The Role of Dialysis Membranes on Intradialytic Selenium Removal and on Selenium Status in Patients Receiving Renal Replacement Therapy

Background/Aims: Dialysis membrane has been implicated in selenium (Se) deficiency in hemodialysis (HD). Intradialytic Se removal into dialysate through different membranes was investigated. Methods: We studied 19 patients on standard HD with low-flux polysulfone membrane (group A), 10 patients on standard HD with ethylene vinyl alcohol membrane (group B), 12 patients on hemodiafiltration (HDF; group C) and 16 healthy subjects (control group D). Se was measured in blood before and after dialysis session and in effluent dialysate every hour during session. Results: In all patients together, pre-dialysis serum Se levels were lower than those in control group, but, in a separate analysis, only in standard HD. In all patient groups, there was a net Se removal into dialysate but it was greater in HDF patients who, however, had similar pre-dialysis serum Se levels to those in healthy controls. Conclusion: An intradialytic Se loss was found with all 3 membrane types, but it is not the principal factor for Se depletion in HD.