Predictive value of urine interleukin-18 in the evolution and outcome of acute kidney injury in critically ill adult patients.

BACKGROUND: Interleukin-18 (IL-18) is a pro-inflammatory protein, which mediates ischaemic tubular injury, and has been suggested to be a sensitive and specific biomarker for acute kidney injury (AKI). The predictive value of IL-18 in the diagnosis, evolution, and outcome of AKI in critically ill patients is still unclear. METHODS: We measured urine IL-18 from critically ill patients at intensive care unit (ICU) admission and 24 h. We evaluated the association of IL-18 with developing new AKI, renal replacement therapy (RRT), and 90-day mortality. We calculated areas under receiver operating characteristics curves (AUCs), best cut-off values, and positive likelihood ratios (LR+) for IL-18 concerning these endpoints. Additionally, we compared the predictive value of IL-18 at ICU admission to that of urine neutrophil gelatinase-associated lipocalin (NGAL). RESULTS: In this study population of 1439 patients the highest urine IL-18 during the first 24 h in the ICU associated with the development of AKI with an AUC [95% confidence interval (CI)] of 0.586 (0.546-0.627) and with the development of Stage 3 AKI with an AUC (95% CI) of 0.667 (0.591-0.774). IL-18 predicted the initiation of RRT with an AUC (95% CI) of 0.655 (0.572-0.739), and 90-day mortality with an AUC (95% CI) of 0.536 (0.497-0.574). CONCLUSIONS: IL-18 had poor-to-moderate ability to predict AKI, RRT, or 90-day mortality in this large cohort of critically ill patients. Thus, it should be used with caution for diagnostic or predictive purposes in the critically ill.

Acute kidney injury in patients with severe sepsis in Finnish Intensive Care Units.

BACKGROUND: Severe sepsis is one of the leading causes of acute kidney injury (AKI). Patients with sepsis-associated AKI demonstrate high-hospital mortality. We evaluated the incidence of severe sepsis-associated AKI and its association with outcome in intensive care units (ICUs) in Finland. METHODS: This was a predetermined sub-study of the prospective, observational, multicentre FINNAKI study conducted in 17 ICUs during 1 September 2011 and 1 February 2012. All emergency ICU admissions and elective admissions exceeding 24 hours in the ICU were screened for presence of severe sepsis and AKI up to 5 days in ICU. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria and severe sepsis according to the American College of Chest Physicians/Society of Critical Care Medicine (ACCP/SCCM) criteria. RESULTS: Of the 2901 included patients, severe sepsis was diagnosed in 918 (31.6%, 95% confidence interval [CI] 29.9-33.4%) patients. Of these 918 patients, 488 (53.2% [95% CI 49.9-56.5%]) had AKI. The 90-day mortality rate was 38.1% (95% CI 33.7-42.5%) for severe sepsis patients with AKI and 24.7% (95% CI 20.5-28.8%) for those without AKI. After adjusting for covariates, KDIGO stage 3 AKI was associated with an increased risk for 90-day mortality with an adjusted odds ratio (OR) of 1.94 (95% CI 1.28-2.94), but stages 1 and 2 were not. CONCLUSIONS: More than half of the patients with severe sepsis had AKI according to the KDIGO classification, and AKI stage 3 was independently associated with 90-day mortality.