title: Intra-individual variability of serum hepcidin-25 in haemodialysis patients using mass spectrometry and ELISA.
abstract: BACKGROUND
  Measurement of serum hepcidin levels may provide a useful alternative to the current methods of determining iron status in chronic haemodialysis (HD) patients. However, the biological variability of this pivotal regulator of iron homeostasis is unclear, and the impact of inflammation, dialysis clearance and iron therapy on hepcidin variability has not been established.
  
  
  METHODS
  Two independent studies in chronic HD patients were conducted; serum hepcidin levels were measured at the start of dialysis sessions in 20 UK patients and in 43 Dutch patients by mass spectrometry (MS). Samples from UK patients were also analysed by a competitive enzyme-linked immunosorbent assay (cELISA). Coefficient of variance (CV(1)) was calculated and potential factors affecting CV(1) were also examined.
  
  
  RESULTS
  The median CV(1) (inter-quartile range) was 23% (17-28) for the UK MS, 26% (17-48) for the Dutch MS and 23% (17-39) for the UK cELISA. The CV(1) was similar in those patients receiving and those not receiving regular intravenous iron. The CV(1) was not associated with the degree of inflammation. Hepcidin levels were higher following an inter-dialytic period of 3 versus 2 days (P = 0.02).
  
  
  CONCLUSIONS
  These findings suggest considerable variability of serum hepcidin levels in HD patients. Inflammation and the use of iron did not impact on the degree of variability, and hepcidin levels were higher after an inter-dialytic period of 3 versus 2 days. These findings need to be taken into account in future studies assessing the utility of serum hepcidin as a guide to the use of iron or erythropoiesis-stimulating agents therapy.
authors: Department of Nephrology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. h.peters@nier.umcn.nl
authors: Hilde P E
authors: HP
authors: Peters
authors: Adam
authors: A
authors: Rumjon
authors: Sukhvinder S
authors: SS
authors: Bansal
authors: Coby M M
authors: CM
authors: Laarakkers
authors: Jan A J G
authors: JA
authors: van den Brand
authors: Pantelis
authors: P
authors: Sarafidis
authors: Rebecca
authors: R
authors: Musto
authors: Jolanta
authors: J
authors: Malyszko
authors: Dorine W
authors: DW
authors: Swinkels
authors: Jack F M
authors: JF
authors: Wetzels
authors: Iain C
authors: IC
authors: Macdougall
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000740:Anemia / Q000097:blood / Q000209:etiology / Q000628:therapy; D023181:Antimicrobial Cationic Peptides / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D064451:Hepcidins; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D007501:Iron / Q000008:administration & dosage / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D009426:Netherlands; D006435:Renal Dialysis / Q000009:adverse effects*; D006113:United Kingdom; D055815:Young Adult
chemical_list: D023181:Antimicrobial Cationic Peptides; D015415:Biomarkers; D064451:Hepcidins; D018836:Inflammation Mediators; C545475:hepcidin 25, human; D002097:C-Reactive Protein; D007501:Iron