Performance Characteristics of Four High-Throughput Immunoassays for Detection of IgG Antibodies against SARS-CoV-2

J Clin Microbiol. 2020 Jul 23;58(8):e01243-20. doi: 10.1128/JCM.01243-20. Print 2020 Jul 23.

Abstract

The role of serologic testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in both the clinical and public health settings, will continue to evolve as we gain increasing insight into our immune response to the virus. Here, we evaluated four high-throughput serologic tests for detection of anti-SARS-CoV-2 IgG antibodies, from Abbott Laboratories (Abbott Park, IL), Epitope Diagnostics, Inc. (San Diego, CA), Euroimmun (Lubeck, Germany), and Ortho-Clinical Diagnostics (Rochester, NY), using a panel of serially collected serum samples (n = 224) from 56 patients with confirmed coronavirus disease 2019 (COVID-19), healthy donor sera from 2018, and a cross-reactivity serum panel collected in early 2020. The sensitivities of the Abbott, Epitope, Euroimmun, and Ortho-Clinical IgG assays in convalescent-phase serum samples collected more than 14 days post-symptom onset or post-initial positive reverse transcriptase PCR (RT-PCR) result were 92.9% (78/84), 88.1% (74/84), 97.6% (82/84), and 98.8% (83/84), respectively. Among unique convalescent patients, sensitivities of the Abbott, Epitope, Euroimmun, and Ortho-Clinical anti-SARS-CoV-2 IgG assays were 97.3% (36/37), 73% (27/37), 94.6% (35/37), and 97.3% (36/37), respectively. Overall assay specificity/positive predictive values based on a 5% prevalence rate were 99.6%/92.8%, 99.6%/90.6%, 98.0%/71.2%, and 99.6%/92.5%, respectively, for the Abbott, Epitope, Euroimmun, and Ortho-Clinical IgG assays. In conclusion, we show high sensitivity in convalescent-phase sera and high specificity for the Abbott, Euroimmun, and Ortho-Clinical anti-SARS-CoV-2 IgG assays. With the unprecedented influx of commercially available serologic tests for detection of antibodies against SARS-CoV-2, it remains imperative that laboratories thoroughly evaluate such assays for accuracy prior to implementation.

Keywords: COVID-19; IgG antibodies; SARS-CoV-2; antibodies; serology.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Viral / blood*
  • Betacoronavirus / immunology*
  • Clinical Laboratory Techniques / methods*
  • Coronavirus Infections / diagnosis*
  • Female
  • Germany
  • High-Throughput Screening Assays*
  • Humans
  • Immunoglobulin G / blood*
  • Male
  • Middle Aged
  • Pandemics
  • Pneumonia, Viral / diagnosis*
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Young Adult

Substances

  • Antibodies, Viral
  • Immunoglobulin G

Supplementary concepts

  • COVID-19
  • COVID-19 diagnostic testing
  • severe acute respiratory syndrome coronavirus 2