{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T10:57:08Z","timestamp":1791889028233,"version":"4.3.4"},"reference-count":37,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2022,7,28]],"date-time":"2022-07-28T00:00:00Z","timestamp":1658966400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Shenzhen YHLO Biotech Co."}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>The diagnostic of SARS-CoV-2 infection relies on reverse transcriptase polymerase chain reactions (RT-PCRs) performed on nasopharyngeal (NP) swabs. Nevertheless, false-negative results can be obtained with inadequate sampling procedures, making the use of other biological matrices worthy of investigation. This study aims to evaluate the kinetics of serum N antigens in severe and non-severe patients and compare the clinical performance of serum antigenic assays with NP RT-PCR. Ninety patients were included in the study and monitored for several days. Disease severity was determined according to the WHO clinical progression scale. Serum N antigen levels were measured with a chemiluminescent assay (CLIA) and the Single Molecular Array (Simoa) assay. Viremia thresholds for severity were determined and proposed. In severe patients, the peak antigen response was observed 7 days after the onset of symptoms, followed by a decline. No real peak response was observed in non-severe patients. Severity thresholds for the Simoa and the CLIA provided positive likelihood ratios of 30.0 and 10.9 for the timeframe between day 2 and day 14, respectively. Sensitive detection of N antigens in serum may thus provide a valuable new marker for COVID-19 diagnosis and evaluation of disease severity. When assessed during the first 2 weeks since the onset of symptoms, it may help in identifying patients at risk of developing severe COVID-19 to optimize better intensive care utilization.<\/jats:p>","DOI":"10.3390\/v14081653","type":"journal-article","created":{"date-parts":[[2022,7,29]],"date-time":"2022-07-29T01:41:16Z","timestamp":1659058876000},"page":"1653","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["Serum SARS-CoV-2 Antigens for the Determination of COVID-19 Severity"],"prefix":"10.3390","volume":"14","author":[{"given":"Julien","family":"Favresse","sequence":"first","affiliation":[{"name":"Department of Laboratory Medicine, Clinique St-Luc Bouge, 5004 Namur, Belgium"},{"name":"Department of Pharmacy, Namur Research Institute for LIfe Sciences, University of Namur, 5000 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2043-3455","authenticated-orcid":false,"given":"Jean-Louis","family":"Bayart","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Clinique St-Pierre Ottignies, 1340 Ottignies-Louvain-la-Neuve, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Clara","family":"David","sequence":"additional","affiliation":[{"name":"Qualiblood s.a., 5000 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4151-9760","authenticated-orcid":false,"given":"Constant","family":"Gillot","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, Namur Research Institute for LIfe Sciences, University of Namur, 5000 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gr\u00e9goire","family":"Wie\u00ebrs","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Clinique Saint-Pierre Ottignies, 1340 Ottignies-Louvain-la-Neuve, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gatien","family":"Roussel","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Clinique St-Pierre Ottignies, 1340 Ottignies-Louvain-la-Neuve, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guillaume","family":"Sondag","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Clinique St-Luc Bouge, 5004 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marc","family":"Elsen","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Clinique St-Luc Bouge, 5004 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christine","family":"Eucher","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Clinique St-Luc Bouge, 5004 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Michel","family":"Dogn\u00e9","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, Namur Research Institute for LIfe Sciences, University of Namur, 5000 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7644-5298","authenticated-orcid":false,"given":"Jonathan","family":"Douxfils","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, Namur Research Institute for LIfe Sciences, University of Namur, 5000 Namur, Belgium"},{"name":"Qualiblood s.a., 5000 Namur, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1037","DOI":"10.1515\/cclm-2020-0722","article-title":"Molecular, serological, and biochemical diagnosis and monitoring of COVID-19: IFCC taskforce evaluation of the latest evidence","volume":"58","author":"Bohn","year":"2020","journal-title":"Clin. 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