Scientific Reports (Apr 2021)

Evaluation of 11 SARS-CoV-2 antibody tests by using samples from patients with defined IgG antibody titers

  • Nina Lagerqvist,
  • Kimia T. Maleki,
  • Jenny Verner-Carlsson,
  • Mikaela Olausson,
  • Joakim Dillner,
  • Julia Wigren Byström,
  • Tor Monsen,
  • Mattias Forsell,
  • Jenny Eriksson,
  • Gordana Bogdanovic,
  • Sandra Muschiol,
  • Joel Ljunggren,
  • Johanna Repo,
  • Torbjörn Kjerstadius,
  • Shaman Muradrasoli,
  • Mia Brytting,
  • Åsa Szekely Björndal,
  • Thomas Åkerlund,
  • Charlotta Nilsson,
  • Jonas Klingström

DOI
https://doi.org/10.1038/s41598-021-87289-6
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 8

Abstract

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Abstract We evaluated the performance of 11 SARS-CoV-2 antibody tests using a reference set of heat-inactivated samples from 278 unexposed persons and 258 COVID-19 patients, some of whom contributed serial samples. The reference set included samples with a variation in SARS-CoV-2 IgG antibody titers, as determined by an in-house immunofluorescence assay (IFA). The five evaluated rapid diagnostic tests had a specificity of 99.0% and a sensitivity that ranged from 56.3 to 81.6% and decreased with low IFA IgG titers. The specificity was > 99% for five out of six platform-based tests, and when assessed using samples collected ≥ 22 days after symptom onset, two assays had a sensitivity of > 96%. These two assays also detected samples with low IFA titers more frequently than the other assays. In conclusion, the evaluated antibody tests showed a heterogeneity in their performances and only a few tests performed well with samples having low IFA IgG titers, an important aspect for diagnostics and epidemiological investigations.