Longitudinal Monitoring of SARS-CoV-2 IgM and IgG Seropositivity to Detect COVID-19.

Abstract

BACKGROUND:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a novel beta-coronavirus that has recently emerged as the cause of the 2019 coronavirus pandemic (COVID-19). Polymerase chain reaction (PCR) based tests are optimal and recommended for the diagnosis of an acute SARS-CoV-2 infection. Serology tests for viral antibodies provide an important tool to diagnose previous exposure to the virus. Here we evaluate the analytical performance parameters of the Diazyme SARS-CoV-2 IgM/IgG serology assays and describe the kinetics of IgM and IgG seroconversion observed in patients with PCR-confirmed COVID-19 who were admitted to our hospital.

METHODS:

We validated the performance of the Diazyme assay in 235 presumed SARS-CoV-2 negative subjects to determine specificity. Subsequently, we evaluated the SARS-CoV-2 IgM and IgG seroconversion of 54 PCR-confirmed COVID-19 patients and determined sensitivity of the assay at three different timeframes.

RESULT:

Sensitivity and specificity for detecting seropositivity at ≥15 days following a positive SARS-CoV-2 PCR result, was 100.0% and 98.7% when assaying for the panel of IgM and IgG. The median time to seropositivity observed for a reactive IgM and IgG result from the date of a positive PCR was 5 days (IQR: 2.75-9 days) and 4 days (IQR: 2.75-6.75 days), respectively.

CONCLUSIONS:

Our data demonstrate that the Diazyme IgM/IgG assays are suited for the purpose of detecting SARS-CoV-2 IgG and IgM in patients with suspected SARS-CoV-2 infections. For the first time, we report longitudinal data showing the evolution of seroconversion for both IgG and IgM in a cohort of acutely ill patients in the United States. We also demonstrate a low false positive rate in patients who were presumed to be disease free.

• Authors: Raymond T Suhandynata, Melissa A Hoffman, Michael J Kelner, Ronald W McLawhon, Sharon L Reed, Robert L Fitzgerald
• Journal: The journal of applied laboratory medicine (J Appl Lab Med) Vol. 5 Issue 5 Pg. 908-920 (09 01 2020) ISSN: 2576-9456 [Print] England
• PMID: 32428207 (Publication Type: Journal Article)
• Copyright: © American Association for Clinical Chemistry 2020. All rights reserved. For permissions, please email: [email protected].

Chemical References

• Antibodies, Viral
• Immunoglobulin G
• Immunoglobulin M

Topics

• Antibodies, Viral (blood, isolation & purification)
• Betacoronavirus (immunology, isolation & purification)
• COVID-19
• COVID-19 Testing
• Clinical Laboratory Techniques (methods)
• Coronavirus Infections (diagnosis, immunology, virology)
• Female
• Humans
• Immunoglobulin G (blood, isolation & purification)
• Immunoglobulin M (blood, isolation & purification)
• Male
• Middle Aged
• Monitoring, Immunologic (methods)
• Pandemics
• Pneumonia, Viral (diagnosis, immunology, virology)
• SARS-CoV-2
• Sensitivity and Specificity
• Seroconversion