title: Serum hepcidin-25 may replace the ferritin index in the Thomas plot in assessing iron status in anemic patients.
abstract: BACKGROUND
  Biochemical markers of iron deficiency do not distinguish iron-deficient anemia (IDA) from the anemia of chronic disease (ACD) and the combined state of ACD/IDA. Serum hepcidin-25 might be a marker resolving this problem. We investigated the extent to which serum hepcidin-25 enables the differentiation of the states above in comparison with the ferritin index plot, the so-called Thomas plot [soluble transferrin receptor (sTfR)/log ferritin and the reticulocyte hemoglobin content (CHr)].
  
  
  METHODS
  Serum hepcidin-25 was determined in 155 anemic patients who were classified as having latent iron deficiency (latent ID), IDA, ACD, or ACD/IDA using the ferritin index plot (Thomas plot). Hepcidin-25 was determined using an isotope-dilution micro-HPLC-tandem mass spectrometry method. The ability to discriminate among these states based on serum hepcidin-25 alone or in combination with the CHr was evaluated in a receiver operating characteristic curve analysis and a comparison with the recently established ferritin index plot.
  
  
  RESULTS
  Serum hepcidin-25 correlated with ferritin and the ferritin index. Use of a hepcidin-25 cutoff level of ≤4 nmol/l allowed the differentiation of IDA from ACD and ACD/IDA. Furthermore, the discrimination of ACD/IDA from ACD required combination with CHr in a new plot (hepcidin-25 and the CHr). The hepcidin-25 plot and the ferritin index plot showed a good correspondence in the differentiation of iron states in patients with anemia.
  
  
  CONCLUSIONS
  Patients with IDA can be differentiated from ACD and ACD/IDA but not ACD from ACD/IDA based on hepcidin-25 alone. The combination of hepcidin-25 with CHr in the hepcidin-25 plot was useful for the differentiation of the states above.
authors.affiliation: Department of Urology, University Hospital, Mainz, Germany. th-books@t-online.de
authors.forename: C
authors.initials: C
authors.lastname: Thomas
authors.forename: U
authors.initials: U
authors.lastname: Kobold
authors.forename: S
authors.initials: S
authors.lastname: Balan
authors.forename: R
authors.initials: R
authors.lastname: Roeddiger
authors.forename: L
authors.initials: L
authors.lastname: Thomas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000175:diagnosis*; D023181:Antimicrobial Cationic Peptides / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D005293:Ferritins / Q000097:blood*; D064451:Hepcidins; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D008875:Middle Aged
chemical_list: D023181:Antimicrobial Cationic Peptides; D015415:Biomarkers; D064451:Hepcidins; C545475:hepcidin 25, human; D005293:Ferritins; D007501:Iron