The endothelial surface layer: a new target of research in kidney failure and peritoneal dialysis

The endothelial glycocalyx is an important regulator of vascular homeostasis, and damage to this complex structure results in increased vascular vulnerability. Together with associated plasma molecules it forms the endothelial surface layer. Because of its vasculoprotective effects, the endothelial glycocalyx is highly relevant in the context of high vascular risk conditions such as chronic kidney failure. Patients with end-stage renal disease have endothelial dysfunction and are at high risk to develop cardiovascular disease. This thesis reports investigations aimed at defining the state of the endothelial glycocalyx in chronic kidney failure. More specifically, in part I, we investigate the state of the endothelial surface layer in patients with end-stage renal disease, treated with hemodialysis or peritoneal dialysis, and after successful kidney transplantation. In addition, we address the utility of plasma concentrations of hyaluronan and hyaluronidase activity as potential markers for endothelial glycocalyx damage in this group of patients. In part II, we focus on the role of the endothelial surface layer in peritoneal dialysis. For this, we assess the sublingual and peritoneal microvascular endothelial glycocalyx, and investigate the relationships with peritoneal transport. In part III, we describe the peritoneal alterations induced by long-term exposure to dialysis solutions with high glucose concentration in an experimental model of chronic kidney disease.