Cytokines and biocompatibility.

Issues in biocompatibility have traditionally focused on the interaction of membranes or materials with the activation of complement, red blood cell destruction, clotting dysfunctions, and platelet activation. Other studies are concerned with the replacement fluid formulations and host responses. Recent attention has examined the interaction of the blood monocyte with either complement or membrane surfaces. Activation of monocytes leads to the synthesis of cytokines, namely interleukin 1, tumor necrosis factor, and interleukin 6. These potent polypeptide 'cytokines' affect biological functions in nearly every tissue. Understanding the mechanisms by which gene expression of these cytokines is triggered will help in the better design of membrane material or substitution fluids. These are discussed in the context of increased cytokine synthesis during hemodialysis and continuous ambulatory peritoneal dialysis.