Peritoneal dialysis, membranes and beyond

PURPOSE OF REVIEW: The peritoneal membrane provides the interface between dialysate fluid and blood for peritoneal dialysis patients. Functional properties of the peritoneal membrane have important clinical implications. This review will outline recent observations concerning structural changes in the peritoneal membrane and the impact on function and clinical outcomes. RECENT FINDINGS: Peritoneal membrane function - solute transport and ultrafiltration - is a complex process involving new blood vessel growth along with changes in the nature of blood vessels and the interstitial environment of these vessels. Advanced glycation end-products produced by reactive oxygen species in the dialysis fluid have been identified as an agent of tissue fibrosis. Nitric oxide and IL-6 also have important roles in peritoneal membrane injury. Gene polymorphisms associated with peritoneal membrane function have been identified. As the mechanisms of peritoneal membrane injury become better elucidated, targeted therapies are being developed. The role of biocompatible and nonglucose dialysis fluids needs to be further defined. SUMMARY: The peritoneal membrane is the lifeline for peritoneal dialysis patients. Our understanding of mechanisms of injury and functional responses continues to expand and will hopefully lead to therapies to improve the clinical outcomes for peritoneal dialysis patients.