LN VITRO BIOCOMPATIBILITY OF A HEAT-STERILIZED, LOW-TOXIC, AND LESS ACIDIC FLUID FOR PERITONEAL-DIALYSIS

Objective: The aim of this study was to investigate a peritoneal dialy sis (PD) fluid (PD-Bio), produced with the intention of reducing the a mount of glucose degradation products and to increase the final pH. Th e heat sterilization of the fluid was performed with the glucose separ ated from the electrolytes. After sterilization the two solutions were combined. Methods: The in vitro biocompatibility of PD-Bio was measur ed as the inhibition of cell growth of a cultured fibroblast cell line and as the stimulated release of interleukin-1 beta from cultured hum an mononuclear cells. The glucose degradation products were measured a s UV absorbance at 228 nm or 284 nm and the concentration of aldehydes was estimated with high-performance liquid chromatography and gas chr omatography. Results: Our results demonstrate that in comparison to co nventional PD fluids the pH of PD-Bio was increased, to about 6.5. Due to less contaminating glucose degradation products in PD-Bio, basal c ytotoxicity was significantly decreased for both 1.5% and 4% glucose-c ontaining fluids, and the stimulated release of interleukin-1 beta was normalized compared to sterile filtered controls with the same pH. UV absorbance measured at 228 nm was decreased, whereas the absorbance a t 284 nm was equal to that of a conventional fluid. In PD-Bio the conc entrations of formaldehyde, acetaldehyde, methylglyoxal, and 2-furalde hyde were found to be below the detection limit, whereas glyoxal was p resent in the same and 5-hydroxymethylfurfural (5-HMF) in higher conce ntrations than in conventionally produced PD fluid. Conclusions: The r esults demonstrate that it is possible to improve biocompatibility of PD fluids by simply changing the way the fluid is produced.