Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2020 Aug:129:104539.
doi: 10.1016/j.jcv.2020.104539. Epub 2020 Jul 6.

Performance evaluation of Abbott ARCHITECT SARS-CoV-2 IgG immunoassay in comparison with indirect immunofluorescence and virus microneutralization test

Silvia Meschi  1 , Francesca Colavita  1 , Licia Bordi  1 , Giulia Matusali  1 , Daniele Lapa  1 , Alessandra Amendola  1 , Francesco Vairo  1 , Giuseppe Ippolito  1 , Maria Rosaria Capobianchi  2 , Concetta Castilletti  1 ; INMICovid-19 laboratory team  1
Affiliations
Comparative Study

Performance evaluation of Abbott ARCHITECT SARS-CoV-2 IgG immunoassay in comparison with indirect immunofluorescence and virus microneutralization test

Silvia Meschi et al. J Clin Virol. 2020 Aug.

Abstract

Background: Serological tests for anti-SARS-CoV-2 antibodies are becoming of great interest to determine seroprevalence in a given population, define previous exposure and identify highly reactive human donors for the generation of convalescent serum as therapeutic.

Objectives: We evaluated the diagnostic performance of the Abbott ARCHITECT SARS-CoV-2 IgG test, a fully automated indirect immunoassay that detects antibodies directed to a recombinant SARS-CoV-2 Nucleocapsid antigen.

Study design: Abbott ARCHITECT SARS-CoV-2 IgG immunoassay was compared to an indirect immunofluorescence assay (IFA) on sera from patients with COVID-19 collected at different days after symptoms onset or infected by other human coronaviruses. Comparison with neutralization test was also performed.

Results: After 7, 14 and >14 days after onset ARCHITECT was positive on 8.3 %; 61.9 % and 100 % of the tested samples compared to 58.3 %; 85.7 % and 100 % by IFA. The sensitivity was 72 % vs. IFA and 66.7 % vs. a real-time PCR, the specificity was 100 %. On 18 samples with neutralizing activity, 17 were positive by Abbott ARCHITECT SARS-CoV-2 IgG.

Conclusions: In our study, Abbott ARCHITECT SARS-CoV-2 IgG assay showed a satisfactory performance, with a very high specificity. IgG reactivity against SARSCoV-2 N antigen was detectable in all patients by two weeks after symptoms onset. In addition, concordance between this serological response and viral neutralization suggests that a strong humoral response may be predictive of a neutralization activity, regardless of the target antigens. This finding supports the use of this automated serological assay in diagnostic algorithm and public health intervention, especially for high loads of testing.

Keywords: CLIA; COVID-19; IgG; Immunofluorescence assay; SARS-CoV-2; Serological assay.

PubMed Disclaimer

Conflict of interest statement

Declaration of Competing Interest Abbott Diagnostics supplied the materials employed for the purposes of this study. In no way this contribution influenced the study design and the analysis of the results. No additional conflict of interest or other competing relationships exist.

Figures

Fig. 1
Fig. 1
Relative frequency of positivity by RT-PCR for SARS-CoV-2 RNA (PCR+, dashed line), IFA IgG (IFA+, dashed line) and Abbott ARCHITECT SARS-CoV-2 IgG (IgG+, dotted line) according to days after symptoms onset intervals.
Fig. 2
Fig. 2
Correlation between microneutralization titres (reciprocal of the dilution on the Y axis) and Abbott ARCHITECT IgG Index (X axis) on 18 samples from COVID-19 patients. The vertical line represents the ARCHITECT cutoff value.
See this image and copyright information in PMC

References

    1. Zhu N., Zhang D., Wang W., Li X., Yang B., Song J. A novel coronavirus from patients with pneumonia in China, 2019. N. Eng. J. Med. 2020;382:727–733. doi: 10.1056/NEJMoa2001017. - DOI - PMC - PubMed
    1. World Health Organization . 2020. (WHO) Rolling Updates on Coronavirus Disease (COVID-19) Outbreak Situation.https://www.who.int/emergencies/diseases/novel-coronavirus-2019
    1. Centers for Disease Control and Prevention (CDC) Interim Guidelines for COVID-19 Antibody Testing. https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests-g... accessed June 20th, 2020.
    1. Lippi G., Mattiuzzi C., Bovo C., Plebani M. Current laboratory diagnostics of coronavirus disease 2019 (COVID-19) Acta Biomed. 2020;91(2):137–145. doi: 10.12890/2020_001738. - DOI - PMC - PubMed
    1. Gronvall G., Connell N., Kobokovich A. 2020. Developing a National Strategy for Serology (Antibody Testing) in the United States Johns Hopkins Center for Health Security; 621 E. Pratt Street, Suite 210, Baltimore, MD 21202; April 22nd.

Publication types

MeSH terms