title: Ferroportin in monocytes of hemodialysis patients and its associations with hepcidin, inflammation, markers of iron status and resistance to erythropoietin.
abstract: OBJECTIVE
  Disturbed iron homeostasis contributes to resistance to recombinant human erythropoietin (rHuEpo) in hemodialysis (HD) patients. Increased hepcidin, which downregulates the iron exporter ferroportin, has been incriminated. However, other factors also control ferroportin expression in mononuclear phagocyte system. Ferroportin in monocytes, as well as serum hepcidin, interleukin-6 (IL-6) and common markers of iron status were measured and correlations 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, whereas hepcidin and IL-6 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 hepcidin and IL-6 were increased, whereas serum iron and TSAT were decreased. ERI was negatively correlated with ferroportin and all the markers of iron adequacy, but not with hepcidin.
  
  
  CONCLUSIONS
  Decreased ferroportin in monocytes of HD patients accompanies increased hepcidin, inflammation, decreased iron availability and is correlated with resistance to rHuEpo treatment.
authors.affiliation: Department of Nephrology, Medical School, University of Thessaly, Neo Ktirio, Mezourlo Hill, 41110, 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: Maria
authors.initials: M
authors.lastname: Remoundou
authors.forename: Georgios
authors.initials: G
authors.lastname: Filippidis
authors.forename: Georgia
authors.initials: G
authors.lastname: Antoniadi
authors.forename: Niki
authors.initials: N
authors.lastname: Oustampasidou
authors.forename: Vassilios
authors.initials: V
authors.lastname: Liakopoulos
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stefanidis
mesh_terms: D000368:Aged; D000740:Anemia / Q000188:drug therapy* / Q000209:etiology; D016022:Case-Control Studies; D027682:Cation Transport Proteins / Q000378:metabolism*; D000068256:Darbepoetin alfa; D004351:Drug Resistance; D004921:Erythropoietin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005293:Ferritins / Q000097:blood; D006397:Hematinics / Q000627:therapeutic use*; D006454:Hemoglobins / Q000378:metabolism; D064451:Hepcidins / Q000097:blood; D006801:Humans; D007249:Inflammation / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007501:Iron / Q000097:blood; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D006435:Renal Dialysis / Q000009:adverse effects; D000098742:Ferroportin
chemical_list: D027682:Cation Transport Proteins; D006397:Hematinics; D006454:Hemoglobins; D064451:Hepcidins; D015850:Interleukin-6; C508420:continuous erythropoietin receptor activator; D000098742:Ferroportin; D004921:Erythropoietin; D000068256:Darbepoetin alfa; D011092:Polyethylene Glycols; D005293:Ferritins; D007501:Iron