title: Hemodiafiltration with post-dilution reinfusion of the regenerated ultrafiltrate: a new on-line technique.
abstract: OBJECTIVE
  All convective hemodiafiltration techniques require a replacement fluid, which must have an adequate electrolytic composition and must be sterile and pyrogen-free. Using an integrated adsorption cartridge, the ultrafiltrate can be "regenerated" and used as a replacement fluid (hemo-filtrate reinfusion; HFR). The aim of this study was to evaluate whether the HFR technique as suggested in its original configuration could be improved by inverting the purification sequence (post-dilution HFR; PDHFR) in order to increase the purification efficiency of the whole system.
  
  
  METHODS
  We performed standard HFR in 6 uremic patients during 6 months and, subsequently, during further 6 months, PDHFR. The dialytic efficacy of the two techniques and the filter blood loss were evaluated. Moreover, we studied how both techniques affected cytokine levels.
  
  
  RESULTS
  We observed a significant increase of urea extraction and of Kt/V values in PDHFR. An equally significant improvement was observed in regard to the extraction of beta2-m and the blood loss. Furthermore, IL6 and TNFalpha decreased significantly after PDHFR treatment.
  
  
  CONCLUSIONS
  HFR has proven to be an easy-to-perform hemodiafiltration technique, capable of resolving the typical problem of the other hemodiafiltration technique, the availability and production of a sterile and ultrapure reinfusion solution. The inversion of its configuration has allowed us to improve three aspects that have characterized, in our experience, the treatments performed in the original geometry: the removal of both urea and beta2-m, and the filter. Finally, it's notable that the decrease in cytokines levels achieved with PDHFR might attenuate the uremic micro-inflammatory state.
authors.affiliation: Nephrology and Dialysis Unit, St. Eugenio Hospital, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Meloni
authors.forename: P M
authors.initials: PM
authors.lastname: Ghezzi
authors.forename: S
authors.initials: S
authors.lastname: Cipriani
authors.forename: S
authors.initials: S
authors.lastname: Petroni
authors.forename: C
authors.initials: C
authors.lastname: Tozzo
authors.forename: P
authors.initials: P
authors.lastname: Tatangelo
authors.forename: B
authors.initials: B
authors.lastname: Rossini
authors.forename: V
authors.initials: V
authors.lastname: Rossi
authors.forename: A
authors.initials: A
authors.lastname: Cecilia
authors.forename: C U
authors.initials: CU
authors.lastname: Casciani
mesh_terms: D000328:Adult; D000368:Aged; D016207:Cytokines / Q000097:blood; D005260:Female; D017583:Hemodiafiltration / Q000379:methods*; D015312:Hemodialysis Solutions / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014508:Urea / Q000097:blood; D014511:Uremia / Q000097:blood / Q000628:therapy*; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D016207:Cytokines; D015312:Hemodialysis Solutions; D001613:beta 2-Microglobulin; D014508:Urea