title: Predictive value of urine interleukin-18 in the evolution and outcome of acute kidney injury in critically ill adult patients.
abstract: BACKGROUND
  Interleukin-18 (IL-18) is a pro-inflammatory protein, which mediates ischaemic tubular injury, and has been suggested to be a sensitive and specific biomarker for acute kidney injury (AKI). The predictive value of IL-18 in the diagnosis, evolution, and outcome of AKI in critically ill patients is still unclear.
  
  
  METHODS
  We measured urine IL-18 from critically ill patients at intensive care unit (ICU) admission and 24 h. We evaluated the association of IL-18 with developing new AKI, renal replacement therapy (RRT), and 90-day mortality. We calculated areas under receiver operating characteristics curves (AUCs), best cut-off values, and positive likelihood ratios (LR+) for IL-18 concerning these endpoints. Additionally, we compared the predictive value of IL-18 at ICU admission to that of urine neutrophil gelatinase-associated lipocalin (NGAL).
  
  
  RESULTS
  In this study population of 1439 patients the highest urine IL-18 during the first 24 h in the ICU associated with the development of AKI with an AUC [95% confidence interval (CI)] of 0.586 (0.546-0.627) and with the development of Stage 3 AKI with an AUC (95% CI) of 0.667 (0.591-0.774). IL-18 predicted the initiation of RRT with an AUC (95% CI) of 0.655 (0.572-0.739), and 90-day mortality with an AUC (95% CI) of 0.536 (0.497-0.574).
  
  
  CONCLUSIONS
  IL-18 had poor-to-moderate ability to predict AKI, RRT, or 90-day mortality in this large cohort of critically ill patients. Thus, it should be used with caution for diagnostic or predictive purposes in the critically ill.
authors.affiliation: Intensive Care Units, Division of Anaesthesia and Intensive Care Medicine, Department of Surgery and sara.nisula@hus.fi.
authors.forename: S
authors.initials: S
authors.lastname: Nisula
authors.affiliation: Critical Care Medicine Research Group, Department of Intensive Care Medicine, Tampere University Hospital, Tampere, Finland.
authors.forename: R
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Anaesthesia and Intensive Care Medicine, Lapland Central Hospital, Rovaniemi, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Poukkanen
authors.affiliation: Intensive Care Units, Division of Anaesthesia and Intensive Care Medicine, Department of Surgery and.
authors.forename: S T
authors.initials: ST
authors.lastname: Vaara
authors.affiliation: Intensive Care Units, Division of Anaesthesia and Intensive Care Medicine, Department of Surgery and.
authors.forename: K M
authors.initials: KM
authors.lastname: Kaukonen
authors.affiliation: Department of Anesthesia and Intensive Care Medicine, Turku University Hospital, Turku, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Tallgren
authors.affiliation: Department of Medicine, Division of Nephrology, Helsinki University Central Hospital, Box 340, Helsinki 00029, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Haapio
authors.affiliation: Department of Surgical Sciences/Anaesthesiology and Intensive Care, University of Uppsala, Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Tenhunen
authors.affiliation: Intensive Care Units, Division of Anaesthesia and Intensive Care Medicine, Department of Surgery and.
authors.forename: A M
authors.initials: AM
authors.lastname: Korhonen
authors.affiliation: Intensive Care Units, Division of Anaesthesia and Intensive Care Medicine, Department of Surgery and.
authors.forename: V
authors.initials: V
authors.lastname: Pettilä
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality / Q000628:therapy / Q000652:urine*; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000652:urine; D016638:Critical Illness; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007362:Intensive Care Units; D020382:Interleukin-18 / Q000652:urine*; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D017582:Renal Replacement Therapy / Q000706:statistics & numerical data
chemical_list: D015415:Biomarkers; D020382:Interleukin-18
keywords: acute kidney injury; critical illness; intensive care; interleukin-18; long-term outcome; renal replacement therapy