Open AccessUrine IL-18 Is an Early Diagnostic Marker for Acute Kidney Injury and Predicts Mortality in the Intensive Care Unit
Author(s) -
Chirag R. Parikh,
Edward Abraham,
Marek Ancukiewicz,
Charles L. Edelstein
Publication year - 2005
Publication title -
journal of the american society of nephrology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.451
H-Index - 279
eISSN - 1533-3450
pISSN - 1046-6673
DOI - 10.1681/asn.2005030236
Subject(s) - medicine , acute kidney injury , creatinine , urine , odds ratio , renal function , ards , intensive care unit , urinary system , receiver operating characteristic , kidney disease , urology , confidence interval , sepsis , gastroenterology , lung
Serum creatinine is not an ideal marker of renal function in patients with acute kidney injury (AKI). Previous studies demonstrated that urinary IL-18 is increased in human AKI. Thus, whether urine IL-18 is an early diagnostic marker of AKI was investigated. A nested case-control study was performed within the Acute Respiratory Distress Syndrome (ARDS) Network trial. AKI was defined as an increase in serum creatinine by at least 50% within the first 6 d of ARDS study enrollment. A total of 400 urine specimens that were collected on study days 0, 1, and 3 of the ARDS trial were available from 52 case patients and 86 control patients. The data were analyzed in a cross-sectional manner and according to the time before development of AKI. The median urine IL-18 levels were significantly different at 24 and 48 h before AKI in case patients as compared with control patients. On multivariable analysis, urine IL-18 values predicted development of AKI 24 and 48 h later after adjustment for demographics, sepsis, Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) III score, serum creatinine, and urine output. Urine IL-18 levels of >100 pg/ml are associated with increased odds of AKI of 6.5 (95% confidence interval 2.1 to 20.4) in the next 24 h. On diagnostic performance testing, urine IL-18 demonstrates an area under the receiver operating characteristic curve of 73% to predict AKI in the next 24 h. The urine IL-18 values were also significantly different between survivors and nonsurvivors (P < 0.05), and on multivariable analysis, the urine IL-18 value on day 0 is an independent predictor of mortality. Urinary IL-18 levels can be used for the early diagnosis of AKI. Urine IL-18 levels also predict the mortality of patients who have ARDS and are in the intensive care unit.