Elevated Urinary IL-18 Levels at the Time of ICU Admission... : Clinical Journal of the American Society of Nephrology (original) (raw)

Original Articles: Original Articles

Elevated Urinary IL-18 Levels at the Time of ICU Admission Predict Adverse Clinical Outcomes

Siew, Edward D.*; Ikizler, T. Alp*; Gebretsadik, Tebeb†; Shintani, Ayumi†; Wickersham, Nancy‡; Bossert, Frederick‡; Peterson, Josh F.§,‖; Parikh, Chirag R.¶; May, Addison K.**; Ware, Lorraine B.‡

Divisions of *Nephrology and

‡Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, and

Departments of **Surgical Critical Care and

†Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee;

§Division of General Internal Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;

‖Geriatric Research Education Clinical Center (GRECC), Tennessee Valley Health System, Veterans Health Administration, Nashville, Tennessee; and

¶Division of Nephrology, Yale University School of Medicine, New Haven, Connecticut

Correspondence: Dr. Lorraine B. Ware, Vanderbilt University Medical Center, 1161 21st Avenue South, Medical Center North/T-1218, Nashville, TN 37232. Phone: 615-322-7872; Fax: 615-343-8780; E-mail: [email protected]

Received December 16, 2009

Accepted April 28, 2010

Abstract

Background and objectives: 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.

Design, setting, participants, & measurements: 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 ≥75 ml/min per 1.73 m2. 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.