title: Hepcidin-25 vs. conventional clinical biomarkers in the diagnosis of functional iron deficiency.
abstract: OBJECTIVE
  As hepcidin-25 is considered as a key regulator of human iron homoeostasis, this study aimed to compare this parameter with conventional biomarkers and diagnostic tools of iron deficiency (ID).
  
  
  METHODS
  In total, 233 hospitalised adult patients, who underwent routine blood testing for ID, were included. All subjects were investigated for hepcidin-25, reticulocyte haemoglobin content (CHr), soluble transferrin receptor (sTfR)/log ferritin ratio (i.e. Thomas plot), sTfR, ferritin, transferrin saturation (TSAT), C-reactive protein (CRP) and for complete blood cell count. Functional ID was defined as a CHr < 28 pg. Separate logistic regression models were calculated with all potential biomarkers to evaluate and compare the predictive performance with respect to functional ID in patients without (CRP ≤ 0.5 mg/dL) and with (CRP > 0.5 mg/dL) acute-phase reaction, respectively.
  
  
  RESULTS
  One hundred seventeen patients with CRP > 0.5 mg/dL showed a distinctly higher hepcidin-25 median value [35.60 (range: 4.27-80.03) ng/mL] as compared to 116 patients with CRP ≤ 0.5 mg/dL [18.55 (range: 3.77-73.01) ng/mL]. With respect to functional ID, sTfR/log ferritin ratio and sTfR were of better positive predictive value (PPV) (sTfR/log ferritin ratio: 58.33% and 70.83%; sTfR: 60.00% and 60.00%) than when compared to hepcidin-25 (PPV: 37.74% and 42.86%) and ferritin (PPV: 27.54% and 46.15%) in both subgroups.
  
  
  CONCLUSIONS
  The sTfR/log ferritin ratio, as well as sTfR, were better predictors of functional ID in patients with and without acute-phase reaction as compared to hepcidin-25 and ferritin.
authors.affiliation: Institute of Laboratory Medicine, General Hospital Steyr, Steyr, Austria.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Enko
authors.affiliation: Department of Applied Statistics, Johannes Kepler University Linz, Linz, Austria.
authors.forename: Helga
authors.initials: H
authors.lastname: Wagner
authors.affiliation: Institute of Laboratory Medicine, General Hospital Steyr, Steyr, Austria.
authors.forename: Gernot
authors.initials: G
authors.lastname: Kriegshäuser
authors.affiliation: Institute of Laboratory Medicine, General Hospital Steyr, Steyr, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Kimbacher
authors.affiliation: Institute of Laboratory Medicine, General Hospital Steyr, Steyr, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Stolba
authors.affiliation: Institute of Laboratory Medicine, General Hospital Steyr, Steyr, Austria.
authors.forename: Elfriede
authors.initials: E
authors.lastname: Worf
authors.affiliation: Institute of Laboratory Medicine, General Hospital Steyr, Steyr, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Halwachs-Baumann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000175:diagnosis / Q000378:metabolism; D015415:Biomarkers; D004909:Erythrocyte Indices; D005260:Female; D064451:Hepcidins / Q000097:blood*; D006760:Hospitalization; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D017701:Reticulocyte Count; D055815:Young Adult
chemical_list: D015415:Biomarkers; D064451:Hepcidins; C545475:hepcidin 25, human; D007501:Iron
keywords: diagnostic implication; functional iron deficiency; hepcidin-25