Temporal Course of SARS-CoV-2 Antibody Positivity in Patients with COVID-19 following the First Clinical Presentation

Table 1

Employed tests for determination of anti-SARS-CoV-2 antibodies. ELISA = enzyme-linked immunosorbent assay; Ig = total immunoglobulin; N = nucleocapsid antigen; S1 = spike protein S1 subunit: S1/S2 = spike protein S1/S2 subunits; CV = coefficient of variation. DSX is an ELISA analyzer (Dynex Technologies, Denkendorf, Germany).

Test acronym	Measurement principle	Test name	Manufacturer	Analyzer	Isotype	Target antigen	Cut-off	CV (%)
CMIA	Chemiluminescent microparticle immunoassay	SARS-CoV-2 IgG	Abbott Diagnostics, Baar, Switzerland	Architect i2000	IgG	N	≥1.4	3.6
ECLIA	Electrochemiluminescence assay	Elecsys® Anti-SARS-CoV-2	Roche Diagnostics, Rotkreuz, Switzerland	COBAS 6000	Total Ig	N	>1	2.7
LIA	Luminescence immunoassay	LIAISON® SARS-CoV-2 S1/S2 IgG	Diasorin, Luzern, Switzerland	Liaison	IgG	S1/S2	>12	5.4
EI IgG	ELISA	EUROIMMUN Anti-SARS-CoV-2 ELISA IgG (EI IgG)	Euroimmun, Luzern, Switzerland	DSX	IgG	S1	≥1.1	3.6
EI IgA	ELISA	EUROIMMUN Anti-SARS-CoV-2 ELISA IgG (EI IgA)	Euroimmun, Luzern, Switzerland	DSX	IgA	S1	≥1.1	4.6
EDI IgG	ELISA	EDI™ Novel Coronavirus COVID-19 IgG	Epitope Diagnostics, Inc., San Diego, USA	DSX	IgG	N	Manufacturer specific	11.2
EDI IgM	ELISA	EDI™ Novel Coronavirus COVID-19 IgM	Epitope Diagnostics, Inc., San Diego, USA	DSX	IgM	N	Manufacturer specific	9.7
LFIA	Lateral flow immunoassay	SGTi-flex COVID-19 IgM/IgG	Sugentech Inc., Daejeon, South Korea	N/A	IgG/IgM	N	Qualitative reading	N/A