Comparison of the Elecsys® Anti-SARS-CoV-2 immunoassay with the EDI™ enzyme linked immunosorbent assays for the detection of SARS-CoV-2 antibodies in human plasma

Abstract

Background: Here, we report on a head-to-head comparison of the fully-automated Elecsys® Anti-SARS-CoV-2 immunoassay with the EDI TM enzyme linked immunosorbent assays (ELISA) for the detection of SARS-CoV-2 antibodies in human plasma. Methods: SARS-CoV-2 antibodies were measured with the Elecsys® assay and the EDI TM ELISAs (IgM and IgG) in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n = 104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. Results: In COVID-19 patients, the percentage of positive results rose with time from symptom onset, peaking to positivity rates after 15-22 days of 100% for the Elecsys® assay, of 94% for the EDI TM IgM-ELISA and of 100% for the EDI TM IgG ELISA. In the 104 blood samples, the agreement between positive/negative classifications of the Elecsys® assay and the EDI TM ELISAs (IgM or IgG) was 90%. The false positivity rates in the healthy blood donors and the ICU patients were < 1% for the Elecsys® assay and < 3% for the EDI TM ELISAs. Conclusions: Our results indicate a high sensitivity and specificity for the Elecsys® assay and an acceptable agreement with the EDI TM ELISAs.

Time‐dependent changes in the seroprevalence of COVID‐19 in asymptomatic liver disease outpatients in an area in Japan undergoing a second wave of COVID‐19

“…7 Additionally, Egger et al similarly revealed the high sensitivity (100%) and specificity (false positivity <1) of the Elecsys Anti-SARS-CoV-2 test using plasma samples. 6 Although rigorous differences between the results of the Elecsys Anti-SARS-CoV-2 assay using serum and plasma might not be sufficiently clarified in the manufacturer's instructions (of Elecsys Anti-SARS-CoV-2), both samples could be utilized for the test (https://diagnostics.roche. com/jp/ja/products/params/elecsys-anti-sars-cov-2.…”

“…html#north-america). Thus, although this point should be considered during interpretation, considering our results and recent reports, 6,7 we mainly focused on the evaluation of the time-dependent change in the seroprevalence of outpatients with liver disease, who were asymptomatic for COVID-19, by the results of the Elecsys Anti-SARS-CoV-2 immunoassay.…”

“…Additionally, in the early stage of infection with SARS-CoV-2, the sensitivity of the Elecsys Anti-SARS-CoV-2 assay was not high. 6 Because this study did not include the patients who underwent real-time polymerase chain reaction for SARS-CoV-2, the sensitivity of the assays and true SARS-CoV-2 infection case could not be directly analyzed. Thus, this point should be considered when interpreting the results.…”

“…The Elecsys assay utilizes a modified double-antigen sandwich immunoassay targeting recombinant SARS-CoV-2 nucleocapsid proteins. 6 The test can detect different types of SARS-CoV-2 antibodies, primarily IgG, and a cut-off index (signal sample / cut-off)≥1.0 indicates a positive diagnosis.…”

Evaluation of the SARS-CoV-2-IgG response in outpatients by five commercial immunoassays

“…SARS-CoV-2-IgG were detected second to third weeks after onset of symptoms in up to 100% of hospitalized patients by use of various commercial immunoassays [ 2 ], [ 7 ], [ 8 ], [ 9 ], [ 10 ], [ 11 ], [ 12 ]. It has been shown that SARS-CoV-2-IgG titers were higher in critical cases compared to less critical patients and that severe ill patients seroconverted earlier than mild cases [ 7 ], [ 13 ], [ 14 ].…”