title: Serum copper and ferroportin in monocytes of hemodialysis patients are both decreased but unassociated.
abstract: OBJECTIVE
  Disturbed iron homeostasis contributes to resistance to recombinant human erythropoietin (rHuEpo) in hemodialysis (HD) patients. Although increased hepcidin, which downregulates the iron exporter ferroportin, had been incriminated, such an association has not been confirmed. Albeit not universally accepted, it has been supported that in case of copper deficiency, decreased activity of multicopper oxidases induces endocytosis and degradation of ferroportin. Ferroportin in monocytes, serum copper, ceruloplasmin and markers of iron status were measured, and associations with rHuEpo resistance index (ERI) were evaluated.
  
  
  METHODS
  After a 4-week washout period from iron treatment, 34 HD patients and 20 healthy volunteers enrolled in the study. Ferroportin was assessed by means of Western blotting, copper colorimetrically, whereas ceruloplasmin with enzyme-linked immunosorbent assay. Hemoglobin, serum iron, ferritin and transferrin saturation (TSAT) were also measured.
  
  
  RESULTS
  Ferroportin in monocytes of HD patients was decreased. Serum copper, ceruloplasmin, iron and TSAT were decreased. No correlation between copper or ceruloplasmin and ferroportin was detected. ERI was negatively correlated with ferroportin and all the markers of iron adequacy, but not with copper or ceruloplasmin.
  
  
  CONCLUSIONS
  Although copper deficiency and decreased ferroportin are common in HD patients, copper might not play role in ferroportin level in monocytes and in iron metabolism in this population.
authors.affiliation: Department of Nephrology, Medical School, University of Thessaly, Neo Ktirio, Mezourlo Hill, 411 10, Larissa, Greece, teleftheriadis@yahoo.com.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Eleftheriadis
authors.forename: Georgios
authors.initials: G
authors.lastname: Pissas
authors.forename: Georgia
authors.initials: G
authors.lastname: Antoniadi
authors.forename: Georgios
authors.initials: G
authors.lastname: Filippidis
authors.forename: Spyridon
authors.initials: S
authors.lastname: Golfinopoulos
authors.forename: Aginor
authors.initials: A
authors.lastname: Spanoulis
authors.forename: Vassilios
authors.initials: V
authors.lastname: Liakopoulos
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stefanidis
mesh_terms: D027682:Cation Transport Proteins / Q000032:analysis*; D002570:Ceruloplasmin / Q000032:analysis; D003300:Copper / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000737:chemistry*; D006435:Renal Dialysis; D000098742:Ferroportin
chemical_list: D027682:Cation Transport Proteins; D000098742:Ferroportin; D003300:Copper; D002570:Ceruloplasmin