Dialysis fluid cytotoxicity and inhibition of host defence in cultured human mesothelial cells are neutralized rapidly with incubation in the peritoneum

Background. A recent survey puts the global dialysis population at 535 100 ; of those on peritoneal dialysis, 85% are on continuous ambulatory peritoneal dialysis. Current hyperosmolar dialysis fluids are toxic to peritoneal cells and inhibit certain host-defence functions. An alternative preparation, glucose polymer, has recently been developed. Methods. Mesothelial cell viability, interleukin-6 and prostacyclin synthesis, after exposure to 7.5% glucose polymer, 1.36% glucose or 3.86% glucose peritoneal dialysis effluent solution was assessed. Results. In its neat form, at an original pH of 5.4, glucose polymer was as toxic as hyperosmolar solutions (P<0.01). Synthesis of interleukin-6 and prostacyclin were significantly inhibited by neat dialysis fluid, (P<0.01). However, after an in vivo intraperitoneal incubation of only 15 min the toxicity of all solutions tested in vitro was lost. Conclusions. Despite rapid in situ neutralization of dialysis fluid toxicity, mesothelial injury and inhibition of host-defence function, early in the dialysis cycle, may affect peritoneal physiology given the complex network of pathways to which these cells contribute. Although recent trials indicate improved ultrafiltration is achievable with glucose polymer, it is not a biocompatible dialysis fluid in its current manufactured form.