Phenotyping of Acute Kidney Injury: Beyond Serum Creatinine

Semin Nephrol. 2018 Jan;38(1):3-11. doi: 10.1016/j.semnephrol.2017.09.002.


Acute kidney injury (AKI) is a common complication in hospitalized patients and is associated with adverse short- and long-term outcomes. AKI is diagnosed by serum creatinine (SCr)-based consensus definitions that capture an abrupt decrease in glomerular filtration rate associated with AKI. However, SCr-based AKI definitions lack sensitivity and specificity for diagnosing structural kidney injury. Moreover, AKI is a heterogeneous condition consisting of distinct phenotypes based on its etiology, prognosis, and molecular pathways, and that may potentially require different therapies. SCr-based AKI definitions provide no information on these AKI phenotypes. This review highlights traditional and novel tools that overcome the limitations of SCr-based AKI definitions to improve AKI phenotyping.

Keywords: AKI; IL-18; IL-6; KIM-1; L-FABP; NGAL; biomarkers; creatinine; cystatin C; furosemide; urinary casts; urine microscopy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Acute Kidney Injury / blood*
  • Acute Kidney Injury / diagnosis
  • Acute Kidney Injury / physiopathology
  • Biomarkers
  • Creatinine / blood*
  • Glomerular Filtration Rate
  • Hemodynamics
  • Humans
  • Kidney Tubules / physiopathology
  • Phenotype
  • Prognosis


  • Biomarkers
  • Creatinine