Clinical Study Urine β-2-Microglobulin, Osteopontin, and Trefoil Factor 3 May Early Predict Acute Kidney Injury and Outcome after Cardiac Arrest Sigrid Beitland , 1,2 Espen Rostrup Nakstad, 3 Jens Petter Berg, 1,4 Anne-Marie Siebke Trøseid, 4 Berit Sletbakk Brusletto, 4 Cathrine Brunborg, 5 Christofer Lundqvist, 1,6 and Kjetil Sunde 1,2 1 Institute of Clinical Medicine, University of Oslo, P.O.Box 1072 Blindern, 0316 Oslo, Norway 2 Department of Anaesthesiology, Oslo University Hospital, P.O.Box 4950 Nydalen, 0424 Oslo, Norway 3 Norwegian National Unit for CBRNE Medicine, Oslo University Hospital, P.O.Box 4956 Nydalen, 0424 Oslo, Norway 4 Department of Medical Biochemistry, Oslo University Hospital, P.O.Box 4950 Nydalen, 0424 Oslo, Norway 5 Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, P.O.Box 1122 Blindern, 0317 Oslo, Norway 6 Health Services Research Unit and Department of Neurology, Akershus University Hospital, P.O.Box 1000, 1478 Lørenskog, Norway Correspondence should be addressed to Sigrid Beitland; sigrid.beitland@medisin.uio.no Received 2 November 2018; Accepted 9 April 2019; Published 7 May 2019 Academic Editor: omas J. Esposito Copyright © 2019 Sigrid Beitland et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. Acute kidney injury (AKI) is a common complication after out-of-hospital cardiac arrest (OHCA), leading to increased mortality and challenging prognostication. Our aim was to examine if urine biomarkers could early predict postarrest AKI and patient outcome. Methods. A prospective observational study of resuscitated, comatose OHCA patients admitted to Oslo University Hospital in Norway. Urine samples were collected at admission and day three postarrest and analysed for β-2- microglobulin (β2M), osteopontin, and trefoil factor 3 (TFF3). Outcome variables were AKI within three days according to the Kidney Disease Improving Global Outcome criteria, in addition to six-month mortality and poor neurological outcome (PNO) (cerebral performance category 3–5). Results. Among 195 included patients (85% males, mean age 60 years), 88 (45%) developed AKI, 88 (45%) died, and 96 (49%) had PNO. In univariate analyses, increased urine β2M, osteopontin, and TFF3 levels sampled at admission and day three were independent risk factors for AKI, mortality, and PNO. Exceptions were that β2M measured at day three did not predict any of the outcomes, and TFF3 at admission did not predict AKI. In multivariate analyses, combining clinical parameters and biomarker levels, the area under the receiver operating characteristics curves (95% CI) were 0.729 (0.658–0.800), 0.797 (0.733–0.861), and 0.812 (CI 0.750–0.874) for AKI, mortality, and PNO, respectively. Conclusions. Urine levels of β2M, osteopontin, and TFF3 at admission and day three were associated with increased risk for AKI, mortality, and PNO in comatose OHCA patients. is trail is registered with NCT01239420. 1. Introduction Acute kidney injury (AKI) affects around 37% of initial cardiac arrest (CA) survivors; the condition is associated with increased morbidity and mortality [1, 2]. Uniform definitions of AKI based on serum creatinine and urine output are useful in clinical practice and research, for in- stance the Kidney Disease Improving Global Outcomes (KDIGO) criteria [3]. However, a major shortcoming of these definitions is that AKI is detected quite late, and early Hindawi Critical Care Research and Practice Volume 2019, Article ID 4384796, 9 pages https://doi.org/10.1155/2019/4384796