title: Serum interleukin-18 at commencement of renal replacement therapy predicts short-term prognosis in critically ill patients with acute kidney injury.
abstract: BACKGROUND
  Acute kidney injury (AKI) requiring renal replacement therapy (RRT) in critically ill patients results in a high hospital mortality. Outcome prediction in this selected high-risk collective is challenging due to the lack of appropriate biomarkers. The aim of this study was to identify outcome-specific biomarkers in this patient population.
  
  
  RESULTS
  Serum samples were collected from 101 critically ill patients with AKI at the initiation of RRT in intensive care units (ICUs) of a tertiary care university hospital between August 2008 and March 2011. Measurements of serum levels of cystatin C (CysC), neutrophil gelatinase-associated lipocalin, and interleukin-18 (IL-18) were performed. The primary outcome measure was hospital mortality. The observed overall mortality rate was 56.4% (57/101). Multiple logistic regression analysis indicated that the serum IL-18 and CysC concentrations and Acute Physiology and Chronic Health Evaluation III (ACPACHE III) scores determined on the first day of RRT were independent predictors of hospital mortality. The APACHE III score had the best discriminatory power (0.872 ± 0.041, p<0.001), whereas serum IL-18 had the best Youden index (0.65) and the highest correctness of prediction (83%). Cumulative survival rates at 6-month follow-up following hospital discharge differed significantly (p<0.001) for serum IL-18 <1786 pg/ml vs. ≥ 1786 pg/ml in these critically ill patients.
  
  
  CONCLUSIONS
  In this study, we confirmed the grave prognosis for critically ill patients at the commencement of RRT and found a strong correlation between serum IL-18 and the hospital mortality of ICU patients with dialysis-dependent AKI. In addition, we demonstrated that the APACHE III score has the best discriminative power for predicting hospital mortality in these critically ill patients.
authors.affiliation: Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan.
authors.forename: Chan-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Chih-Hsiang
authors.initials: CH
authors.lastname: Chang
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Fan
authors.forename: Ya-Chung
authors.initials: YC
authors.lastname: Tian
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: Chang
authors.forename: Chang-Chyi
authors.initials: CC
authors.lastname: Jenq
authors.forename: Cheng-Chieh
authors.initials: CC
authors.lastname: Hung
authors.forename: Ji-Tseng
authors.initials: JT
authors.lastname: Fang
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Yang
authors.forename: Yung-Chang
authors.initials: YC
authors.lastname: Chen
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D000209:Acute-Phase Proteins; D016638:Critical Illness; D055316:Cystatin C / Q000097:blood; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D020382:Interleukin-18 / Q000097:blood*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000097:blood; D017582:Renal Replacement Therapy
chemical_list: D000209:Acute-Phase Proteins; D055316:Cystatin C; D020382:Interleukin-18; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins