Clinical Validation and Performance Evaluation of the Automated Vitros Total Anti–SARS-CoV-2 Antibodies Assay for Screening of Serostatus in COVID-19

• Published in: American Journal of Clinical Pathology Vol. 154; no. 6; pp. 742 - 747
• Main Authors: Garnett, Emily, Jung, Joanna, Tam, Estella, Rajapakshe, Deepthi, Cheney, Stephen, Brown, Cameron, Cao, Jing, Muldrew, Kenneth, Singh, Ila, Versalovic, James, Devaraj, Sridevi
• Format: Journal Article Web Resource
• Language: English
• Published: US Oxford University Press 01.12.2020
• Subjects: Antibodies; Antibodies, Viral - blood; Betacoronavirus; Clinical Laboratory Techniques - methods; Coronaviridae; Coronavirus Infections - diagnosis; Coronaviruses; COVID-19; COVID-19 Testing; Cross-reactivity; Humans; Immunoassay - methods; Jaundice; Laboratories; Original; Pandemics; Pneumonia, Viral - diagnosis; Polymerase chain reaction; Reverse transcription; SARS-CoV-2; Sensitivity and Specificity; Seroconversion; Serologic Tests; Severe acute respiratory syndrome coronavirus 2; IgG; alidation; Serology; Coronavirus; SARS CoV-2 antibody; IgM
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1093/ajcp/aqaa157

Abstract Objectives Evaluation of serostatus against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as an important tool in identification of exposure to coronavirus disease 2019 (COVID-19). We report on the validation of the Vitros Anti–SARS-CoV-2 Total (CoV2T) assay for qualitative serologic testing of SARS-CoV-2 antibodies. Methods We performed validation studies according to Commission of Office Laboratories Accreditation guidelines, using samples previously tested for SARS-CoV-2 by reverse transcription–polymerase chain reaction (RT-PCR). We evaluated precision, analytical interferences, and cross-reactivity with other viral infections; evaluated concordance with molecular and other serologic testing; and evaluated seroconversion. Results The Vitros CoV2T assay exhibited acceptable precision and did not exhibit cross-reactivity with other acute respiratory virus infections. The CoV2T assay exhibited 100% negative predictive agreement (56/56) and 71% positive predictive agreement (56/79) with RT-PCR across all patient samples and was concordant with other serologic assays. Concordance with RT-PCR was 97% more than 7 days after symptom onset. The CoV2T assay was robust to icterus and lipemia but had interference from significant hemolysis. Conclusions The Vitros CoV2T assay was successfully validated in our laboratory. We anticipate it will be a useful tool in screening for exposure to SARS-CoV-2; however, the use of the CoV2T and other serologic assays in the clinical management of patients with COVID-19 is unknown and must be evaluated in future studies.