{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T14:09:35Z","timestamp":1790172575620,"version":"4.1.0"},"reference-count":28,"publisher":"Public Library of Science (PLoS)","issue":"6","license":[{"start":{"date-parts":[[2021,6,10]],"date-time":"2021-06-10T00:00:00Z","timestamp":1623283200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FIS-FEDER","award":["PI13\/01538"],"award-info":[{"award-number":["PI13\/01538"]}]},{"DOI":"10.13039\/501100008425","name":"Conseller\u00eda de Cultura, Educaci\u00f3n e Ordenaci\u00f3n Universitaria, Xunta de Galicia","doi-asserted-by":"crossref","award":["CN\/2014"],"award-info":[{"award-number":["CN\/2014"]}],"id":[{"id":"10.13039\/501100008425","id-type":"DOI","asserted-by":"crossref"}]},{"name":"AEER"},{"name":"SOGAPAR (2014)."},{"DOI":"10.13039\/501100007509","name":"SEPAR","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100007509","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>In previous studies, measuring the levels of calprotectin in patients with pleural effusion (PE) was an exceptionally accurate way to predict malignancy. Here, we evaluated a rapid method for the measurement of calprotectin levels as a useful parameter in the diagnosis of malignant pleural effusion (MPE) in order to minimise invasive diagnostic tests. Calprotectin levels were measured with Quantum Blue<jats:sup>\u00ae<\/jats:sup> sCAL (QB<jats:sup>\u00ae<\/jats:sup>sCAL) and compared with the gold standard reference ELISA method. Calprotectin levels in patients with benign pleural effusion (BPE) were significantly higher (<jats:italic>p &lt;<\/jats:italic> 0.0001) than for MPE patients. We measured the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratios (LRs) for a cut-off value of \u2264 14,150 ng\/mL; the diagnostic accuracy was 64%. The odds ratio for PE calprotectin levels was 10.938 (95% CI [4.133 \u2212 28.947]). The diagnostic performance of calprotectin concentration was better for predicting MPE compared to other individual parameters. Comparison of two assays showed a slope of 1.084, an intercept of 329.7, and a Pearson correlation coefficient of 0.798. The Bland\u2013Altman test showed a positive bias for the QB<jats:sup>\u00ae<\/jats:sup>sCAL method compared to ELISA fCAL<jats:sup>\u00ae<\/jats:sup>. Clinical concordance between both these methods was 88.5% with a Cohen kappa index of 0.76 (95% CI [0.68 \u2212 0.84]). We concluded that QB<jats:sup>\u00ae<\/jats:sup>sCAL is a fast, reliable, and non-invasive diagnostic tool for diagnosing MPE and represents an alternative to ELISA that could be implemented in medical emergencies.<\/jats:p>","DOI":"10.1371\/journal.pone.0252714","type":"journal-article","created":{"date-parts":[[2021,6,10]],"date-time":"2021-06-10T23:45:05Z","timestamp":1623368705000},"page":"e0252714","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":7,"title":["A rapid calprotectin test for the diagnosis of pleural effusion"],"prefix":"10.1371","volume":"16","author":[{"given":"Pedro","family":"Casado-Rey","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0203-3514","authenticated-orcid":true,"given":"Lorena","family":"V\u00e1zquez-Iglesias","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maribel","family":"Botana-Rial","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar\u00eda Amalia","family":"Andrade-Olivi\u00e9","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luc\u00eda","family":"Ferreiro-Fern\u00e1ndez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Esther","family":"San Jos\u00e9 Capilla","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Nu\u00f1ez-Ares","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elena","family":"Bollo de Miguel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Virginia","family":"Pajares-Ru\u00edz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alberto","family":"Fern\u00e1ndez-Villar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,6,10]]},"reference":[{"key":"pone.0252714.ref001","doi-asserted-by":"crossref","first-page":"1754","DOI":"10.1056\/NEJMra1403503","article-title":"Pleural Disease","volume":"378","author":"D Feller-Kopman","year":"2018","journal-title":"N Engl J Med"},{"issue":"6","key":"pone.0252714.ref002","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/j.arbr.2014.04.007","article-title":"Recommendations of diagnosis and treatment of pleural effusion. Update","volume":"50","author":"V Villena Garrido","year":"2014","journal-title":"Arch Bronconeumol"},{"issue":"2","key":"pone.0252714.ref003","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1111\/j.1440-1843.2011.02100.x","article-title":"Getting the most from pleural fluid analysis","volume":"17","author":"SA Sahn","year":"2012","journal-title":"Respirology"},{"issue":"6","key":"pone.0252714.ref004","doi-asserted-by":"crossref","first-page":"737","DOI":"10.2217\/fon.11.45","article-title":"Diagnostic molecular biomarkers for malignant pleural effusions","volume":"7","author":"KB Sriram","year":"2011","journal-title":"Future Oncol"},{"issue":"11","key":"pone.0252714.ref005","doi-asserted-by":"crossref","first-page":"1876","DOI":"10.1038\/bjc.2012.478","article-title":"Calprotectin: a novel biomarker for the diagnosis of pleural effusion","volume":"107","author":"N Sanchez-Otero","year":"2012","journal-title":"Br J Cancer"},{"issue":"8","key":"pone.0252714.ref006","doi-asserted-by":"crossref","first-page":"1511","DOI":"10.1016\/j.jprot.2010.03.005","article-title":"On the identification of biomarkers for non-small cell lung cancer in serum and pleural effusion","volume":"73","author":"AM Rodriguez-Pineiro","year":"2010","journal-title":"J Proteomics"},{"issue":"1","key":"pone.0252714.ref007","doi-asserted-by":"crossref","first-page":"5679","DOI":"10.1038\/s41598-020-62388-y","article-title":"Validation of Calprotectin As a Novel Biomarker For The Diagnosis of Pleural Effusion: a Multicentre Trial","volume":"10","author":"M Botana-Rial","year":"2020","journal-title":"Sci Rep"},{"issue":"8","key":"pone.0252714.ref008","doi-asserted-by":"crossref","first-page":"e172","DOI":"10.1515\/cclm-2016-0884","article-title":"Evaluation of an automated commercial ELISA method for calprotectin determination in pleural fluid","volume":"55","author":"L Vazquez-Iglesias","year":"2017","journal-title":"Clin Chem Lab Med"},{"issue":"Suppl 2","key":"pone.0252714.ref009","doi-asserted-by":"crossref","first-page":"ii32","DOI":"10.1136\/thx.2010.136994","article-title":"Management of a malignant pleural effusion: British Thoracic Society Pleural Disease Guideline 2010","volume":"65","author":"ME Roberts","year":"2010","journal-title":"Thorax"},{"issue":"3","key":"pone.0252714.ref010","first-page":"270","article-title":"Development of cancer diagnostics\u2014from biomarkers to clinical tests","volume":"4","author":"Y Wang","year":"2015","journal-title":"Translational Cancer Research"},{"key":"pone.0252714.ref011","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1007\/5584_2015_156","article-title":"Development and Evaluation of the New Predictive Models in Tuberculous Pleuritis","volume":"873","author":"J Klimiuk","year":"2015","journal-title":"Adv Exp Med Biol"},{"key":"pone.0252714.ref012","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/j.cmpb.2017.10.022","article-title":"Developing a new intelligent system for the diagnosis of tuberculous pleural effusion","volume":"153","author":"C Li","year":"2018","journal-title":"Comput Methods Programs Biomed"},{"issue":"1","key":"pone.0252714.ref013","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1111\/resp.12414","article-title":"Diagnostic role of inflammatory and anti-inflammatory cytokines and effector molecules of cytotoxic T lymphocytes in tuberculous pleural effusion","volume":"20","author":"CC Shu","year":"2015","journal-title":"Respirology"},{"issue":"6","key":"pone.0252714.ref014","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1007\/s00408-013-9512-2","article-title":"Combining clinical and analytical parameters improves prediction of malignant pleural effusion","volume":"191","author":"L Vald\u00e9s","year":"2013","journal-title":"Lung"},{"key":"pone.0252714.ref015","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1177\/001316446002000104","article-title":"A coefficient of agreement for nominal scales","volume":"20","author":"J Cohen","year":"1960","journal-title":"Educ Psychol Meas"},{"issue":"1","key":"pone.0252714.ref016","doi-asserted-by":"crossref","first-page":"159","DOI":"10.2307\/2529310","article-title":"The measurement of observer agreement for categorical data","volume":"33","author":"JR Landis","year":"1977","journal-title":"Biometrics"},{"issue":"8","key":"pone.0252714.ref017","first-page":"514","article-title":"Recommendations of the Spanish Working Group on Crohn\u2019s Disease and Ulcerative Colitis (GETECCU) on the utility of the determination of faecal calprotectin in inflammatory bowel disease","volume":"41","author":"J Guardiola","year":"2018","journal-title":"Gastroenterol Hepatol"},{"issue":"2","key":"pone.0252714.ref018","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.labcli.2016.03.003","article-title":"Gu\u00eda sobre las pruebas de laboratorio en el lugar de asistencia al paciente (POCT). Documento de la comisi\u00f3n de la SEQC","volume":"9","author":"P Oliver S\u00e1ez","year":"2016","journal-title":"Revista de Laboratorio Cl\u00ednico"},{"issue":"7\u20138","key":"pone.0252714.ref019","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1080\/10408363.2017.1399336","article-title":"Point-of-care testing (POCT) and evidence-based laboratory medicine (EBLM)\u2014does it leverage any advantage in clinical decision making?","volume":"54","author":"C Florkowski","year":"2017","journal-title":"Crit Rev Clin Lab Sci"},{"key":"pone.0252714.ref020","unstructured":"Quantum BlueR Calprotectin Normal Range Quantitative Lateral Flow Assay LF-CAL20 package insert (2010-11-10)."},{"key":"pone.0252714.ref021","unstructured":"Quantum BlueR Calprotectin High Range Quantitative Lateral Flow Assay LF-CHR25 package insert (2013-05-16)."},{"key":"pone.0252714.ref022","unstructured":"Quantum Blue R Calprotectin Extended Quantitative Lateral Flow Assay LF-CALE25 package insert (2014-01-27)."},{"key":"pone.0252714.ref023","unstructured":"Quantum BlueR sCAL Quantitative Lateral Flow Assay LF-MRP25 package insert (2016-11-23)."},{"issue":"4","key":"pone.0252714.ref024","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1515\/cclm-2012-0386","article-title":"Faecal calprotectin: comparative study of the Quantum Blue rapid test and an established ELISA method","volume":"51","author":"L Coorevits","year":"2013","journal-title":"Clin Chem Lab Med"},{"issue":"13","key":"pone.0252714.ref025","doi-asserted-by":"crossref","first-page":"2028","DOI":"10.3748\/wjg.v19.i13.2028","article-title":"Measurement of calprotectin in ascitic fluid to identify elevated polymorphonuclear cell count","volume":"19","author":"E Burri","year":"2013","journal-title":"World J Gastroenterol"},{"issue":"1","key":"pone.0252714.ref026","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1177\/2050640613518201","article-title":"Comparison of six different calprotectin assays for the assessment of inflammatory bowel disease","volume":"2","author":"D Labaere","year":"2014","journal-title":"United European Gastroenterol J"},{"issue":"4","key":"pone.0252714.ref027","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.1016\/j.arth.2017.11.006","article-title":"Synovial Calprotectin: An Inexpensive Biomarker to Exclude a Chronic Prosthetic Joint Infection","volume":"33","author":"M Wouthuyzen-Bakker","year":"2018","journal-title":"J Arthroplasty"},{"issue":"1","key":"pone.0252714.ref028","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1515\/cclm-2017-0041","article-title":"alpha-Defensin point-of-care test for diagnosis of prosthetic joint infections: neglected role of laboratory and clinical pathologists","volume":"56","author":"L Drago","year":"2017","journal-title":"Clin Chem Lab Med"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0252714","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,6,10]],"date-time":"2021-06-10T23:45:40Z","timestamp":1623368740000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0252714"}},"subtitle":[],"editor":[{"given":"Pal Bela","family":"Szecsi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,6,10]]},"references-count":28,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2021,6,10]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0252714","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,6,10]]}}}