodialysis session, an increase in cell-associated IL-1-beta was seen regardless of the membrane employed. In a parallel study, normal mononuclear cells were subjected to closed-loop in vitro dialysis with either cuprophane or polysulfone membranes, with or without acetate buffer. After 120 min of recirculation, an increase in cell-associated IL-1-beta was detected, but no changes were seen in the circulating medium. IL-1-beta production was not significantly influenced by either membrane or the dialysate composition. Hemodialysis has been associated with high plasma- and cell-associated IL-1 levels. The kinetics of intradialytic changes of IL-1-beta levels make IL-1 an unlikely cause of acute complications in hemodialysis. On the other hand, a chronic elevation of IL-1 in plasma of patients on maintenance hemodialysis may contribute to the development of some of the long-term complications of this treatment.