title: In vivo removal of high- and low-molecular-weight compounds in hemodiafiltration with on-line regeneration of ultrafiltrate.
abstract: BACKGROUND
  Current methods of renal replacement therapy, combining convection and diffusion, are largely unsatisfactory in removing uremic toxins. Adsorption is a third mechanism that has been applied in extracorporeal therapy. This study evaluates the impact of hemodiafiltration with on-line regeneration of ultrafiltrate, a new two-step integrated sorbent system, on in vivo removal of a wide spectrum of solutes with different molecular weights.
  
  
  METHODS
  Pre- and post-dialysis concentrations of small, medium-size, and large molecules were determined in ten patients undergoing regular hemodiafiltration treatments with on-line regeneration of the ultrafiltrate. We also analyzed, at different times of the same dialysis session, the inlet and outlet ultrafiltrate; the latter had been regenerated by the sorbent cartridge and was used as reinfusion liquid. The mean dialysis time was 260 +/- 21.2 min with a blood flow of 361 +/- 33.3 ml/min and a reinjection volume of 3.6 +/- 0.2 l/h.
  
  
  RESULTS
  Urea, creatinine and phosphate reduction ratio were respectively 69.8 +/- 8.2, 61.9 +/- 5.5, and 40.2 +/- 17.3%. Removal of medium-size markers such as calcitonin, osteocalcin, beta2-microglobulin, cystatin C, myoglobin and prolactin varied between 24 and 60%. The percentage of reduction for retinol binding protein and alpha1-microglobulin was negligible and we were unable to demonstrate any removal of alpha1-acid glycoprotein, pre-albumin, and albumin in the regenerated ultrafiltrate.
  
  
  CONCLUSIONS
  The hemodiafiltration with on-line regeneration of ultrafiltrate is a new hemodialysis system, which allows uremic toxin removal over a wide molecular-weight spectrum.
authors.affiliation: E.C.H.O., Expansion Centres de Hémodialyse de l'Ouest, Nantes, France. atesta@echo-sante.com
authors.forename: Angelo
authors.initials: A
authors.lastname: Testa
authors.forename: Hervé
authors.initials: H
authors.lastname: Gentilhomme
authors.forename: Didier
authors.initials: D
authors.lastname: Le Carrer
authors.forename: Jean Luc
authors.initials: JL
authors.lastname: Orsonneau
mesh_terms: D000368:Aged; D003404:Creatinine / Q000097:blood*; D015314:Dialysis Solutions / Q000493:pharmacokinetics; D005260:Female; D017583:Hemodiafiltration / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D010455:Peptides / Q000097:blood; D010710:Phosphates / Q000097:blood*; D011506:Proteins / Q000032:analysis; D012709:Serum Albumin / Q000032:analysis; D014508:Urea / Q000097:blood*; D014511:Uremia / Q000097:blood* / Q000517:prevention & control
chemical_list: D015314:Dialysis Solutions; D010455:Peptides; D010710:Phosphates; D011506:Proteins; D012709:Serum Albumin; D014508:Urea; D003404:Creatinine