Cross-Membrane Flux Is a Major Factor Influencing Dialysis Patient Outcomes

Abstract

Conventional diffusive-based dialysis modalities including high-flux hemodialysis are limited in their capacity to clear middle and large size uremic toxins. Middle molecule substances are recognized as pathogenic substances implicated in the genesis of accelerated atherosclerosis. Convective methods, mimicking glomeruli filtration of native kidneys, are required to enlarge the molecular weight spectrum of solutes removed. By combining diffusive and convective solute clearances, HDF offers at the present time the highest dialysis efficiency method with the more biocompatible profile. Instantaneous dialyzer clearance does not reflect solute mass removal when body clearance is concerned. Intracorporeal resistance to solute clearance is the main barrier to solute removal. Increasing treatment time and/or frequency of sessions in hemodiafiltration is the only way to overcome body barriers generated from patient/dialysis interaction. A dialysis dose based on normalized middle molecules clearance using Beta2-microglobulin as surrogate marker should be considered as a new adequacy target.

Hemodiafiltration with Endogenous Reinfusion with and without Acetate-Free Dialysis Solutions: Effect on ESA Requirement

“…Subsequently, numerous literature reports have confirmed the erythropoiesis-stimulating effects produced through the use of methods implying a large convective component [2,3,4,5,6,7,8,9,10,11,12,13]. …”

Monocyte and Neutrophil Chemotactic Activity at the Site of Interstitial Inflammation in Patients on High-Flux Hemodialysis or Hemodiafiltration

“…Some of the toxic uremic retention solutes have effects on leukocyte chemotaxis, activation of monocytes and macrophages and release of cytokines, contributing to the state of low-grade inflammation and priming of leukocytes in uremia [19][20][21] , together with a state of oxidative stress [22] . There is an effective clearance of phosphate, leptin, p-cresol and other compounds with HDF methods, and all these have important effects on the inflammatory response and oxidative stress [23] . Also, clearance of cytokines by highflux dialysis treatment has recently gained intense interest, especially in patients with septicemia [24] .…”

“…Also, clearance of cytokines by highflux dialysis treatment has recently gained intense interest, especially in patients with septicemia [24] . HDF and high-flux HD have been associated with better outcomes in large studies [23] and also cause less oxidative stress than HD with low-flux polysulfone membranes [25] . The in vivo data in the present study are in line with our previously reported data on the impact of dialysis membrane permeability on neutrophil transmigration properties in vitro.…”

Leukocyte Function in High-Flux Hemodialysis

“…In a Cochrane database review by Rabindranath et al in 2006, the authors were unable to demonstrate a significant advantage with convective therapies over low-flux hemodialysis with regard to clinical outcomes such as mortality, dialysis-related hypotension and hospitalization (Rabindranath et al 2006). The DOPPS study (Dialysis Outcomes and Practice Patterns Study) revealed that patients on high-flux hemodiafiltration had a 35 % lower mortality rate than patients on low-flux hemodialysis (Canaud et al 2006;Canaud et al 2008). …”