Laboratory-Based SARS-CoV-2 Receptor Binding Domain Serologic Assays Perform with Equivalent Sensitivity and Specificity to Commercial FDA-EUA Approved Tests

Mary Nehring; Sierra Pugh; Tina Dihle; Emily Gallichotte; Terry Nett; Eric Weber; Christie Mayo; Lori Lynn; Greg Ebel; Bailey K Fosdick; Sue VandeWoude

doi:10.3390/v15010106

Laboratory-Based SARS-CoV-2 Receptor Binding Domain Serologic Assays Perform with Equivalent Sensitivity and Specificity to Commercial FDA-EUA Approved Tests

Viruses. 2022 Dec 30;15(1):106. doi: 10.3390/v15010106.

Authors

Affiliations

¹ Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
² Department of Statistics, Colorado State University, Fort Collins, CO 80523, USA.
³ Health and Medical Center Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
⁴ Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
⁵ Department of Biostatistics and Informatics, Colorado School of Public Health, Denver, CO 80206, USA.

Abstract

During early phases of the SARS-CoV-2 epidemic, many research laboratories repurposed their efforts towards developing diagnostic testing that could aid public health surveillance while commercial and public diagnostic laboratories developed capacity and validated large scale testing methods. Simultaneously, the rush to produce point-of-care and diagnostic facility testing resulted in FDA Emergency Use Authorization with scarce and poorly validated clinical samples. Here, we review serologic test results from 186 serum samples collected in early phases of the pandemic (May 2020) from skilled nursing facilities tested with six laboratory-based and two commercially available assays. Serum neutralization titers were used to set cut-off values using positive to negative ratio (P/N) analysis to account for batch effects. We found that laboratory-based receptor binding domain (RBD) binding assays had equivalent or superior sensitivity and specificity compared to commercially available tests. We also determined seroconversion rate and compared with qPCR outcomes. Our work suggests that research laboratory assays can contribute reliable surveillance information and should be considered important adjuncts to commercial laboratory testing facilities during early phases of disease outbreaks.

Keywords: SARS-CoV-2; laboratory diagnostics; serology; surveillance.

Publication types

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

MeSH terms

Antibodies, Viral
COVID-19 Testing
COVID-19* / diagnosis
Clinical Laboratory Techniques / methods
Humans
SARS-CoV-2*
Sensitivity and Specificity
Serologic Tests / methods

Substances

Antibodies, Viral

Grants and funding

This research was funded by Boettcher Foundation and funds donated by the Colorado State University Colleges of Health and Human Sciences, Veterinary Medicine and Biomedical Sciences, Natural Sciences, and Walter Scott, Jr. College of Engineering, the Colorado State University Columbine Health Systems Center for Healthy Aging, and the CSU One Health Institute.