title: Urinary interleukin 18 for detection of acute kidney injury: a meta-analysis.
abstract: BACKGROUND
  Interleukin 18 (IL-18) has been proposed as a biomarker for the early detection of acute kidney injury (AKI), but a broad range of its predictive accuracy has been reported.
  
  
  METHODS
  Meta-analysis of diagnostic test studies.
  
  
  METHODS
  Various clinical settings of AKI, including after cardiac surgery, after contrast infusion, in the emergency department, or in the intensive care unit.
  
  
  METHODS
  Prospective studies that investigated the diagnostic accuracy of IL-18 level to predict AKI.
  
  
  METHODS
  Increasing or increased urinary IL-18 excretion.
  
  
  METHODS
  The primary outcome was AKI development, mainly based on serum creatinine level (definition varied across studies). The other outcome was in-hospital mortality.
  
  
  RESULTS
  We analyzed data from 23 studies and 7 countries involving 4,512 patients. Of these studies, 18 could be included in the meta-analysis. Across all settings, the diagnostic odds ratio (DOR) for urinary IL-18 level to predict AKI was 4.22 (95% CI, 2.90-6.14), with sensitivity and specificity of 0.58 and 0.75, respectively. The area under the receiver operating characteristic curve (AUROC) of urinary IL-18 level to predict AKI was 0.70 (95% CI, 0.66-0.74). Subgroup analysis showed the DOR/AUROC of urinary IL-18 was 5.32 (95% CI, 2.92-9.70)/0.72 (95% CI, 0.68-0.76) in cardiac surgery patients and 3.65 (95% CI, 1.88-7.10)/0.66 (95% CI, 0.62-0.70) in intensive care unit or coronary care unit patients. After stratification for age, IL-18 level had better diagnostic accuracy in children and adolescents versus adults: 8.12 (95% CI, 3.79-17.41)/0.78 (95% CI, 0.75-0.82) versus 3.31 (95% CI, 2.28-4.80)/0.66 (95% CI, 0.62-0.70). There was no significant difference in predictive performance of urinary IL-18 level among various times.
  
  
  CONCLUSIONS
  Various clinical settings; different definition of AKI and serum creatinine level as the reference standard test for the diagnosis of AKI.
  
  
  CONCLUSIONS
  Urinary IL-18 is a useful biomarker of AKI with moderate predictive value across all clinical settings.
authors.affiliation: Division of Nephrology, Nephrology Institute of PLA, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Liu
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Guo
authors.forename: Jiayou
authors.initials: J
authors.lastname: Zhang
authors.forename: Chenggang
authors.initials: C
authors.lastname: Xu
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Yu
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Mao
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Ye
authors.forename: Changlin
authors.initials: C
authors.lastname: Mei
authors.forename: Bing
authors.initials: B
authors.lastname: Dai
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000401:mortality / Q000652:urine*; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000652:urine*; D002648:Child; D003325:Coronary Care Units; D003404:Creatinine / Q000097:blood; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D020382:Interleukin-18 / Q000652:urine*; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve
chemical_list: D015415:Biomarkers; D020382:Interleukin-18; D003404:Creatinine
keywords: Interleukin 18; acute kidney injury; meta-analysis; review