Elevated urinary IL-18 levels at the time of ICU admission predict adverse clinical outcomes.
OBJECTIVE
Urine IL-18 (uIL-18) has demonstrated moderate capacity to predict acute kidney injury (AKI) and adverse outcomes in defined settings. Its ability to predict AKI and provide prognostic information in broadly selected, critically ill adults remains unknown.


METHODS
The study prospectively evaluated the capacity of uIL-18 measured within 24 hours of intensive care unit (ICU) admission to predict AKI, death, and receipt of acute dialysis in a large mixed-adult ICU population.


RESULTS
Of 451 patients, 86 developed AKI within 48 hours of enrollment and had higher median uIL-18 levels [426 (interquartile range [IQR]: 152 to 1183) pg/mg creatinine] compared with those without AKI [248 (IQR: 120 to 559) pg/mg]. The area under the receiver operating characteristic curve for uIL-18 predicting subsequent AKI within 24 hours was 0.62 (95% CI: 0.54 to 0.69) and improved modestly to 0.67 (95% CI: 0.53 to 0.81) in patients whose enrollment eGFR was >or=75 ml/min per 1.73 m(2). The highest median uIL-18 levels were observed in patients with sepsis at enrollment [508 (IQR: 230 to 1281) pg/mg], those receiving acute dialysis [571 (IQR: 161 to 1614) pg/mg] or dying [532 (IQR: 210 to 1614) pg/mg] within 28 days of ascertainment. After adjustment for a priori selected clinical predictors, uIL-18 remained independently predictive of composite outcome of death or acute dialysis within 28 days of ascertainment (odds ratio, 1.86 [95% CI: 1.31 to 2.64]).


CONCLUSIONS
uIL-18 did not reliably predict AKI development, but did predict poor clinical outcomes in a broadly selected, critically ill adult population.
Siew
Edward D
ED
Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Ikizler
T Alp
TA
Gebretsadik
Tebeb
T
Shintani
Ayumi
A
Wickersham
Nancy
N
Bossert
Frederick
F
Peterson
Josh F
JF
Parikh
Chirag R
CR
May
Addison K
AK
Ware
Lorraine B
LB
D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy / Q000652:urine; D000209:Acute-Phase Proteins / Q000652:urine; D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016009:Chi-Square Distribution; D003404:Creatinine / Q000097:blood; D016638:Critical Illness; D003956:Dialysis; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007362:Intensive Care Units; D020382:Interleukin-18 / Q000652:urine*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010343:Patient Admission; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000652:urine; D018570:Risk Assessment; D012307:Risk Factors; D013714:Tennessee; D013997:Time Factors; D015854:Up-Regulation
D000209:Acute-Phase Proteins; D015415:Biomarkers; D020382:Interleukin-18; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine