Peritoneal dialysis is a method of renal replacement therapy which has been increasingly in use worldwide and, in recent years, also in our country. A factor limiting long-term use of peritoneal dialysis is the maintenance of the function of the peritoneum of as a dialysis membrane. Impair- ment of the anatomical and functional integrity of the peritoneal membrane may be due to severe or recurrent peritonitis but, also, in patients without a history of peritoneal infection, presumably as a result of contact between the peritoneum and a bioincompatible dialysis solution. When investigating the structural and functional changes in the peritoneal membrane, considerable attention was given to cytokines. The main source of cytokines in the peritoneal cavity are macrophages, mesothelial cells, and fibroblasts. In peritoneal dialysis, cytokines play a role both in defense against the development of peritoneal infection and in the course of peritoneal infecti- on. By virtue of their biological effects, cytokines may affect the permeability of the peritoneal membrane and, consequently, the efficacy of peritoneal dialysis. In addition, cytokines are relea- sed on contact of the peritoneum with the dialysis solution and may thus be made use of in biocompatibility studies. Changes of cytokine levels can be studied – when performing peritoneal dialysis in clinical practice – in the dialysis solution drained from the peritoneal cavity, in tissue cultures, and in animal experiments. The effects of cytokines are modified by the action of their soluble receptors and antagonists. Future studies are warranted to clarify the role of cytokine antagonists and their soluble receptors.

        Key words: Peritoneal dialysis - Cytokines - Biocompatibility - Dialysis solution