title: First Post-Operative Urinary Kidney Injury Biomarkers and Association with the Duration of AKI in the TRIBE-AKI Cohort.
abstract: BACKGROUND
  We previously demonstrated that assessment of the duration of AKI, in addition to magnitude of rise in creatinine alone, adds prognostic information for long-term survival. We evaluated whether post-operative kidney injury biomarkers in urine collected immediately after cardiac surgery associate with duration of serum creatinine elevation.
  
  
  METHODS
  We studied 1199 adults undergoing cardiac surgery in a prospective cohort study (TRIBE-AKI) and examined the association between the levels of five urinary biomarkers individually at 0-6 hours after surgery: interleukin-18 (IL-18), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver fatty acid binding protein (L-FABP) and albumin with duration of serum creatinine-based AKIN criteria for AKI (0 (no AKI), 1-2, 3-6, ≥7 days).
  
  
  RESULTS
  Overall, 407 (34%) patients had at least stage 1 AKI, of whom 251 (61.7%) had duration of 1-2 days, 118 (28.9%) had duration 3-6 days, and 38 (9.3%) had duration of ≥7 days. Higher concentrations of all biomarkers (per log increase) were independently associated with a greater odds of a longer duration of AKI; odds ratios and 95% confidence intervals using ordinal logistic regression were the following: IL-18: 1.22, 1.13-1.32; KIM-1: 1.36, 1.21-1.52; albumin 1.20, 1.09-1.32; L-FABP 1.11, 1.04-1.19; NGAL 1.06, 1.00-1.14). AKI duration of 7 days or longer was associated with a 5-fold adjusted risk of mortality at 3 years.
  
  
  CONCLUSIONS
  There was an independent dose-response association between urinary levels of injury biomarkers immediately after cardiac surgery and longer duration of AKI. Duration of AKI was also associated with long term mortality. Future studies should explore the potential utility of these urinary kidney injury biomarkers to enrich enrollment of patients at risk for longer duration of AKI into trials of interventions to prevent or treat post-operative AKI.
authors.affiliation: Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Coca
authors.affiliation: Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Girish N
authors.initials: GN
authors.lastname: Nadkarni
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.affiliation: Section of Nephrology, Department of Medicine, University of Chicago, Pritzker School of Medicine, Chicago, Illinois, United States of America.
authors.forename: Jay
authors.initials: J
authors.lastname: Koyner
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Heather
authors.initials: H
authors.lastname: Thiessen-Philbrook
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: McArthur
authors.affiliation: Division of General Internal Medicine, San Francisco VA Medical Center, University of California, San Francisco, California, United States of America.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Shlipak
authors.affiliation: Program of Applied Translational Research, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America.
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Parikh
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000652:urine*; D000368:Aged; D000419:Albuminuria / Q000652:urine; D015415:Biomarkers / Q000652:urine; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D003404:Creatinine / Q000097:blood; D050556:Fatty Acid-Binding Proteins / Q000652:urine; D005260:Female; D000072596:Hepatitis A Virus Cellular Receptor 1 / Q000032:analysis; D006801:Humans; D020382:Interleukin-18 / Q000652:urine; D000071068:Lipocalin-2 / Q000652:urine; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers; C493319:FABP1 protein, human; D050556:Fatty Acid-Binding Proteins; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D020382:Interleukin-18; D000071068:Lipocalin-2; D003404:Creatinine