{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,20]],"date-time":"2026-10-20T18:49:15Z","timestamp":1792522155840,"version":"4.5.0"},"reference-count":40,"publisher":"Oxford University Press (OUP)","issue":"6","license":[{"start":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T00:00:00Z","timestamp":1780444800000},"content-version":"vor","delay-in-days":2,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100009780","name":"Region Sk\u00e5ne","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100009780","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,6,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Calprotectin, a neutrophil activation marker, is a promising diagnostic biomarker for infection and sepsis, but its usefulness in the emergency department (ED) is unclear. The aim of this study was to investigate the diagnostic value of calprotectin for sepsis and the source of infection in the ED.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A total of 583 prospectively included patients presenting with suspected sepsis to the ED of a university hospital in southern Sweden were analyzed. Calprotectin was measured in plasma samples obtained at admission.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Mean age was 69 years and 49% were female. Calprotectin discriminated between sepsis and noninfectious systemic inflammatory response syndrome with an area under the curve (AUC) of 0.63, but was not an independent predictor in multivariable analysis including C-reactive protein (CRP). The Modified Early Warning Score did not show any discriminatory ability. Calprotectin and CRP discriminated between lower respiratory tract infection and (1) upper respiratory tract infection, (2) urinary tract infection, and (3) other sources of infection. Addition of calprotectin to CRP significantly increased the AUC for lower versus upper respiratory tract infection and lower respiratory tract infection versus urinary tract infection. Calprotectin was an independent predictor for all outcomes while CRP was only an independent predictor of lower versus upper respiratory tract infection.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Calprotectin may improve differentiation of lower respiratory tract infections from upper respiratory tract infections and urinary tract infections in patients presenting to the ED with sepsis. Further research is needed to clarify if calprotectin adds diagnostic value to standard clinical assessment.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ofid\/ofag331","type":"journal-article","created":{"date-parts":[[2026,5,31]],"date-time":"2026-05-31T11:36:07Z","timestamp":1780227367000},"source":"Crossref","is-referenced-by-count":2,"title":["Calprotectin as a Diagnostic Marker for Lower Respiratory Tract Infection and Sepsis in the Emergency Department"],"prefix":"10.1093","volume":"13","author":[{"given":"Martin","family":"Wollmer","sequence":"first","affiliation":[{"name":"Department of Emergency and Internal Medicine, Sk\u00e5ne University Hospital , Malm\u00f6 ,","place":["Sweden"]},{"name":"Department of Clinical Sciences Malm\u00f6, Lund University , Lund ,","place":["Sweden"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7314-2240","authenticated-orcid":false,"given":"Torgny","family":"Wessman","sequence":"additional","affiliation":[{"name":"Department of Emergency and Internal Medicine, Sk\u00e5ne University Hospital , Malm\u00f6 ,","place":["Sweden"]},{"name":"Department of Clinical Sciences Malm\u00f6, Lund University , Lund ,","place":["Sweden"]},{"name":"Department of Clinical Sciences Lund, Lund University , Lund ,","place":["Sweden"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2581-484X","authenticated-orcid":false,"given":"Olle","family":"Melander","sequence":"additional","affiliation":[{"name":"Department of Emergency and Internal Medicine, Sk\u00e5ne University Hospital , Malm\u00f6 ,","place":["Sweden"]},{"name":"Department of Clinical Sciences Malm\u00f6, Lund University , Lund ,","place":["Sweden"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3161-0402","authenticated-orcid":false,"given":"Anders","family":"Larsson","sequence":"additional","affiliation":[{"name":"Department of Medical Sciences, Uppsala University , Uppsala ,","place":["Sweden"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1170-5183","authenticated-orcid":false,"given":"Toralph","family":"Ruge","sequence":"additional","affiliation":[{"name":"Department of Emergency and Internal Medicine, Sk\u00e5ne University Hospital , Malm\u00f6 ,","place":["Sweden"]},{"name":"Department of Clinical Sciences Malm\u00f6, Lund University , Lund ,","place":["Sweden"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,6,3]]},"reference":[{"key":"2026061009403309400_ofag331-B1","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1164\/rccm.201504-0781OC","article-title":"Assessment of global incidence and mortality of hospital-treated sepsis. Current estimates and limitations","volume":"193","author":"Fleischmann","year":"2016","journal-title":"Am J Respir Crit Care Med"},{"key":"2026061009403309400_ofag331-B2","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.ajem.2025.01.054","article-title":"Emergency medicine updates: management of sepsis and septic shock","volume":"90","author":"Long","year":"2025","journal-title":"Am J Emerg Med"},{"key":"2026061009403309400_ofag331-B3","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1038\/s41522-018-0048-3","article-title":"Precision antimicrobial therapeutics: the path of least resistance?","volume":"4","author":"Spaulding","year":"2018","journal-title":"NPJ Biofilms Microbiomes"},{"key":"2026061009403309400_ofag331-B4","doi-asserted-by":"crossref","first-page":"801","DOI":"10.1001\/jama.2016.0287","article-title":"The Third International Consensus definitions for sepsis and septic shock (sepsis-3)","volume":"315","author":"Singer","year":"2016","journal-title":"JAMA"},{"key":"2026061009403309400_ofag331-B5","doi-asserted-by":"crossref","first-page":"530","DOI":"10.1007\/s00134-003-1662-x","article-title":"2001 SCCM\/ESICM\/ACCP\/ATS\/SIS international sepsis definitions conference","volume":"29","author":"Levy","year":"2003","journal-title":"Intensive Care Med"},{"key":"2026061009403309400_ofag331-B6","doi-asserted-by":"crossref","first-page":"646","DOI":"10.1016\/j.chest.2017.12.015","article-title":"A comparison of the quick-SOFA and systemic inflammatory response syndrome criteria for the diagnosis of sepsis and prediction of mortality: a systematic review and meta-analysis","volume":"153","author":"Serafim","year":"2018","journal-title":"Chest"},{"key":"2026061009403309400_ofag331-B7","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/j.ajem.2020.07.077","article-title":"Comparison the accuracy of early warning scores with qSOFA and SIRS for predicting sepsis in the emergency department","volume":"46","author":"Wattanasit","year":"2021","journal-title":"Am J Emerg Med"},{"key":"2026061009403309400_ofag331-B8","doi-asserted-by":"crossref","first-page":"e1063","DOI":"10.1097\/CCM.0000000000005337","article-title":"Surviving sepsis campaign: international guidelines for management of sepsis and septic shock 2021","volume":"49","author":"Evans","year":"2021","journal-title":"Crit Care Med"},{"key":"2026061009403309400_ofag331-B9","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.1172\/JCI200318921","article-title":"C-reactive protein: a critical update","volume":"111","author":"Pepys","year":"2003","journal-title":"J Clin Invest"},{"key":"2026061009403309400_ofag331-B10","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.pharmthera.2016.07.015","article-title":"S100a8\/A9: from basic science to clinical application","volume":"167","author":"Pruenster","year":"2016","journal-title":"Pharmacol Ther"},{"key":"2026061009403309400_ofag331-B11","doi-asserted-by":"crossref","first-page":"1098","DOI":"10.1164\/rccm.200810-1552OC","article-title":"Expression and role of myeloid-related protein-14 in clinical and experimental sepsis","volume":"180","author":"van Zoelen","year":"2009","journal-title":"Am J Respir Crit Care Med"},{"key":"2026061009403309400_ofag331-B12","doi-asserted-by":"crossref","first-page":"1278","DOI":"10.1016\/j.ajem.2015.06.025","article-title":"Diagnostic and prognostic value of myeloid-related protein complex 8\/14 for sepsis","volume":"33","author":"Gao","year":"2015","journal-title":"Am J Emerg Med"},{"key":"2026061009403309400_ofag331-B13","doi-asserted-by":"crossref","first-page":"4208","DOI":"10.1038\/s41598-020-61094-z","article-title":"Calprotectin, a new biomarker for diagnosis of acute respiratory infections","volume":"10","author":"Havelka","year":"2020","journal-title":"Sci Rep"},{"key":"2026061009403309400_ofag331-B14","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1186\/s12873-019-0283-9","article-title":"Proenkephalin a 119-159 (penKid)\u2014a novel biomarker for acute kidney injury in sepsis: an observational study","volume":"19","author":"Rosenqvist","year":"2019","journal-title":"BMC Emerg Med"},{"key":"2026061009403309400_ofag331-B15","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1093\/qjmed\/94.10.521","article-title":"Validation of a modified early warning score in medical admissions","volume":"94","author":"Subbe","year":"2001","journal-title":"QJM"},{"key":"2026061009403309400_ofag331-B16","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1016\/j.annemergmed.2024.02.009","article-title":"Early physician gestalt versus usual screening tools for the prediction of sepsis in critically ill emergency patients","volume":"84","author":"Knack","year":"2024","journal-title":"Ann Emerg Med"},{"key":"2026061009403309400_ofag331-B17","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1097\/SHK.0000000000001981","article-title":"Diagnostic accuracy and added value of infection biomarkers in patients with possible sepsis in the emergency department","volume":"58","author":"Christensen","year":"2022","journal-title":"Shock"},{"key":"2026061009403309400_ofag331-B18","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1186\/s12879-024-09394-x","article-title":"Blood calprotectin as a biomarker for infection and sepsis\u2014the prospective CASCADE trial","volume":"24","author":"Diehl-Wiesenecker","year":"2024","journal-title":"BMC Infect Dis"},{"key":"2026061009403309400_ofag331-B19","doi-asserted-by":"crossref","first-page":"15529","DOI":"10.1038\/s41598-025-95420-0","article-title":"Calprotectin as a sepsis diagnostic marker in critical care: a retrospective observational study","volume":"15","author":"Lengquist","year":"2025","journal-title":"Sci Rep"},{"key":"2026061009403309400_ofag331-B20","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1080\/00365513.2019.1703216","article-title":"Calprotectin is superior to procalcitonin as a sepsis marker and predictor of 30-day mortality in intensive care patients","volume":"80","author":"Larsson","year":"2020","journal-title":"Scand J Clin Lab Invest"},{"key":"2026061009403309400_ofag331-B21","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.cca.2021.12.011","article-title":"Prognostic value of circulating calprotectin levels on the clinical course of COVID-19 differs between serum, heparin, EDTA and citrate sample types","volume":"525","author":"Nevejan","year":"2022","journal-title":"Clin Chim Acta"},{"key":"2026061009403309400_ofag331-B22","doi-asserted-by":"crossref","first-page":"5852","DOI":"10.1002\/jcb.27870","article-title":"The diagnostic accuracy of procalcitonin and C-reactive protein for sepsis: a systematic review and meta-analysis","volume":"120","author":"Tan","year":"2019","journal-title":"J Cell Biochem"},{"key":"2026061009403309400_ofag331-B23","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/j.jemermed.2011.05.072","article-title":"Discriminative value of inflammatory biomarkers for suspected sepsis","volume":"43","author":"Tsalik","year":"2012","journal-title":"J Emerg Med"},{"key":"2026061009403309400_ofag331-B24","doi-asserted-by":"crossref","first-page":"968","DOI":"10.1186\/s12879-019-4618-7","article-title":"Diagnostic and prognostic value of interleukin-6, pentraxin 3, and procalcitonin levels among sepsis and septic shock patients: a prospective controlled study according to the Sepsis-3 definitions","volume":"19","author":"Song","year":"2019","journal-title":"BMC Infect Dis"},{"key":"2026061009403309400_ofag331-B25","doi-asserted-by":"crossref","first-page":"e0181704","DOI":"10.1371\/journal.pone.0181704","article-title":"Diagnostic accuracy of procalcitonin, neutrophil-lymphocyte count ratio, C-reactive protein, and lactate in patients with suspected bacterial sepsis","volume":"12","author":"Ljungstr\u00f6m","year":"2017","journal-title":"PLoS One"},{"key":"2026061009403309400_ofag331-B26","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1186\/s13054-020-02993-5","article-title":"Biomarkers of sepsis: time for a reappraisal","volume":"24","author":"Pierrakos","year":"2020","journal-title":"Crit Care"},{"key":"2026061009403309400_ofag331-B27","doi-asserted-by":"crossref","first-page":"1737","DOI":"10.1097\/01.CCM.0000063440.19188.ED","article-title":"Comparison of procalcitonin and C-reactive protein as markers of sepsis","volume":"31","author":"Luzzani","year":"2003","journal-title":"Crit Care Med"},{"key":"2026061009403309400_ofag331-B28","first-page":"466","article-title":"Procalcitonin and sepsis in the emergency department: an update","volume":"25","author":"Velissaris","year":"2021","journal-title":"Eur Rev Med Pharmacol Sci"},{"key":"2026061009403309400_ofag331-B29","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.ajem.2025.01.055","article-title":"Emergency medicine updates: evaluation and diagnosis of sepsis and septic shock","volume":"90","author":"Long","year":"2025","journal-title":"Am J Emerg Med"},{"key":"2026061009403309400_ofag331-B30","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1016\/j.jinf.2012.08.004","article-title":"Combination of biomarkers for the discrimination between bacterial and viral lower respiratory tract infections","volume":"65","author":"ten Oever","year":"2012","journal-title":"J Infect"},{"key":"2026061009403309400_ofag331-B31","doi-asserted-by":"crossref","first-page":"1776","DOI":"10.3390\/jcm13061776","article-title":"The diagnostic accuracy of procalcitonin, soluble urokinase-type plasminogen activator receptors, and C-reactive protein in diagnosing urinary tract infections in the emergency department\u2014a diagnostic accuracy study","volume":"13","author":"Hertz","year":"2024","journal-title":"J Clin Med"},{"key":"2026061009403309400_ofag331-B32","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.diagmicrobio.2018.10.006","article-title":"Calprotectin and calgranulin C serum levels in bacterial sepsis","volume":"93","author":"Bart\u00e1kov\u00e1","year":"2019","journal-title":"Diagn Microbiol Infect Dis"},{"key":"2026061009403309400_ofag331-B33","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1080\/00365513.2021.1980223","article-title":"Plasma calprotectin in the emergency department: a potential clinical biomarker for patients with infectious diseases","volume":"81","author":"Wollmer","year":"2021","journal-title":"Scand J Clin Lab Invest"},{"key":"2026061009403309400_ofag331-B34","doi-asserted-by":"crossref","first-page":"115674","DOI":"10.1016\/j.biopha.2023.115674","article-title":"S100a8\/A9: an emerging player in sepsis and sepsis-induced organ injury","volume":"168","author":"Wang","year":"2023","journal-title":"Biomed Pharmacother"},{"key":"2026061009403309400_ofag331-B35","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1186\/s12964-025-02098-y","article-title":"Dysregulation of neutrophil in sepsis: recent insights and advances","volume":"23","author":"Zhang","year":"2025","journal-title":"Cell Commun Signal"},{"key":"2026061009403309400_ofag331-B36","doi-asserted-by":"crossref","first-page":"1722","DOI":"10.3389\/fimmu.2020.01722","article-title":"Pulmonary innate immune response determines the outcome of inflammation during pneumonia and sepsis-associated acute lung injury","volume":"11","author":"Kumar","year":"2020","journal-title":"Front Immunol"},{"key":"2026061009403309400_ofag331-B37","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1007\/s00011-021-01516-4","article-title":"Circulating levels of calprotectin, a signature of neutrophil activation in prediction of severe respiratory failure in COVID-19 patients: a multicenter, prospective study (CalCov study)","volume":"71","author":"Garc\u00eda de Guadiana-Romualdo","year":"2022","journal-title":"Inflamm Res"},{"key":"2026061009403309400_ofag331-B38","doi-asserted-by":"crossref","first-page":"2939","DOI":"10.2147\/JIR.S457547","article-title":"Serum Mrp 8\/14 as a potential biomarker for predicting the occurrence of acute respiratory distress syndrome induced by sepsis: a retrospective controlled study","volume":"17","author":"Sun","year":"2024","journal-title":"J Inflamm Res"},{"key":"2026061009403309400_ofag331-B39","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1016\/j.chom.2020.12.016","article-title":"Induction of alarmin S100A8\/A9 mediates activation of aberrant neutrophils in the pathogenesis of COVID-19","volume":"29","author":"Guo","year":"2021","journal-title":"Cell Host Microbe"},{"key":"2026061009403309400_ofag331-B40","doi-asserted-by":"crossref","first-page":"12923","DOI":"10.3390\/ijms222312923","article-title":"Targeting S100A9 reduces neutrophil recruitment, inflammation and lung damage in abdominal sepsis","volume":"22","author":"Ding","year":"2021","journal-title":"Int J Mol Sci"}],"container-title":["Open Forum Infectious Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ofid\/advance-article-pdf\/doi\/10.1093\/ofid\/ofag331\/68455646\/ofag331.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ofid\/article-pdf\/13\/6\/ofag331\/68455646\/ofag331.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ofid\/article-pdf\/13\/6\/ofag331\/68455646\/ofag331.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T13:40:42Z","timestamp":1781098842000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ofid\/article\/doi\/10.1093\/ofid\/ofag331\/8700163"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6]]},"references-count":40,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2026,6,2]]}},"URL":"https:\/\/doi.org\/10.1093\/ofid\/ofag331","relation":{},"ISSN":["2328-8957"],"issn-type":[{"value":"2328-8957","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,6]]},"published":{"date-parts":[[2026,6]]},"article-number":"ofag331"}}