{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T12:52:47Z","timestamp":1783947167770,"version":"3.55.0"},"reference-count":28,"publisher":"Oxford University Press (OUP)","issue":"2","license":[{"start":{"date-parts":[[2021,5,24]],"date-time":"2021-05-24T00:00:00Z","timestamp":1621814400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2021,5,24]],"date-time":"2021-05-24T00:00:00Z","timestamp":1621814400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100003042","name":"Else Kr\u00f6ner-Fresenius-Stiftung","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100003042","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100005971","name":"Deutsche Herzstiftung","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100005971","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Universit\u00e4tsklinikum Magdeburg"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Nephrol"],"published-print":{"date-parts":[[2022,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Acute kidney injury (AKI) subtypes combining kidney functional parameters and injury biomarkers may have prognostic value. We aimed to determine whether neutrophil gelatinase-associated lipocalin (NGAL)\/hepcidin-25 ratio (urinary concentrations of NGAL divided by that of hepcidin-25) defined subtypes are of prognostic relevance in cardiac surgery patients.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We studied 198 higher-risk cardiac surgery patients. We allocated patients to four groups: Kidney Disease Improving Global Outcomes (KDIGO)-AKI-negative and NGAL\/hepcidin-25 ratio-negative (no AKI), KDIGO AKI-negative and NGAL\/hepcidin-25 ratio-positive (subclinical AKI), KDIGO AKI-positive and NGAL\/hepcidin-25 ratio-negative (clinical AKI), KDIGO AKI-positive and NGAL\/hepcidin-25 ratio-positive (combined AKI). Outcomes included in-hospital mortality (primary) and long-term mortality (secondary).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We identified 127 (61.6%) patients with no AKI, 13 (6.6%) with subclinical, 40 (20.2%) with clinical and 18 (9.1%) with combined AKI. Subclinical AKI patients had a 23-fold greater in-hospital mortality than no AKI patients. For combined AKI vs. no AKI or clinical AKI, findings were stronger (odds ratios (ORs): 126 and 39, respectively). After adjusting for EuroScore, volume of intraoperative packed red blood cells, and aortic cross-clamp time, subclinical and combined AKI remained associated with greater in-hospital mortality than no AKI and clinical AKI (adjusted ORs: 28.118, 95% CI 1.465\u2013539.703; 3.737, 95% CI 1.746\u20137.998). Cox proportional hazard models found a significant association of biomarker-informed AKI subtypes with long-term survival compared with no AKI (adjusted ORs: pooled subclinical and clinical AKI: 1.885, 95% CI 1.003\u20133.542; combined AKI: 1.792, 95% CI 1.367\u20132.350).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In the presence or absence of KDIGO clinical criteria for AKI, the urinary NGAL\/hepcidin-25-ratio appears to detect prognostically relevant AKI subtypes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>\n                      NCT00672334, clinicaltrials.gov, date of registration: 6th May 2008,\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/clinicaltrials.gov\/ct2\/show\/NCT00672334\">https:\/\/clinicaltrials.gov\/ct2\/show\/NCT00672334<\/jats:ext-link>\n                      .\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Graphic abstract<\/jats:title>\n                    <jats:p>\n                      <jats:underline>Definition of AKI subtypes<\/jats:underline>\n                      : subclinical AKI (KDIGO negative AND Ratio-positive), clinical AKI (KDIGO positive AND Ratio-negative) and combined AKI (KDIGO positive AND Ratio-positive) with urinary NGAL\/hepcidin-25 ratio-positive cut-off at 85% specificity for in-hospital death. AKI, acute kidney injury. AUC, area under the curve. NGAL, neutrophil gelatinase-associated lipocalin. KDIGO, Kidney Disease Improving Global Outcomes Initiative AKI definition.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s40620-021-01063-5","type":"journal-article","created":{"date-parts":[[2021,5,24]],"date-time":"2021-05-24T06:02:43Z","timestamp":1621836163000},"page":"597-605","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["NGAL\/hepcidin-25 ratio and AKI subtypes in patients following cardiac surgery: a prospective observational study"],"prefix":"10.1093","volume":"35","clinical-trial-number":[{"clinical-trial-number":"nct00672334","registry":"10.18810\/clinical-trials-gov"}],"author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1195-6871","authenticated-orcid":false,"given":"Saban","family":"Elitok","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7847-8552","authenticated-orcid":false,"given":"Prasad","family":"Devarajan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1650-8939","authenticated-orcid":false,"given":"Rinaldo","family":"Bellomo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0714-6160","authenticated-orcid":false,"given":"Berend","family":"Isermann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8212-7416","authenticated-orcid":false,"given":"Michael","family":"Haase","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6881-2249","authenticated-orcid":false,"given":"Anja","family":"Haase-Fielitz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2021,5,24]]},"reference":[{"key":"1063_CR1","doi-asserted-by":"publisher","first-page":"697","DOI":"10.1038\/nrneph.2017.119","volume":"13","author":"Y Wang","year":"2017","unstructured":"Wang Y, Bellomo R (2017) Cardiac surgery-associated acute kidney injury: risk factors, pathophysiology and treatment. Nat Rev Nephrol 13:697\u2013711. https:\/\/doi.org\/10.1038\/nrneph.2017.119","journal-title":"Nat Rev Nephrol"},{"key":"1063_CR2","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/kisup.2012.1","volume":"2","author":"JA Kellum","year":"2012","unstructured":"Kellum JA, Lameire N, Aspelin P et al (2012) Kidney disease: improving global outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO clinical practice guideline for acute kidney injury. Kidney Int Suppl 2:1\u2013138","journal-title":"Kidney Int Suppl"},{"key":"1063_CR3","doi-asserted-by":"publisher","first-page":"32","DOI":"10.1111\/nep.13663","volume":"25","author":"T Thammathiwat","year":"2020","unstructured":"Thammathiwat T, Tiranathanagul K, Srisawat N, Susantitaphong P, Praditpornsilpa K, Eiam-Ong S (2020) Clinical and subclinical acute kidney injury in multidrug-resistant septic patients treated with colistimethate sodium: Incidence and clinical outcomes. Nephrology (Carlton) 25:32\u201339. https:\/\/doi.org\/10.1111\/nep.13663","journal-title":"Nephrology (Carlton)"},{"key":"1063_CR4","doi-asserted-by":"publisher","first-page":"822","DOI":"10.1164\/rccm.201910-1950OC","volume":"202","author":"F D\u00e9pret","year":"2020","unstructured":"D\u00e9pret F, Hollinger A, Cariou A et al (2020) Incidence and outcome of subclinical acute kidney injury using penKid in critically Ill patients. Am J Respir Crit Care Med 202:822\u2013829. https:\/\/doi.org\/10.1164\/rccm.201910-1950OC","journal-title":"Am J Respir Crit Care Med"},{"key":"1063_CR5","doi-asserted-by":"publisher","first-page":"2441","DOI":"10.1016\/j.jtcvs.2017.12.056","volume":"155","author":"C Albert","year":"2018","unstructured":"Albert C, Albert A, Kube J et al (2018) Urinary biomarkers may provide prognostic information for subclinical acute kidney injury after cardiac surgery. J Thorac Cardiovasc Surg 155:2441\u20132452. https:\/\/doi.org\/10.1016\/j.jtcvs.2017.12.056","journal-title":"J Thorac Cardiovasc Surg"},{"key":"1063_CR6","doi-asserted-by":"publisher","first-page":"187","DOI":"10.3109\/0886022X.2014.991994","volume":"37","author":"K Akrawinthawong","year":"2015","unstructured":"Akrawinthawong K, Ricci J, Cannon L, Dixon S, Kupfer K, Stivers D, Alexander P, David S, McCullough PA (2015) Subclinical and clinical contrast-induced acute kidney injury: data from a novel blood marker for determining the risk of developing contrast-induced nephropathy (ENCINO), a prospective study. Ren Fail 37:187\u2013191. https:\/\/doi.org\/10.3109\/0886022X.2014.991994","journal-title":"Ren Fail"},{"key":"1063_CR7","doi-asserted-by":"publisher","first-page":"169","DOI":"10.1186\/1471-2369-15-169","volume":"15","author":"E Cho","year":"2014","unstructured":"Cho E, Kim SC, Kim MG, Jo SK, Cho WY, Kim HK (2014) The incidence and risk factors of acute kidney injury after hepatobiliary surgery: a prospective observational study. BMC Nephrol 15:169. https:\/\/doi.org\/10.1186\/1471-2369-15-169","journal-title":"BMC Nephrol"},{"key":"1063_CR8","doi-asserted-by":"publisher","first-page":"R29","DOI":"10.1186\/cc12510","volume":"17","author":"S Di Somma","year":"2013","unstructured":"Di Somma S, Magrini L, De Berardinis B, Marino R, Ferri E, Moscatelli P, Ballarino P, Carpinteri G, Noto P, Gliozzo B, Paladino L, Di Stasio E (2013) Additive value of blood neutrophil gelatinase-associated lipocalin to clinical judgement in acute kidney injury diagnosis and mortality prediction in patients hospitalized from the emergency department. Crit Care 17:R29. https:\/\/doi.org\/10.1186\/cc12510","journal-title":"Crit Care"},{"key":"1063_CR9","doi-asserted-by":"publisher","first-page":"246","DOI":"10.1016\/j.jacc.2011.10.854","volume":"59","author":"TL Nickolas","year":"2012","unstructured":"Nickolas TL, Schmidt-Ott KM, Canetta P et al (2012) Diagnostic and prognostic stratification in the emergency department using urinary biomarkers of nephron damage: a multicenter prospective cohort study. J Am Coll Cardiol 59:246\u2013255. https:\/\/doi.org\/10.1016\/j.jacc.2011.10.854","journal-title":"J Am Coll Cardiol"},{"key":"1063_CR10","doi-asserted-by":"publisher","first-page":"18148","DOI":"10.1016\/S0021-9258(19)37165-0","volume":"267","author":"G Balla","year":"1992","unstructured":"Balla G, Jacob HS, Balla J et al (1992) Ferritin: a cytoprotective antioxidant strategem of endothelium. J Biol Chem 267:18148\u201318153","journal-title":"J Biol Chem"},{"key":"1063_CR11","doi-asserted-by":"publisher","first-page":"493","DOI":"10.1681\/ASN.2018100979","volume":"30","author":"DE Leaf","year":"2019","unstructured":"Leaf DE, Rajapurkar M, Lele SS et al (2019) Iron, hepcidin, and death in human AKI. J Am Soc Nephrol 30:493\u2013504. https:\/\/doi.org\/10.1681\/ASN.2018100979","journal-title":"J Am Soc Nephrol"},{"key":"1063_CR12","doi-asserted-by":"publisher","first-page":"131","DOI":"10.3343\/alm.2020.40.2.131","volume":"40","author":"C Albert","year":"2020","unstructured":"Albert C, Haase M, Albert A et al (2020) Urinary biomarkers may complement the Cleveland score for prediction of adverse kidney events after cardiac surgery: a pilot study. Ann Lab Med 40:131\u2013141. https:\/\/doi.org\/10.3343\/alm.2020.40.2.131","journal-title":"Ann Lab Med"},{"key":"1063_CR13","doi-asserted-by":"publisher","first-page":"e1001426","DOI":"10.1371\/journal.pmed.1001426","volume":"10","author":"M Haase","year":"2013","unstructured":"Haase M, Haase-Fielitz A, Plass M et al (2013) Prophylactic perioperative sodium bicarbonate to prevent acute kidney injury following open heart surgery: a multicenter double-blinded randomized controlled trial. PLoS Med 10:e1001426. https:\/\/doi.org\/10.1371\/journal.pmed.1001426","journal-title":"PLoS Med"},{"key":"1063_CR14","doi-asserted-by":"publisher","first-page":"1495","DOI":"10.1016\/j.ijsu.2014.07.013","volume":"12","author":"E von Elm","year":"2014","unstructured":"von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP (2014) The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Int J Surg 12:1495\u20131499. https:\/\/doi.org\/10.1016\/j.ijsu.2014.07.013","journal-title":"Int J Surg"},{"key":"1063_CR15","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1016\/s1010-7940(99)00134-7","volume":"16","author":"SA Nashef","year":"1999","unstructured":"Nashef SA, Roques F, Michel P, Gauducheau E, Lemeshow S, Salamon R (1999) European system for cardiac operative risk evaluation (EuroSCORE). Eur J Cardiothorac Surg 16:9\u201313. https:\/\/doi.org\/10.1016\/s1010-7940(99)00134-7","journal-title":"Eur J Cardiothorac Surg"},{"key":"1063_CR16","doi-asserted-by":"publisher","first-page":"513","DOI":"10.1038\/ki.2013.374","volume":"85","author":"PT Murray","year":"2014","unstructured":"Murray PT, Mehta RL, Shaw A et al (2014) ADQI 10 workgroup. Potential use of biomarkers in acute kidney injury: report and summary of recommendations from the 10th Acute Dialysis Quality Initiative consensus conference. Kidney Int 85:513\u2013521. https:\/\/doi.org\/10.1038\/ki.2013.374","journal-title":"Kidney Int"},{"key":"1063_CR17","doi-asserted-by":"publisher","first-page":"2301","DOI":"10.1016\/j.jacc.2011.08.017","volume":"58","author":"CD Krawczeski","year":"2011","unstructured":"Krawczeski CD, Goldstein SL, Woo JG et al (2011) Temporal relationship and predictive value of urinary acute kidney injury biomarkers after pediatric cardiopulmonary bypass. J Am Coll Cardiol 58:2301\u20132309. https:\/\/doi.org\/10.1016\/j.jacc.2011.08.017","journal-title":"J Am Coll Cardiol"},{"key":"1063_CR18","doi-asserted-by":"publisher","first-page":"1752","DOI":"10.1016\/j.jacc.2010.11.051","volume":"57","author":"M Haase","year":"2011","unstructured":"Haase M, Devarajan P, Haase-Fielitz A et al (2011) The outcome of neutrophil gelatinase-associated lipocalin-positive subclinical acute kidney injury: a multicenter pooled analysis of prospective studies. J Am Coll Cardiol 57:1752\u20131761. https:\/\/doi.org\/10.1016\/j.jacc.2010.11.051","journal-title":"J Am Coll Cardiol"},{"key":"1063_CR19","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1016\/j.semnephrol.2017.09.002","volume":"38","author":"DG Moledina","year":"2018","unstructured":"Moledina DG, Parikh CR (2018) Phenotyping of acute kidney injury: beyond serum creatinine. Semin Nephrol 38:3\u201311. https:\/\/doi.org\/10.1016\/j.semnephrol.2017.09.002","journal-title":"Semin Nephrol"},{"key":"1063_CR20","doi-asserted-by":"publisher","first-page":"2060","DOI":"10.1681\/ASN.2019060595","volume":"30","author":"S Sharma","year":"2019","unstructured":"Sharma S, Leaf DE (2019) Iron chelation as a potential therapeutic strategy for AKI prevention. J Am Soc Nephrol 30:2060\u20132071. https:\/\/doi.org\/10.1681\/ASN.2019060595","journal-title":"J Am Soc Nephrol"},{"key":"1063_CR21","doi-asserted-by":"publisher","first-page":"2720","DOI":"10.1681\/ASN.2015040461","volume":"27","author":"RP van Swelm","year":"2016","unstructured":"van Swelm RP, Wetzels JF, Verweij VG et al (2016) Renal handling of circulating and renal-synthesized hepcidin and its protective effects against hemoglobin-mediated kidney injury. J Am Soc Nephrol 27:2720\u20132732. https:\/\/doi.org\/10.1681\/ASN.2015040461","journal-title":"J Am Soc Nephrol"},{"key":"1063_CR22","doi-asserted-by":"publisher","first-page":"361","DOI":"10.1677\/joe.1.05729","volume":"184","author":"H Kulaksiz","year":"2005","unstructured":"Kulaksiz H, Theilig F, Bachmann S et al (2005) The iron-regulatory peptide hormone hepcidin: expression and cellular localization in the mammalian kidney. J Endocrinol 184:361\u2013370. https:\/\/doi.org\/10.1677\/joe.1.05729","journal-title":"J Endocrinol"},{"key":"1063_CR23","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1007\/s40620-020-00875-1","volume":"34","author":"E Russo","year":"2021","unstructured":"Russo E, Esposito P, Taramasso L et al (2021) Kidney disease and all-cause mortality in patients with COVID-19 hospitalized in Genoa, Northern Italy. J Nephrol 34:173\u2013183. https:\/\/doi.org\/10.1007\/s40620-020-00875-1","journal-title":"J Nephrol"},{"key":"1063_CR24","doi-asserted-by":"publisher","first-page":"1551","DOI":"10.1007\/s00134-016-4670-3","volume":"43","author":"M Meersch","year":"2017","unstructured":"Meersch M, Schmidt C, Hoffmeier A et al (2017) Prevention of cardiac surgery-associated AKI by implementing the KDIGO guidelines in high risk patients identified by biomarkers: the PrevAKI randomized controlled trial. Intensive Care Med 43:1551\u20131561. https:\/\/doi.org\/10.1007\/s00134-016-4670-3","journal-title":"Intensive Care Med"},{"key":"1063_CR25","doi-asserted-by":"publisher","first-page":"289","DOI":"10.3238\/arztebl.2020.0289","volume":"117","author":"A Haase-Fielitz","year":"2020","unstructured":"Haase-Fielitz A, Elitok S, Schostak M et al (2020) The effects of intensive versus routine treatment in patients with acute kidney injury. Dtsch Arztebl Int 117:289\u2013296. https:\/\/doi.org\/10.3238\/arztebl.2020.0289","journal-title":"Dtsch Arztebl Int"},{"key":"1063_CR26","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1053\/j.ajkd.2016.10.004","volume":"69","author":"CV Thakar","year":"2017","unstructured":"Thakar CV (2017) Long-term outcomes of acute kidney injury: the power and pitfalls of observational\/population-based studies. Am J Kidney Dis 69:3\u20134. https:\/\/doi.org\/10.1053\/j.ajkd.2016.10.004","journal-title":"Am J Kidney Dis"},{"key":"1063_CR27","doi-asserted-by":"publisher","first-page":"2190","DOI":"10.1001\/jama.2016.5828","volume":"315","author":"A Zarbock","year":"2016","unstructured":"Zarbock A, Kellum JA, Schmidt C et al (2016) Effect of early vs delayed initiation of renal replacement therapy on mortality in critically ill patients with acute kidney injury: the ELAIN randomized clinical trial. JAMA 315:2190\u20132199. https:\/\/doi.org\/10.1001\/jama.2016.5828","journal-title":"JAMA"},{"key":"1063_CR28","doi-asserted-by":"publisher","first-page":"187","DOI":"10.1053\/j.ajkd.2019.06.011","volume":"75","author":"CR Parikh","year":"2020","unstructured":"Parikh CR, Liu C, Mor MK et al (2020) Kidney biomarkers of injury and repair as predictors of contrast-associated AKI: a substudy of the PRESERVE trial. Am J Kidney Dis 75:187\u2013194. https:\/\/doi.org\/10.1053\/j.ajkd.2019.06.011","journal-title":"Am J Kidney Dis"}],"container-title":["Journal of Nephrology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s40620-021-01063-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s40620-021-01063-5\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s40620-021-01063-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T15:56:46Z","timestamp":1777564606000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/joneph\/article\/35\/2\/597\/8328607"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,24]]},"references-count":28,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2022,3]]}},"alternative-id":["1063"],"URL":"https:\/\/doi.org\/10.1007\/s40620-021-01063-5","relation":{},"ISSN":["1121-8428","1724-6059"],"issn-type":[{"value":"1121-8428","type":"print"},{"value":"1724-6059","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,24]]},"assertion":[{"value":"24 March 2021","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"9 May 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"24 May 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Saban Elitok: None. Prasad Devarajan: This author is a co-inventor on patents submitted for the use of NGAL as a biomarker of kidney injury. Rinaldo Bellomo: None. Berend Isermann: None. Anja Haase-Fielitz: None. Michael Haase: This author is a consultant to FastBiomedical and has received lecture honoraria and travel reimbursement from Siemens Healthcare Diagnostics, Abbott Diagnostics, Roche, Alere, Astute and Baxter on unrelated work.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}},{"value":"The study was approved by the local ethics committee of the University of Magdeburg, Germany (registry number No. 61\/14, 2014) and the Charit\u00e9\u2014Universit\u00e4tsmedizin Berlin, Germany (registry number ZS EK 11 654\/07). The procedures used in this study adhere to the tenets of the Declaration of Helsinki.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval"}},{"value":"Written informed consent to participate was obtained from all individual participants included in the study.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to participate"}},{"value":"Written informed consent to publish was obtained from all individual participants included in the study.","order":5,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"Written informed consent to participate and to publish was obtained from all individual participants included in the study.","order":6,"name":"Ethics","group":{"name":"EthicsHeading","label":"Informed consent"}}]}}