Evaluation of a New Spike (S)-Protein-Based Commercial Immunoassay for the Detection of Anti-SARS-CoV-2 IgG

Kirsten Alexandra Eberhardt; Felix Dewald; Eva Heger; Lutz Gieselmann; Kanika Vanshylla; Maike Wirtz; Franziska Kleipass; Wibke Johannis; Philipp Schommers; Henning Gruell; Karl August Brensing; Roman-Ulrich Müller; Max Augustin; Clara Lehmann; Manuel Koch; Florian Klein; Veronica Di Cristanziano

doi:10.3390/microorganisms9040733

Evaluation of a New Spike (S)-Protein-Based Commercial Immunoassay for the Detection of Anti-SARS-CoV-2 IgG

Microorganisms. 2021 Mar 31;9(4):733. doi: 10.3390/microorganisms9040733.

Authors

Kirsten Alexandra Eberhardt^{1

2}, Felix Dewald^{3

4}, Eva Heger³, Lutz Gieselmann³, Kanika Vanshylla^{3

4}, Maike Wirtz³, Franziska Kleipass³, Wibke Johannis⁵, Philipp Schommers^{3

6

7}, Henning Gruell^{3

7}, Karl August Brensing⁸, Roman-Ulrich Müller^{4

9

10}, Max Augustin⁶, Clara Lehmann^{4

6

7}, Manuel Koch^{4

11}, Florian Klein^{3

4

7}, Veronica Di Cristanziano^{3

4}

Affiliations

¹ Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.
² Institute for Transfusion Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.
³ Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany.
⁴ Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany.
⁵ Institute for Clinical Chemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany.
⁶ Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany.
⁷ German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50931 Cologne, Germany.
⁸ Nierenzentrum Bonn, Godesberger Allee 26, 53175 Bonn, Germany.
⁹ Department II of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany.
¹⁰ Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, CECAD, University of Cologne, 50931 Cologne, Germany.
¹¹ Institute for Experimental Dentistry and Oral Musculoskeletal Biology, and Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany.

Abstract

Background: The investigation of the antibody response to SARS-CoV-2 represents a key aspect in facing the COVID-19 pandemic. In the present study, we compared the new Immundiagnostik IDK® anti-SARS-CoV-2 S1 IgG assay with four widely-used commercial serological assays for the detection of antibodies targeting S (spike) and NC (nucleocapsid) proteins. Methods: Serum samples were taken from an unbiased group of convalescent patients and from a negative control group. Sample were simultaneously analyzed by the new Immundiagnostik IDK^® anti-SARS-CoV-2 S1 IgG assay, by the DiaSorin LIAISON^® SARS-CoV-2 S1/S2 IgG assay, and by the Euroimmun anti-SARS-CoV-2 S1 IgG ELISA. Antibodies binding NC were detected by the Abbott SARS-CoV-2 IgG assay and by the pan-immunoglobulin immunoassay Roche Elecsys^® anti-SARS-CoV-2. Moreover, we investigated samples of a group of COVID-19 convalescent subjects that were primarily tested S1 IgG non-reactive. Samples were also tested by live virus and pseudovirus neutralization tests. Results: Overall, the IDK® anti-SARS-CoV-2 S1 IgG assay showed the highest sensitivity among the evaluated spike (S) protein-based assays. Additionally, the Immundiagnostik assay correlated well with serum-neutralizing activity. Conclusions: The novel IDK^® anti-SARS-CoV-2 S1 IgG assay showed high sensitivity and specificity, representing a valid option for use in the routine diagnostic.

Keywords: COVID-19; antibody; coronavirus; humoral response; neutralization; non-responder; pandemic; protection; sensitivity; titer.

Abstract

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