title: Novel biomarkers for early diagnosis of acute kidney injury.
abstract: BACKGROUND
  Acute kidney injury (AKI) is a common and serious problem in critically ill patients. Tests currently used to detect AKI (i.e., serum creatinine, serum urea and various urinary indices) often result in serious delays in detection of clinically relevant injury. This delayed detection translates into a potential missed opportunity for therapeutic interventions at a time when kidney damage may be limitable or reversible. This is also recognized as a potential reason for the poor clinical outcomes often associated with AKI.
  
  
  OBJECTIVE
  To appraise the recent literature characterizing several novel serum and urinary biomarkers, including neutrophil gelatinase-associated lipocalin, IL-18 and kidney injury molecule-1, which are capable of detecting AKI at an earlier phase of injury. Also to discuss the pitfalls of current conventional testing in kidney injury.
  
  
  METHODS
  Narrative literature review.
  
  
  CONCLUSIONS
  These novel biomarkers can detect injury when damage may still be reversible, allow for early risk stratification and/or prognostication, and are associated in early clinical studies with important outcomes such as severity of AKI, need for renal replacement therapy and survival. There is optimism that these novel biomarkers will discriminate the underlying pathophysiology of AKI (i.e., ischemia, sepsis, toxins or multifactorial), discriminate AKI from other renal disease (i.e., chronic kidney disease) and aid in localizing the site of acute injury in the kidney. As such, the future may entail development of an 'AKI biomarker panel' (i.e., analogous to a cardiac or liver enzyme panel) for use in clinical practice.
authors.affiliation: University of Alberta Hospital, 3C1.12 Walter C. Mackenzie Centre, Division of Critical Care Medicine, 8440-112 Street, Edmonton, Alberta, T6G2B7, Canada +1 780 407 6755 ; +1 780 407 1228 ; bagshaw@ualberta.ca.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw