title: Erythropoiesis-stimulating agent withdrawal and oxidative stress in hemodialysis.
abstract: OBJECTIVE
  Variation of the action of erythropoiesis-stimulating agent (ESA) may modify oxidative stress in hemodialyzed (HD) patients. Our aim was to follow changes of oxidative stress during withdrawal and subsequent resumption of ESA therapy.
  
  
  METHODS
  After a 14-day suspension of epoietin-beta treatment, 11 HD patients received epoietin-beta and 10 patients darbepoietin-alpha. The whole blood oxidized and reduced glutathione (GSSG, GSH) and erythrocyte malondialdehyde (E-MDA) concentrations and the erythrocyte superoxide dismutase (E-SOD) and catalase (E-CAT) activities were determined before the ESA-free interval (baseline) and at Weeks 2, 6, 10 and 14.
  
  
  RESULTS
  In both groups, the ratios GSSG/ GSH were increased at Weeks 2 and 6 (p < 0.001). The E-MDA levels were elevated (p < 0.01) and the E-SOD activities were decreased (p < 0.001) at Week 6. By Week 14, these markers had returned to the baseline, whereas the GSH (p < 0.001) and E-CAT activity levels (p < 0.001) had increased.
  
  
  CONCLUSIONS
  An increase in oxidative stress was revealed by the ratio GSSG/GSH directly after the short-term withdrawal of epoietin-b therapy in HD. This new finding may have implications in conditions involving transiently depressed ESA action. For both ESAs, the early phase of readministration was associated with similarly increased oxidative stress, with a subsequent return to the baseline level.
authors.affiliation: Department of Pediatrics, University of Szeged, Szeged, Hungary. monostoripeter@gmail.com
authors.forename: P
authors.initials: P
authors.lastname: Monostori
authors.forename: Z
authors.initials: Z
authors.lastname: Hracskó
authors.forename: E
authors.initials: E
authors.lastname: Karg
authors.forename: I S
authors.initials: IS
authors.lastname: Varga
authors.forename: Z
authors.initials: Z
authors.lastname: Kiss
authors.forename: T
authors.initials: T
authors.lastname: Boros
authors.forename: E
authors.initials: E
authors.lastname: Kiss
authors.forename: I
authors.initials: I
authors.lastname: Haszon
authors.forename: F
authors.initials: F
authors.lastname: Papp
authors.forename: V
authors.initials: V
authors.lastname: Sümegi
authors.forename: C
authors.initials: C
authors.lastname: Bereczki
authors.forename: S
authors.initials: S
authors.lastname: Túri
mesh_terms: D000740:Anemia / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D000068256:Darbepoetin alfa; D004912:Erythrocytes / Q000201:enzymology; D004921:Erythropoietin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D005500:Follow-Up Studies; D019803:Glutathione Disulfide / Q000097:blood; D006397:Hematinics / Q000494:pharmacology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D011379:Prognosis; D011994:Recombinant Proteins; D006435:Renal Dialysis / Q000379:methods*; D013482:Superoxide Dismutase / Q000097:blood; D028761:Withholding Treatment
chemical_list: D006397:Hematinics; D006454:Hemoglobins; D011994:Recombinant Proteins; C103998:epoetin beta; D004921:Erythropoietin; D000068256:Darbepoetin alfa; D013482:Superoxide Dismutase; D019803:Glutathione Disulfide