title: Plasma neutrophil gelatinase-associated lipocalin is associated with iron status in anemic patients with pre-dialysis chronic kidney disease.
abstract: BACKGROUND
  Iron deficiency anemia is common in patients with chronic kidney disease (CKD). Neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of acute kidney injury, is known to be associated with iron metabolism. We investigated whether plasma NGAL level is associated with iron status in pre-dialysis CKD patients with anemia.
  
  
  METHODS
  This study included 419 patients who had anemia. The subjects were into categorized into a pre-dialysis group (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m2, n = 288) and a non-CKD group (eGFR >60 ml/min/1.73 m2, n = 131). The associations between plasma NGAL and iron status (serum ferritin and transferrin saturation [TSAT]), eGFR, albumin, uric acid, total cholesterol, calcium, phosphate, and C-reactive protein (CRP) were assessed.
  
  
  RESULTS
  In non-CKD group, plasma NGAL was not associated with any baseline variables including iron indices (TSAT and serum ferritin). In pre-dialysis group, univariate analysis showed plasma NGAL correlated with eGFR, CRP, TSAT, and serum ferritin. In multivariate analysis, plasma NGAL was independently associated with TSAT. However, serum ferritin lost its association with plasma NGAL. In ROC analysis for identifying iron deficiency, the plasma NGAL (best cut-off value ≤394 ng/ml) was superior to the serum ferritin (suggested cut-off value ≤500 ng/ml) in both sensitivity and specificity.
  
  
  CONCLUSIONS
  Plasma NGAL is associated with iron status in anemic patients with pre-dialysis CKD. Further studies are needed to demonstrate the role of plasma NGAL in assessing the iron deficiency and in guiding the iron therapy for pre-dialysis CKD patients.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea.
authors.forename: Il Young
authors.initials: IY
authors.lastname: Kim
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea.
authors.forename: Joo Hui
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea.
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea. sbleemd@pusan.ac.kr.|Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea. sbleemd@pusan.ac.kr.
authors.forename: Soo Bong
authors.initials: SB
authors.lastname: Lee
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Medical Research Institute, Pusan National University Hospital, Busan, South Korea.
authors.forename: Harin
authors.initials: H
authors.lastname: Rhee
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Medical Research Institute, Pusan National University Hospital, Busan, South Korea.
authors.forename: Sang Heon
authors.initials: SH
authors.lastname: Song
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Medical Research Institute, Pusan National University Hospital, Busan, South Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Seong
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, 20, Geumo-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do, 50612, South Korea.|Medical Research Institute, Pusan National University Hospital, Busan, South Korea.
authors.forename: Ihm Soo
authors.initials: IS
authors.lastname: Kwak
mesh_terms: D000328:Adult; D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005293:Ferritins / Q000032:analysis; D005919:Glomerular Filtration Rate; D006801:Humans; D007501:Iron / Q000097:blood*; D000071068:Lipocalin-2 / Q000097:blood*; D054834:Lipocalins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D011237:Predictive Value of Tests; D012372:ROC Curve; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000097:blood*; D014168:Transferrin / Q000032:analysis
chemical_list: D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D014168:Transferrin; D005293:Ferritins; D007501:Iron
keywords: Anemia; Chronic kidney disease; Iron deficiency; Neutrophil gelatinase-associated lipocalin