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 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 demonstrates 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.

SARS-CoV-2 infection of African green monkeys results in mild respiratory disease discernible by PET/CT imaging and shedding of infectious virus from both respiratory and gastrointestinal tracts

“…Notably, there was simultaneous seroconversion of both IgM and IgG. This contradicts the classic immunology paradigm of IgM proceeding IgG in response to antigen exposure, however this mirrors precisely what occurs in COVID-19 patients [20][21][22][23], further validating the utility of this AGM model. All animals seroconverted in the second week post exposure and those that were exposed via the mucosal route had higher overall titers than those that received the virus via the aerosol route.…”

Meta-analysis of diagnostic performance of serology tests for COVID-19: impact of assay design and post-symptom-onset intervals

“…Previously, NAATs were the recommended gold standard for COVID-19 diagnosis by the WHO, while antigen tests were not recommended due to insufficient performance data 57 , 58 . Another concern raised by the WHO regarding serology tests was the relatively long antibody window, with seroconversion occurring during the second week after symptom onset 52 . At present, antibody detection was only suggested for epidemiological research or disease surveillance 5 , 9 , 59 , 60 .…”

Physical Activity, Health-Related Quality of Life, and Stress among the Chinese Adult Population during the COVID-19 Pandemic

“…A local outbreak of pneumonia from an initially unknown cause was first detected in Wuhan, Hubei province China around December 2019 [1]. It rapidly affected over 20 provinces in China within a matter of weeks [2].…”