Journal Article

Rapid response flow cytometric assay for the detection of antibody responses to SARS-CoV-2

Steininger Philipp, Tenbusch Matthias, Winkler, Thomas H, Kremer, Andreas E, Hübner, Julian, Hoffmann, Markus, Birkholz Torsten, Irrgang Pascal, Ensser Armin, Überla Klaus, Lapuente, Dennis, Korn, Klaus, Maier, Clara, Neipel Frank, Sophia, Peter Antonia, Ziegler, Katharina

2021

Overview

SARS-CoV-2 has emerged as a previously unknown zoonotic coronavirus that spread worldwide causing a serious pandemic. While reliable nucleic acid–based diagnostic assays were rapidly available, only a limited number of validated serological assays were available in the early phase of the pandemic. Here, we evaluated a novel flow cytometric approach to assess spike-specific antibody responses.HEK 293T cells expressing SARS-CoV-2 spike protein in its natural confirmation on the surface were used to detect specific IgG and IgM antibody responses in patient sera by flow cytometry. A soluble angiotensin-converting-enzyme 2 (ACE-2) variant was developed as external standard to quantify spike-specific antibody responses on different assay platforms. Analyses of 201 pre-COVID-19 sera proved a high assay specificity in comparison to commercially available CLIA and ELISA systems, while also revealing the highest sensitivity in specimens from PCR-confirmed SARS-CoV-2-infected patients. The external standard allowed robust quantification of antibody responses among different assay platforms. In conclusion, our newly established flow cytometric assay allows sensitive and quantitative detection of SARS-CoV-2-specific antibodies, which can be easily adopted in different laboratories and does not rely on external supply of assay kits. The flow cytometric assay also provides a blueprint for rapid development of serological tests to other emerging viral infections

• Publisher: Springer Nature B.V
• Subject: Angiotensin / Antibodies / Assaying / Coronaviruses / COVID-19 / Enzyme-linked immunosorbent assay / Flow cytometry / Immunoglobulin G / Immunoglobulin M / Nucleic acids / Pandemics / Peptidyl-dipeptidase A / Serological tests / Serology / Severe acute respiratory syndrome coronavirus 2 / Spike protein / Viral diseases