title: Neutrophil gelatinase-associated lipocalin and end-stage renal disease: it is not all about the kidneys!
abstract: BACKGROUND
  Neutrophil gelatinase-associated lipocalin (NGAL) is a powerful biomarker for the early detection of acute kidney injury. However, recent data suggest that NGAL also plays an important role in chronic kidney disease (CKD), reflecting the level of acute kidney damage within the CKD condition. To study whether elevated NGAL levels in CKD are a consequence of damaged tubular cells or rather due to extrarenal production, we investigated NGAL levels in anephric patients on dialysis.
  
  
  METHODS
  Plasma NGAL levels were investigated in 14 dialysis patients who underwent bilateral nephrectomy (anephric group), 18 anuric dialysis patients with remaining kidneys (dialysis group) and 12 healthy patients (healthy group).
  
  
  RESULTS
  Plasma NGAL levels were significantly lower in the healthy group compared with the anephric group (143 vs. 981 ng/mL; P < 0·001) or the dialysis group (143 vs. 838 ng/mL; P < 0·001), respectively. However, NGAL levels did not differ between the anephric group and the dialysis group (981 vs. 838 ng/mL; P = 0·19).
  
  
  CONCLUSIONS
  Assuming that NGAL is highly expressed in chronically damaged kidneys due to tubular stress, there should be significantly less NGAL in anephric patients compared with anuric dialysis patients with remaining kidneys. In contrast to this hypothesis, we found no difference in NGAL expression between these two groups, proving the entire extrarenal NGAL production in anephric patients and suggesting that the tubular NGAL expression seems to be negligible in anuric dialysis patients.
authors.affiliation: Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany. Simon.Rau@med.uni-muenchen.de
authors.forename: Simon
authors.initials: S
authors.lastname: Rau
authors.forename: Antje
authors.initials: A
authors.lastname: Habicht
authors.forename: Teresa
authors.initials: T
authors.lastname: Kauke
authors.forename: Andreas
authors.initials: A
authors.lastname: Hillmer
authors.forename: Matthias
authors.initials: M
authors.lastname: Wessely
authors.forename: Manfred
authors.initials: M
authors.lastname: Stangl
authors.forename: Markus
authors.initials: M
authors.lastname: Guba
authors.forename: Michael
authors.initials: M
authors.lastname: Fischereder
authors.forename: Ulf
authors.initials: U
authors.lastname: Schönermarck
mesh_terms: D000209:Acute-Phase Proteins; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003404:Creatinine / Q000378:metabolism; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood*; D009392:Nephrectomy / Q000379:methods; D009393:Nephritis / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000097:blood*; D006435:Renal Dialysis; D012189:Retrospective Studies
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine
keywords: End-stage renal disease; haemodialysis; nephrectomy; neutrophil gelatinase-associated lipocalin