Four point-of-care lateral flow immunoassays for diagnosis of COVID-19 and for assessing dynamics of antibody responses to SARS-CoV-2

J Infect. 2020 Sep;81(3):435-442. doi: 10.1016/j.jinf.2020.06.023. Epub 2020 Jun 15.

Abstract

Objectives: We aimed to evaluate the role of rapid serological tests in the management of coronavirus disease 2019 (COVID-19) patients.

Methods: This retrospective study enrolled 16 real-time reverse transcription polymerase chain reaction-confirmed symptomatic patients with COVID-19 and 58 COVID-19 negative patients at a medical center in Taiwan over a 3-month period. Serial serum samples were collected and tested for antibody response using four point-of-care (POC) lateral flow immunoassays (LFIA) (ALLTEST 2019-nCoV IgG/IgM Rapid Test, Dynamiker 2019-nCoV IgG/IgM Rapid Test, ASK COVID-19 IgG/IgM Rapid Test, and Wondfo SARS-CoV-2 Antibody Test). Time-dependent detection sensitivity and timeliness of seroconversion were determined and compared between the four POC rapid tests.

Results: The overall sensitivity and specificity of the four tests for detecting anti-SARS-CoV-2 antibodies after 3 weeks of symptom onset were 100% and 100%, respectively. There was no significant difference between the rapid tests used for detection of IgM and IgG separately and those used for detection of combined total antibody (mainly IgM/IgG). There was no significant difference between the four POC rapid tests in terms of time required for determining seroconversion of COVID-19. Patients with COVID-19 with pneumonia demonstrated shorter seroconversion time than those without pneumonia.

Conclusion: Though the POC antibody rapid tests based on LFIA showed reliable performance in the detection of SARS-CoV-2-specific antibodies, the results of these tests should be interpreted and applied appropriately in the context of antibody dynamic of COVID-19 infection. COVID-19 patients complicated with pneumonia exhibited earlier anti-SARS-CoV-2 antibody response than COVID-19 patients without pneumonia.

Keywords: Antibody response; COVID-19 pandemic; Immunochromatographic assay; Lateral flow method; Rapid test.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Antibodies, Viral / blood*
  • Betacoronavirus / immunology*
  • COVID-19
  • Case-Control Studies
  • Coronavirus Infections / diagnosis*
  • Coronavirus Infections / immunology
  • Female
  • Humans
  • Immunoassay / methods*
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Male
  • Middle Aged
  • Pandemics
  • Pneumonia, Viral / diagnosis*
  • Pneumonia, Viral / immunology
  • Point-of-Care Systems*
  • Retrospective Studies
  • SARS-CoV-2
  • Sensitivity and Specificity
  • Serologic Tests / methods*
  • Virus Shedding

Substances

  • Antibodies, Viral
  • Immunoglobulin G
  • Immunoglobulin M