title: Measurement of hepcidin isoforms in human serum by liquid chromatography with high resolution mass spectrometry.
abstract: OBJECTIVE
  Hepcidin-25 is the master regulator of iron homeostasis. N-truncated isoforms of hepcidin-25 have been identified (hepcidin-20, -22, -24), although data on the concentrations of these isoforms are sparse.
  
  
  METHODS
  Serum was mixed with aqueous formic acid, and the supernatant loaded onto a 96-well-SPE-plate. Eluted analytes were analyzed using LC-HR-MS. Forty-seven paired dipotassium-EDTA human plasma and serum samples were analyzed.
  
  
  RESULTS
  The LLOQ was 1 μg/l (all analytes). Accuracy and precision were acceptable. There was a good correlation (R2>0.90, all analytes) between matrices. The median (range) serum hepcidin-20, -22, -24 and -25 concentrations measured were 4 (1-40), 8 (2-20), 8 (1-50) and 39 (1-334) μg/l, respectively.
  
  
  CONCLUSIONS
  LC-HR-MS is widely applicable to the measurement of hepcidin-25, and truncated isoforms.
authors.affiliation: Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital, London SE5 9RS, UK.|Diabetes & Nutritional Sciences Division, King's College London, London SE1 9NH, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Handley
authors.affiliation: Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital, London SE5 9RS, UK.
authors.forename: Lewis
authors.initials: L
authors.lastname: Couchman
authors.affiliation: Diabetes & Nutritional Sciences Division, King's College London, London SE1 9NH, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Sharp
authors.affiliation: Department of Renal Medicine, King's College Hospital, London SE5 9RS, UK.
authors.forename: Iain
authors.initials: I
authors.lastname: Macdougall
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital, London SE5 9RS, UK.
authors.forename: Cajetan
authors.initials: C
authors.lastname: Moniz
mesh_terms: D002138:Calibration; D002247:Carbon Isotopes; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D064451:Hepcidins / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D009587:Nitrogen Isotopes; D020033:Protein Isoforms; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D002247:Carbon Isotopes; D064451:Hepcidins; D009587:Nitrogen Isotopes; D020033:Protein Isoforms
keywords: hepcidin-25; isoforms; plasma; serum