Early prediction of urinary tract infection with urinary neutrophil gelatinase associated lipocalin.
Neutrophil gelatinase associated lipocalin (NGAL) is a protein identified in human neutrophil granules. The aim of the study was to assess whether urine level of NGAL (uNGAL) could represent a novel, reliable marker of urinary tract infection (UTI) and to determine the optimal cutoff level for uNGAL to predict UTI in children. Sixty patients with symptomatic UTI and 29 healthy controls were enrolled the study. Urine NGAL was measured by enzyme-linked immunosorbent assay. A dimercaptosuccinic acid (DMSA) radionuclide scan was performed within 7 days in the patients with UTI in an attempt to distinguish pyelonephritis from cystitis. Mean uNGAL level was significantly higher in the UTI group than in the controls (91.02 ng/ml vs 14.29 ng/ml, p = 0.0001) and using a cutoff 20 ng/ml for uNGAL for diagnosis of UTI, sensitivity, and specificity were 97% and 76%, respectively [area under the curve (AUC): 0.979]. Mean uNGAL/creatinine ratio (uNGAL/Cr) was also significantly higher in the UTI group [201.81 ng/mg creatinine (Cr) vs 18.08 ng/mg Cr; p = 0.0001], and using a cutoff 30 ng/mg Cr for uNGAL/Cr for diagnosis of UTI, sensitivity and specificity were 98% and 76%, respectively (AUC: 0.992). In conclusion, both uNGAL and uNGAL/Cr can be used as a novel, sensitive marker for early prediction of UTI in the absence of acute kidney injury and chronic kidney disease, and the optimal cutoff value for prediction of UTI is lower than the values determined for acute kidney injury. Further investigations with larger patient groups are required to confirm our results.
Yilmaz
Alev
A
Pediatric Nephrology, Bakirkoy Maternity and Childrens Hospital, Bogazkoy Kardelen Villalari No: 26 Bahcesehir, Istanbul, Turkey. alevyy@yahoo.com
Sevketoglu
Esra
E
Gedikbasi
Asuman
A
Karyagar
Savas
S
Kiyak
Aysel
A
Mulazimoglu
Mehmet
M
Aydogan
Gonul
G
Ozpacaci
Tevfik
T
Hatipoglu
Sami
S
D000209:Acute-Phase Proteins / Q000652:urine*; D019540:Area Under Curve; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006090:Gram-Negative Bacteria / Q000145:classification / Q000302:isolation & purification; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D015337:Multicenter Studies as Topic; D009504:Neutrophils / Q000737:chemistry*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013997:Time Factors; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000382:microbiology
D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine