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Serum-IgG responses to SARS-CoV-2 after mild and severe COVID-19 infection and analysis of IgG non-responders

Marklund, Emelie ; Leach, Susannah ; Axelsson, Hannes ; Nystrom, Kristina ; Norder, Heléne ; Bemark, Mats LU orcid ; Angeletti, Davide ; Lundgren, Anna ; Nilsson, Staffan and Andersson, Lars Magnus , et al. (2020) In PLoS ONE 15(10). p.1-11
Abstract

Background To accurately interpret COVID-19 seroprevalence surveys, knowledge of serum-IgG responses to SARS-CoV-2 with a better understanding of patients who do not seroconvert, is imperative. This study aimed to describe serum-IgG responses to SARS-CoV-2 in a cohort of patients with both severe and mild COVID-19, including extended studies of patients who remained seronegative more than 90 days post symptom onset. Methods SARS-CoV-2-specific IgG antibody levels were quantified using two clinically validated and widely used commercial serological assays (Architect, Abbott Laboratories and iFlash 1800, YHLO), detecting antibodies against the spike and nucleocapsid proteins. Results Forty-seven patients (mean age 49 years, 38% female)... (More)

Background To accurately interpret COVID-19 seroprevalence surveys, knowledge of serum-IgG responses to SARS-CoV-2 with a better understanding of patients who do not seroconvert, is imperative. This study aimed to describe serum-IgG responses to SARS-CoV-2 in a cohort of patients with both severe and mild COVID-19, including extended studies of patients who remained seronegative more than 90 days post symptom onset. Methods SARS-CoV-2-specific IgG antibody levels were quantified using two clinically validated and widely used commercial serological assays (Architect, Abbott Laboratories and iFlash 1800, YHLO), detecting antibodies against the spike and nucleocapsid proteins. Results Forty-seven patients (mean age 49 years, 38% female) were included. All (15/15) patients with severe symptoms and 29/32 (90.6%) patients with mild symptoms of COVID-19 developed SARS-CoV-2-specific IgG antibodies in serum. Time to seroconversion was significantly shorter (median 11 vs. 22 days, P = 0.04) in patients with severe compared to mild symptoms. Of the three patients without detectable IgG-responses after >90 days, all had detectable virus-neutralizing antibodies and in two, spike-protein receptor binding domainspecific IgG was detected with an in-house assay. Antibody titers were preserved during follow-up and all patients who seroconverted, irrespective of the severity of symptoms, still had detectable IgG levels >75 days post symptom onset. Conclusions Patients with severe COVID-19 both seroconvert earlier and develop higher concentrations of SARS-CoV-2-specific IgG than patients with mild symptoms. Of those patients who not develop detectable IgG antibodies, all have detectable virus-neutralizing antibodies, suggesting immunity. Our results showing that not all COVID-19 patients develop detectable IgG using two validated commercial clinical methods, even over time, are vital for the interpretation of COVID-19 seroprevalence surveys.

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publishing date
type
Contribution to journal
publication status
published
in
PLoS ONE
volume
15
issue
10
article number
e0241104
pages
1 - 11
publisher
Public Library of Science (PLoS)
external identifiers
  • pmid:33085715
  • scopus:85094167493
ISSN
1932-6203
DOI
10.1371/journal.pone.0241104
language
English
LU publication?
no
additional info
Publisher Copyright: © 2020 Marklund et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
id
2918698b-d4ab-45bb-b909-40110ac1e716
date added to LUP
2023-12-06 16:39:53
date last changed
2024-04-19 11:17:07
@article{2918698b-d4ab-45bb-b909-40110ac1e716,
  abstract     = {{<p>Background To accurately interpret COVID-19 seroprevalence surveys, knowledge of serum-IgG responses to SARS-CoV-2 with a better understanding of patients who do not seroconvert, is imperative. This study aimed to describe serum-IgG responses to SARS-CoV-2 in a cohort of patients with both severe and mild COVID-19, including extended studies of patients who remained seronegative more than 90 days post symptom onset. Methods SARS-CoV-2-specific IgG antibody levels were quantified using two clinically validated and widely used commercial serological assays (Architect, Abbott Laboratories and iFlash 1800, YHLO), detecting antibodies against the spike and nucleocapsid proteins. Results Forty-seven patients (mean age 49 years, 38% female) were included. All (15/15) patients with severe symptoms and 29/32 (90.6%) patients with mild symptoms of COVID-19 developed SARS-CoV-2-specific IgG antibodies in serum. Time to seroconversion was significantly shorter (median 11 vs. 22 days, P = 0.04) in patients with severe compared to mild symptoms. Of the three patients without detectable IgG-responses after &gt;90 days, all had detectable virus-neutralizing antibodies and in two, spike-protein receptor binding domainspecific IgG was detected with an in-house assay. Antibody titers were preserved during follow-up and all patients who seroconverted, irrespective of the severity of symptoms, still had detectable IgG levels &gt;75 days post symptom onset. Conclusions Patients with severe COVID-19 both seroconvert earlier and develop higher concentrations of SARS-CoV-2-specific IgG than patients with mild symptoms. Of those patients who not develop detectable IgG antibodies, all have detectable virus-neutralizing antibodies, suggesting immunity. Our results showing that not all COVID-19 patients develop detectable IgG using two validated commercial clinical methods, even over time, are vital for the interpretation of COVID-19 seroprevalence surveys.</p>}},
  author       = {{Marklund, Emelie and Leach, Susannah and Axelsson, Hannes and Nystrom, Kristina and Norder, Heléne and Bemark, Mats and Angeletti, Davide and Lundgren, Anna and Nilsson, Staffan and Andersson, Lars Magnus and Yilmaz, Aylin and Lindh, Magnus and Liljeqvist, JanÅke and Gisslen, Magnus}},
  issn         = {{1932-6203}},
  language     = {{eng}},
  number       = {{10}},
  pages        = {{1--11}},
  publisher    = {{Public Library of Science (PLoS)}},
  series       = {{PLoS ONE}},
  title        = {{Serum-IgG responses to SARS-CoV-2 after mild and severe COVID-19 infection and analysis of IgG non-responders}},
  url          = {{http://dx.doi.org/10.1371/journal.pone.0241104}},
  doi          = {{10.1371/journal.pone.0241104}},
  volume       = {{15}},
  year         = {{2020}},
}