Rapid and accurate agglutination-based testing for SARS-CoV-2 antibodies

Sally Esmail; Michael J Knauer; Husam Abdoh; Courtney Voss; Benjamin Chin-Yee; Peter Stogios; Almagul Seitova; Ashley Hutchinson; Farhad Yusifov; Tatiana Skarina; Elena Evdokimova; Suzanne Ackloo; Lori Lowes; Benjamin D Hedley; Vipin Bhayana; Ian Chin-Yee; Shawn S-C Li

doi:10.1016/j.crmeth.2021.100011

Rapid and accurate agglutination-based testing for SARS-CoV-2 antibodies

Cell Rep Methods. 2021 Jun 21;1(2):100011. doi: 10.1016/j.crmeth.2021.100011. Epub 2021 May 12.

Authors

Sally Esmail¹, Michael J Knauer², Husam Abdoh², Courtney Voss¹, Benjamin Chin-Yee³, Peter Stogios⁴, Almagul Seitova⁵, Ashley Hutchinson⁵, Farhad Yusifov⁵, Tatiana Skarina⁴, Elena Evdokimova⁴, Suzanne Ackloo⁵, Lori Lowes², Benjamin D Hedley², Vipin Bhayana², Ian Chin-Yee², Shawn S-C Li¹

Affiliations

¹ Departments of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON N6G 2V4, Canada.
² Department of Pathology and Laboratory Medicine, Western University and London Health Sciences Centre, 800 Commissioners Road East, London, ON N6A 5W9, Canada.
³ Divison of Hematology, Western University and London Health Sciences Centre, 800 Commissioners Road East, London, ON N6A 5W9, Canada.
⁴ Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada.
⁵ Structural Genomics Consortium, University of Toronto, 101 College Street, MaRS South Tower, Suite 700, Toronto, ON M5G 1L7, Canada.

Abstract

We have developed a rapid, accurate, and cost-effective serologic test for SARS-CoV-2 virus, which caused the COVID-19 pandemic, on the basis of antibody-dependent agglutination of antigen-coated latex particles. When validated using plasma samples that are positive or negative for SARS-CoV-2, the agglutination assay detected antibodies against the receptor-binding domain of the spike (S-RBD) or the nucleocapsid protein of SARS-CoV-2 with 100% specificity and ∼98% sensitivity. Furthermore, we found that the strength of the S-RBD antibody response measured by the agglutination assay correlated with the efficiency of the plasma in blocking RBD binding to the angiotensin-converting enzyme 2 in a surrogate neutralization assay, suggesting that the agglutination assay might be used to identify individuals with virus-neutralizing antibodies. Intriguingly, we found that >92% of patients had detectable antibodies on the day of a positive viral RNA test, suggesting that the agglutination antibody test might complement RNA testing for the diagnosis of SARS-CoV-2 infection.

Keywords: COVID-19; SARS-CoV-2; agglutination assay; antibody test; neutralizing antibody; nucleocapsid; rapid testing; serology; spike.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Agglutination
Antibodies, Viral
COVID-19* / diagnosis
Humans
Pandemics
SARS-CoV-2*

Substances

Antibodies, Viral