title: Differentiation of acute pyelonephritis from other febrile states in children using urinary neutrophil gelatinase-associated lipocalin (uNGAL).
abstract: BACKGROUND
  Acute pyelonephritis is a severe disease which is sometimes difficult to recognize based on clinical symptoms and routinely available diagnostic tests, especially in young children. The aim of this study was to assess the diagnostic value of urinary neutrophil gelatinase-associated lipocalin (uNGAL) as a biomarker of acute pyelonephritis.
  
  
  METHODS
  In this case-control study we analyzed 134 children (median age 2.5 years) who were admitted to the Pediatric Clinic of University Hospital Centre Osijek, Croatia. Eighty of them had acute pyelonephritis, while 54 children had febrile state of different etiology including cystitis and they represented the control group. uNGAL, white blood cells, C-reactive protein, urinanalysis, urine culture, kidney ultrasound and a dimercaptosuccinic acid scintigraphic scan were done for each child. uNGAL was measured using chemiluminiscent microparticle immunoassay on ARHITECT i1000SR (Abbott Diagnostics, IL, USA).
  
  
  RESULTS
  uNGAL values were significantly higher in children with acute pyelonephritis compared to the control groups (113.6 ng/mL vs. 10.2 ng/mL, p<0.001). A receiver operating characteristic curve comparison was done for tested parameters and encouraging results were obtained for uNGAL (AUC=0.952). A cut-off value of 29.4 ng/mL had 92.5% sensitivity and 90.7% specificity. We showed that uNGAL can also serve in differentiating acute pyelonephritis from cystitis (cut-off 38.5 ng/mL), and for differentiation of cystitis from febrile states with etiology other than urinary tract infection (UTI) (cut-off 20.4 ng/mL).
  
  
  CONCLUSIONS
  uNGAL can be a useful diagnostic biomarker in acute pyelonephritis in children, but also in differentiating cystitis from febrile states other than UTI.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Arambašić
authors.forename: Sanja
authors.initials: S
authors.lastname: Mandić
authors.forename: Željko
authors.initials: Ž
authors.lastname: Debeljak
authors.forename: Dario
authors.initials: D
authors.lastname: Mandić
authors.forename: Vesna
authors.initials: V
authors.lastname: Horvat
authors.forename: Vatroslav
authors.initials: V
authors.lastname: Šerić
mesh_terms: D000208:Acute Disease; D000209:Acute-Phase Proteins / Q000652:urine*; D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003556:Cystitis / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D005334:Fever / Q000652:urine*; D006801:Humans; D007223:Infant; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D011518:Proto-Oncogene Proteins / Q000652:urine*; D011704:Pyelonephritis / Q000175:diagnosis* / Q000652:urine*; D014552:Urinary Tract Infections / Q000175:diagnosis
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins