Urinary biomarkers in the early diagnosis of acute kidney injury

Kidney Int. 2008 Apr;73(7):863-9. doi: 10.1038/sj.ki.5002715. Epub 2007 Dec 5.


A change in the serum creatinine is not sensitive for an early diagnosis of acute kidney injury. We evaluated urinary levels of matrix metalloproteinase-9 (MMP-9), N-acetyl-beta-D-glucosaminidase (NAG), and kidney injury molecule-1 (KIM-1) as biomarkers for the detection of acute kidney injury. Urine samples were collected from 44 patients with various acute and chronic kidney diseases, and from 30 normal subjects in a cross-sectional study. A case-control study of children undergoing cardio-pulmonary bypass surgery included urine specimens from each of 20 patients without and with acute kidney injury. Injury was defined as a greater than 50% increase in the serum creatinine within the first 48 h after surgery. The biomarkers were normalized to the urinary creatinine concentration at 12, 24, and 36 h after surgery with the areas under the receiver-operating characteristic curve compared for performance. In the cross-sectional study, the area under the curve for MMP-9 was least sensitive followed by KIM-1 and NAG. Combining all three biomarkers achieved a perfect score diagnosing acute kidney injury. In the case-control study, KIM-1 was better than NAG at all time points, but combining both was no better than KIM-1 alone. Urinary MMP-9 was not a sensitive marker in the case-control study. Our results suggest that urinary biomarkers allow diagnosis of acute kidney injury earlier than a rise in serum creatinine.

Publication types

  • Research Support, N.I.H., Extramural
  • Comment

MeSH terms

  • Acetylglucosaminidase / urine*
  • Acute Kidney Injury / urine*
  • Adult
  • Aged
  • Biomarkers / urine
  • Case-Control Studies
  • Cross-Sectional Studies
  • Early Diagnosis
  • Female
  • Hepatitis A Virus Cellular Receptor 1
  • Humans
  • Male
  • Matrix Metalloproteinase 9 / urine*
  • Membrane Glycoproteins / urine*
  • Middle Aged
  • Prospective Studies
  • Receptors, Virus


  • Biomarkers
  • HAVCR1 protein, human
  • Hepatitis A Virus Cellular Receptor 1
  • Membrane Glycoproteins
  • Receptors, Virus
  • Acetylglucosaminidase
  • Matrix Metalloproteinase 9