In spite of its benefits, many peritoneal dialysis patients ultimately have to switch dialysis therapy to hemodialysis secondary to technique failure. Numerous etiologies for peritoneal dialysis treatment failure exist and include the continuous exposure of the peritoneal membrane to bioincompatible dialysis solutions with acidic pH and high content of glucose degradation products. These factors have been implicated in mesothelial cell loss, fibrosis and neovascularization, resulting in alterations in solute transport and ultrafiltration failure. Novel peritoneal dialysis solutions with neutral pH and low concentrations of glucose degradation products have recently been developed to improve biocompatibility and ameliorate the consequences of membrane damage with conventional peritoneal dialysis solutions. While novel peritoneal dialysis solutions have been available outside the United States for several years, Delflex Neutral pH has only recently been approved for use in the United States. Thus, the majority of all the data supporting the benefits of these novel solutions comes from locations outside of the United States.

The central question regarding the novel peritoneal dialysis solution is whether long term use will result in better preservation of the peritoneal membrane to support dialysis. Ultimately, this can only be determined with studies comparing long term outcomes of patients using the various solutions. However, given the expected availability in the United States and the potential benefits of the novel peritoneal dialysis solutions long term studies comparing outcomes with conventional solutions raises ethical concerns. Therefore, surrogate markers for peritoneal membrane integrity are necessary. Short term studies using various surrogate markers to assess mesothelial cell mass and peritoneal inflammation such as Cancer Antigen 125 (CA125) and pro-inflammatory cytokines have been reported, but it is uncertain how well these markers predict long term outcome. Recently, a novel approach to predict outcome has been reported, using mesothelial cell shedding and apoptosis. The number of mesothelial cells and the number of apoptotic mesothelial cells in a standard 8 hour dialysis dwell were reported to correlate well with deterioration of peritoneal dialysis characteristics over a one year follow-up. The authors concluded that mesothelial cell shedding and apoptosis are reliable predictors of peritoneal membrane deterioration.

The purpose of this study is to evaluate the impact of Delflex neutral pH (a biocompatible peritoneal dialysis solution) on mesothelial cell viability and peritoneal transport. The study will specifically compare mesothelial cell shedding and apoptosis in the peritoneal dialysis effluent after exposure to Delflex neutral pH solution and conventional peritoneal dialysis solution. Cancer Antigen 125 (CA125)levels (indicative of mesothelial cell mass) and connective tissue growth factor (CTGF) levels (a marker of inflammation) will be measured in the spent dialysate to determine whether these markers correlate with cell shedding and apoptosis. The study will also characterize the transport of glucose degradation products (GDPs) and advanced glycosylation end products (AGEs) across the mesothelial cells after exposure to Delflex neutral pH solution versus conventional peritoneal dialysis solution.