title: Reassessment of Iron Biomarkers for Prediction of Dialysis Iron Overload: An MRI Study.
abstract: OBJECTIVE
  Iron overload among hemodialysis patients was previously considered rare but is now an increasingly recognized clinical situation. We analyzed correlations between iron biomarkers and the liver iron concentration (LIC) measured by magnetic resonance imaging (MRI), and examined their diagnostic accuracy for iron overload.
  
  
  METHODS
  We performed a prospective cross-sectional study from 31 January 2005 to 31 August 2013 in the dialysis centre of a French community-based private hospital. A cohort of 212 hemodialysis patients free of overt inflammation or malnutrition, were treated for anemia with parenteral iron-sucrose and an erythropoesis-stimulating agent, in keeping with current clinical guidelines. Blinded measurements of hepatic iron stores were performed by T1 and T2* contrast MRI, and relationships were analysed using Spearman's coefficient, logistic regression and receiver-operator characteristic (ROC) curves.
  
  
  RESULTS
  Among the biological markers, only serum ferritin showed a strong correlation with LIC (rho= 0.52, 95% CI: 0.41-0.61, p< 0.0001, Spearman test). In logistic analysis, only serum ferritin correctly classified the overall cohort into patients with normal liver iron stores (LIC ≤ 50 μmol/g) and those with elevated liver iron stores (LIC > 50 μmol/g) (odds ratio 1.007; 95% CI: 1.004-1.010). Serum ferritin was the iron biomarker with the best discriminatory capacity in ROC curves analysis (area under the curve (AUC) = 0.767; 95% CI: 0.698-0.835). The optimal serum ferritin cutoffs were 160 μg/L for LIC > 50 μmol/g (mild iron overload) and 290 μg/L for LIC > 200 μmol/g (severe iron overload).
  
  
  CONCLUSIONS
  For clinical purposes, serum ferritin correctly reflects liver iron stores, as assessed by MRI, in hemodialysis patients without overt inflammation or malnutrition. These results strongly suggest that current ferritin target values should be lowered to avoid iron overload.
  
  
  BACKGROUND
  ISRCTN Registry 80100088.
authors.affiliation: Division of Nephrology and Dialysis, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Rostoker
authors.affiliation: Division of Nephrology and Dialysis, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Griuncelli
authors.affiliation: Division of Nephrology and Dialysis, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Loridon
authors.affiliation: Division of Nephrology and Dialysis, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Théophile
authors.initials: T
authors.lastname: Magna
authors.affiliation: Department of Biochemistry, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Machado
authors.affiliation: Division of Radiology, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Drahi
authors.affiliation: Division of Radiology, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Dahan
authors.affiliation: Division of Radiology, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Janklewicz
authors.affiliation: Division of Radiology, Ramsay Générale de Santé, Hôpital Privé Claude Galien, Quincy sous Sénart, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Cohen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007501:Iron / Q000378:metabolism; D019190:Iron Overload / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008099:Liver / Q000378:metabolism; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D006435:Renal Dialysis / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005293:Ferritins; D007501:Iron