title: Effect of synthetic vitamin E-bonded membrane on responsiveness to erythropoiesis-stimulating agents in hemodialysis patients: a pilot study.
abstract: BACKGROUND
  Oxidative stress, a recently identified factor related to the response to erythropoiesis-stimulating agents (ESAs), is increased in hemodialysis patients. The aim of this study was to verify whether ESA responsiveness improves if the anti-oxidant vitamin E (Vi-E) is placed on the blood-side layer of a synthetic polysulfone (PS) dialyzer.
  
  
  METHODS
  This 8-month, controlled and open randomized study involved 2 groups of patients on stable ESA therapy undergoing hemodialysis using a PS dialyzer with or without Vi-E treatment. Hemoglobin, albumin, high-sensitivity C-reactive protein, interleukin-6, iron status, parathyroid hormone (PTH), Vi-E (alpha- and gamma-tocopherol levels) and the oxidative stress markers, advanced oxidation protein products, carbonyls and advanced glycation end products were evaluated every 2 months. The primary outcome measure was ESA resistance, the weekly ESA dose divided by the product between hemoglobin level and end-dialysis body weight.
  
  
  RESULTS
  Nineteen of the 20 randomized patients completed the study. During the follow-up, the ESA resistance significantly decreased (p = 0.024), greater in the Vi-E group (37%) than in the PS group (20%), but this difference was not statistically significant (p = 0.596). Baseline PTH and Vi-E levels were associated with ESA resistance. In the secondary analysis, including these covariates in the model, the difference between groups in ESA resistance became significant (p = 0.042).
  
  
  CONCLUSIONS
  Vi-E placed on the blood-side of a dialyzer may have a possible beneficial effect on ESA resistance in hemodialysis patients; baseline PTH levels seem to predict ESA resistance and were useful in showing the possible beneficial effect of Vi-E and should be considered in designing adequate-sized trials for testing this hypothesis.
authors.affiliation: Department of Nephrology, Dialysis and Renal Transplantation, A. Manzoni Hospital, Lecco, Italy.
authors.forename: Simeone
authors.initials: S
authors.lastname: Andrulli
authors.forename: Salvatore
authors.initials: S
authors.lastname: Di Filippo
authors.forename: Celestina
authors.initials: C
authors.lastname: Manzoni
authors.forename: Luca
authors.initials: L
authors.lastname: Stefanelli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Floridi
authors.forename: Francesco
authors.initials: F
authors.lastname: Galli
authors.forename: Francesco
authors.initials: F
authors.lastname: Locatelli
mesh_terms: D000368:Aged; D000740:Anemia / Q000209:etiology* / Q000517:prevention & control*; D000975:Antioxidants / Q000008:administration & dosage; D004359:Drug Therapy, Combination; D005260:Female; D006397:Hematinics / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D006435:Renal Dialysis / Q000009:adverse effects*; D016896:Treatment Outcome; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D006397:Hematinics; D014810:Vitamin E