Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

Abstract PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing..

Medienart:

Preprint

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

bioRxiv.org - (2021) vom: 15. Jan. Zur Gesamtaufnahme - year:2021

Sprache:

Englisch

Beteiligte Personen:

Yokoyama, Rin [VerfasserIn]
Kurano, Makoto [VerfasserIn]
Morita, Yoshifumi [VerfasserIn]
Shimura, Takuya [VerfasserIn]
Nakano, Yuki [VerfasserIn]
Qian, Chungen [VerfasserIn]
Xia, Fuzhen [VerfasserIn]
He, Fan [VerfasserIn]
Kishi, Yoshiro [VerfasserIn]
Okada, Jun [VerfasserIn]
Yoshikawa, Naoyuki [VerfasserIn]
Nagura, Yutaka [VerfasserIn]
Okazaki, Hitoshi [VerfasserIn]
Moriya, Kyoji [VerfasserIn]
Seto, Yasuyuki [VerfasserIn]
Kodama, Tatsuhiko [VerfasserIn]
Yatomi, Yutaka [VerfasserIn]

Links:

Volltext [kostenfrei]

doi:

10.1101/2020.07.16.20155796

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

XBI018365205