Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Oct 9;15(10):e0240502.
doi: 10.1371/journal.pone.0240502. eCollection 2020.

Antibody responses to SARS-CoV-2 in patients with differing severities of coronavirus disease 2019

Ekasit Kowitdamrong  1   2 , Thanyawee Puthanakit  3   4 , Watsamon Jantarabenjakul  3   4   5 , Eakachai Prompetchara  6   7 , Pintip Suchartlikitwong  1   4 , Opass Putcharoen  5   8 , Nattiya Hirankarn  1   9
Affiliations

Antibody responses to SARS-CoV-2 in patients with differing severities of coronavirus disease 2019

Ekasit Kowitdamrong et al. PLoS One. .

Abstract

Background: A greater understanding of the antibody response to SARS-CoV-2 in an infected population is important for the development of a vaccination.

Aim: To investigate SARS-CoV-2 IgA and IgG antibodies in Thai patients with differing severities of COVID-19.

Methods: Plasma from the following patient groups was examined: 118 adult patients with confirmed SARS-CoV-2 infections, 49 patients under investigation (without confirmed infections), 20 patients with other respiratory infections, and 102 healthy control patients. Anti-SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA) from EUROIMMUN was performed to assess for IgA and IgG antibodies. The optical density (OD) ratio cutoff for a positive result was 1.1 for IgA and 0.8 for IgG. Additionally, the association of the antibody response with both the severity of disease and the date after onset of symptoms was analyzed.

Results: A total of 289 participants were enrolled and 384 samples analyzed from March 10 to May 31, 2020. Patients were categorized, based on their clinical manifestations, as mild (n = 59), moderate (n = 27), or severe (n = 32). The overall sensitivity of IgA and IgG from the samples collected after day 7 of the symptoms was 87.9% (95% CI: 79.8-93.6) and 84.8% (95% CI: 76.2-91.3), respectively. Compared to the mild group, the severe group had significantly higher levels of spike 1 (S1) antigen-specific IgA and IgG. All patients in the moderate and severe groups had S1-specific IgG, while 20% of the patients in the mild group did not have any IgG detected after two weeks after the onset of symptoms. Interestingly, in the severe group, the SARS-CoV-2 IgG level was significantly higher in males than females (p = 0.003).

Conclusion: The serological test for SARS-CoV-2 has a high sensitivity more than two weeks after the onset of illness. Additionally, the serological response differs among patients based on sex as well as the severity of infection.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1
Antibody levels based on disease severity: A) ELISA IgA OD ratio, B) ELISA IgG OD ratio.
Fig 2
Fig 2
Average antibody levels among COVID-19 patients with different disease severity by date of illness: A) IgA OD ratio and B) IgG OD ratio.
Fig 3
Fig 3
The correlation between antibody level and age in the severe group: A) Age VS ELISA IgA OD ratio, B) Age VS ELISA IgG OD ratio.
Fig 4
Fig 4
The relationship between antibody levels and sex in the severe group: A) Sex VS ELISA IgA OD ratio, B) Sex VS ELISA IgG OD ratio.
See this image and copyright information in PMC

References

    1. Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395(10223):497–506. 10.1016/S0140-6736(20)30183-5 - DOI - PMC - PubMed
    1. Wang C, Horby PW, Hayden FG, Gao GF. A novel coronavirus outbreak of global health concern. Lancet. 2020;395(10223):470–3. 10.1016/S0140-6736(20)30185-9 - DOI - PMC - PubMed
    1. Worldometers.info. Dover, Delaware, U.S.A [updated 30th July, 2020. Available from: https://www.worldometers.info/coronavirus/.
    1. Okada P, Buathong R, Phuygun S, Thanadachakul T, Parnmen S, Wongboot W, et al. Early transmission patterns of coronavirus disease 2019 (COVID-19) in travellers from Wuhan to Thailand, January 2020. Euro Surveill. 2020;25(8). - PMC - PubMed
    1. Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DK, et al. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020;25(3). - PMC - PubMed

Publication types

MeSH terms