PreprintCited by 159SARS-CoV-2 detection and testingSARS-CoV-2 and COVID-19 ResearchCOVID-19 Clinical Research Studies

A preliminary study on serological assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 238 admitted hospital patients

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Liu, Lei, Liu, Wanbing, Zheng, Yaqiong, Jiang, Xiaojing, Kou, Guomei, Ding, Jinya, Wang, Qiongshu, Huang, Qianchuan +17 more·2020·Microbes and Infection

Preprint — published as 10.1016/j.micinf.2020.05.008

Abstract

Background: The outbreak of the recently emerged novel corona virus disease 2019 (COVID-19) poses a challenge for public health laboratories. We aimed to evaluate the diagnostic value of serological assay for SARS-CoV-2. Methods: A newly-developed ELISA assay for IgM and IgG antibodies against N protein of SARS-CoV-2 were used to screen the serums of 238 admitted hospital patients with confirmed or suspected SARS-CoV-2 infection from February 6 to February 14, 2020. SARS-CoV-2 RNA was detected by real time RT-PCR on pharyngeal swab specimens. Findings: Of the 238 patients, 194 (81.5%) were detected to be antibody (IgM and/or IgG) positive, which was significantly higher than the positive rate of viral RNA (64.3%). There was no difference in the positive rate of antibody between the confirmed patients (83.0%, 127/153) and the suspected patients (78.8%, 67/85) whose nucleic acid tests were negative. After the patients were defined to the different stages of disease based on the day when the test samples were collected, the analysis results showed that the antibody positive rates were very low in the first five days after initial onset of symptoms, and then rapidly increased as the disease progressed. After 10 days, the antibody positive rates jumped to above 80% from less than 50%. On the contrary, the positive rates of viral RNA kept above 60% in the first 11 days after initial onset of symptoms, and then rapidly decreased. In addition, half of the suspected patients with symptoms for 6-10 days were detected to be antibody positive. Interpretation: The suspected patients were most likely infected by SARS-CoV-2. Before the 11th day after initial onset of symptoms, nucleic acid test is important for confirmation of viral infection. The combination of serological assay can greatly improve the diagnostic efficacy. After that, the diagnosis for viral infection should be majorly dependent on serological assay.

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  • The serological profile of PiCoVacc-immunized mice closely matches that of recovered COVID-19 patients.

    “which closely matches the serological profile of the blood of recovered COVID-19 patients (Fig. 2, A and B) (11).”

    From Development of an inactivated vaccine candidate for SARS-CoV-2 (2020) · cites this paper as [11]

    The Performance and validation section (p. 10) reports SARS-CoV-2 IgM and IgG results in admitted patients, providing evidence about human antibody responses. It does not identify those patients as recovered or compare their serological profile with PiCoVacc-immunized mice. (LLM, conf=0.82)

    Experimental — accuracy not yet measured
  • Previous studies have shown that N-specific IgG is largely abundant in serum of COVID-19 patients and serves as a clinical diagnostic marker.

    “previous studies have shown that the N-specific IgG is largely abundant in the serum of COVID-19 patients and serves as one of the clinical diagnostic markers (11).”

    From Development of an inactivated vaccine candidate for SARS-CoV-2 (2020) · cites this paper as [11]

    The Performance and validation section (p. 10) reports that an N-protein-based assay detected IgM and/or IgG in 81.5% of the 238 patients, supporting the use of these antibodies as diagnostic markers. It does not establish that N-specific IgG alone was abundant in most patients; the Discussion (p. 13) also says antibody detection depends on disease stage. (LLM, conf=0.84)

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  1. [17]17. Guan M, Chen HY, Foo SY, et al. Recombinant protein-based enzyme-linked immunosorbent assay and immunochromatographic tests for detection of immunoglobulin G antibodies to severe acute Clin Diagn Lab Immunol respiratory syndrome (SARS) coronavirus in SARS patients. 2020; published online Jan 29. Doi: It is made available under a CC-BY-NC-ND 4.0 International license . is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) medRxiv preprint doi: https://doi.org/10.1101/2020.03.06.20031856; this version posted March 8, 2020. The copyright holder for this preprint 343 344 345 346 347 348 349 350 351 352 353 354 2004;11(2):287-91.

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Authors
Liu, L., Liu, W., Zheng, Y., Jiang, X., Kou, G., Ding, J., Wang, Q., Huang, Q., Ding, Y., Ni, W., Wu, W., Tang, S., Tan, L., Hu, Z., Xu, W., Zhang, Y., Zhang, B., Tang, Z., Zhang, X., Li, H., Rao, Z., Jiang, H., Ren, X., Wang, S., & Zheng, S.
Affiliations
  • General Hospital of Central Theater Command (CN)
  • Chinese Academy of Sciences (CN)
Corresponding author
  • Wang, Shengdian
  • Zheng, Shangen
Venue
Microbes and Infection
Publisher
openRxiv
Published
2020-03-08
Volume
22
Issue
4-5
Pages
206-211
ISSN
1286-4579 (ISSN-L)
OpenAlex
W3025809437
Cited by
159
References
18
Citations by year
2026: 1 · 2025: 3 · 2024: 6 · 2023: 8 · 2022: 17 · 2021: 47 · 2020: 77
FWCI
4.73
Type
journal article
Language
en
Open access
Locations
  • Microbes and Infection (publishedVersion)
  • medRxiv (acceptedVersion, cc-by-nc-nd)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Natural Science Foundation of China (81801984, 81830003)
  • Chinese Academy of Sciences
  • China Postdoctoral Science Foundation (2019M664008)
  • National Key Research and Development Program of China (2019YFC130030)
Topics
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 detection and testing
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
Keywords
SARS-CoV-2, COVID-19 pandemic, serological diagnosis, ELISA, IgM and IgG antibodies, viral RNA detection, RT-PCR, diagnostic timing, hospitalized patients
MeSH terms
Betacoronavirus, COVID-19, SARS-CoV-2, Adult, Aged, Antibodies, Viral, Enzyme-Linked Immunosorbent Assay, Female, Humans, Immunoglobulin G, Immunoglobulin M, Inpatients, Male, Middle Aged, Pneumonia, Viral, RNA, Viral, Serologic Tests, Coronavirus Infections, Pandemics

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