title: Comparison of Two Methods for Determination of NGAL Levels in Urine: ELISA and CMIA.
abstract: BACKGROUND
  Neutrophil gelatinase-associated lipocalin (NGAL) is a new useful biomarker for the early diagnosis of acute kidney injury. The aim of the study was to compare two analytical methods for measurement of urinary NGAL: enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA).
  
  
  METHODS
  Two assays were used to measure urinary NGAL: ELISA kit (R&D Systems) and ARCHITECT Urine NGAL (Abbott Laboratories). The study material was the urine obtained from 30 healthy subjects (mean age 56.4 ± 15.2).
  
  
  RESULTS
  The median value and interquantile range of urinary NGAL in the studied group measured by ELISA (R&D Systems) were 3.5 ng/ml (1.2; 6.6) and by CMIA (ARCHITECT Urine NGAL assay, Abbott Diagnostics) were 4.4 ng/ml (1.9; 9.4). Levels of urinary NGAL obtained by CMIA were significantly higher than by ELISA. There was a significant positive correlation between the concentration of urinary NGAL determined by both methods (r = 0.8625, P < 0.01).
  
  
  CONCLUSIONS
  The comparison of individual data obtained by ELISA and CMIA should be taken with care. From laboratory's point of view, ELISA is less expensive than CMIA method for the determination of NGAL in urine. However, CMIA method allows rapid determination of urinary NGAL concentration through automated assay.
authors.affiliation: Department of Immunology, Transplantology and Internal Diseases, Transplantation Institute, Medical University of Warsaw, Warsaw, Poland.|Department of Bioanalysis and Drugs Analysis, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland.
authors.forename: E
authors.initials: E
authors.lastname: Krzeminska
authors.affiliation: Department of Immunology, Transplantology and Internal Diseases, Transplantation Institute, Medical University of Warsaw, Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Wyczalkowska-Tomasik
authors.affiliation: Department of Immunology, Transplantology and Internal Diseases, Transplantation Institute, Medical University of Warsaw, Warsaw, Poland.|Department of Bioanalysis and Drugs Analysis, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland.
authors.forename: N
authors.initials: N
authors.lastname: Korytowska
authors.affiliation: Department of Immunology, Transplantology and Internal Diseases, Transplantation Institute, Medical University of Warsaw, Warsaw, Poland. leszek.paczek@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Paczek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D000071068:Lipocalin-2 / Q000652:urine*; D008163:Luminescent Measurements / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: C489506:LCN2 protein, human; D000071068:Lipocalin-2
keywords: acute kidney injury; biomarker; immunoassay; lipocalin-2; neutrophil gelatinase-associated lipocalin; renal diseases