Role of HFR Cartridge in the Removal of Mediators of Inflammation and P-cresol in Hemodialysis Patients

A major limitation of standard hemodialysis is that it does not clear the plasma from interleukin-6 (IL-6) and p-cresol, two uremic toxins responsible for the high cardiovascular risk in end stage renal disease (ESRD). In the present study, we evaluated whether these compounds are removed by HFR-Supra, a double-chamber hemodiafiltration system in which the ultrafiltrate (UF) returns to the patient after its regeneration through a resin cartridge. We selected 8 inflamed chronic hemodialysis (HD) patients, which underwent a single 240 minutes HFR session. We studied the change in both IL-6 and p-cresol circulating levels, by comparing pre- and post-HFR serum concentrations. In addition, we compared Il-6 and p-cresol levels in the UF entering (UFin) and exiting (UFout) from the cartridge, either at the start or at the end of the HFR session. The proinflammatory activity of UFin and UFout was determined by evaluating the changes that they induced in IL-6 messenger ribonucleic acid (mRNA) expression and release in peripheral blood mononuclear cells (PBMC) collected from 8 healthy volunteers and cultured in vitro for 24 hr.