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
【저자키워드】 antibodies, SARS-CoV-2, coronavirus, serology, flow cytometry, 【초록키워드】 serological test, CLIA, viral infection, coronavirus, pandemic, Antibody Response, variant, diagnostic, viral infections, flow cytometry, ELISA, Spike protein, Laboratory, ACE-2, Spread, nucleic acid, sensitivity, specificity, Antibody responses, Viral, Serological tests, Serological assay, sera, SARS-CoV-2 spike protein, quantification, Quantitative, SARS-CoV-2-specific antibodies, specific antibodies, angiotensin, IgG and IgM, PCR-confirmed, Spike-specific antibody responses, IgM antibody, blueprint, early phase, specimen, patient sera, Zoonotic coronavirus, SARS-CoV-2-infected patients, while, spike-specific antibody response, Spike-specific antibody, approach, flow cytometric, robust, highest, detect, evaluated, provide, were used, adopted, expressing, 293T cell, 【제목키워드】 Antibody Response, Rapid, flow cytometric,