Abstract Background Primary diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is based on detection of virus RNA in nasopharyngeal swab samples. In addition, analysis of humoral immunity against SARS-CoV-2 has an important role in viral diagnostics and seroprevalence estimates. Methods We developed and optimized an enzyme immunoassays (EIA) using SARS-CoV-2 nucleoprotein (N), S1 and receptor binding domain (RBD) of the viral spike protein, and N proteins from SARS, Middle East respiratory syndrome (MERS), and 4 low-pathogenic human CoVs. Neutralizing antibody activity was compared with SARS-CoV-2 IgG, IgA, and IgM EIA results. Results The sensitivity of EIA for detecting immune response in COVID-19 patients (n = 101) was 77% in the acute phase and 100% in the convalescent phase of SARS-CoV-2 infection when N and RBD were used as antigens in IgG and IgA specific EIAs. SARS-CoV-2 infection significantly increased humoral immune responses against the 229E and NL63 N proteins. S1 and RBD-based EIA results had a strong correlation with microneutralization test results. Conclusions The data indicate a combination of SARS-CoV-2 S1 or RBD and N proteins and analysis of IgG and IgA immunoglobulin classes in sera provide an excellent basis for specific and sensitive serological diagnostics of COVID-19. A combination of SARS-CoV-2 N and S antigens and measurement of both IgG and IgA increases the sensitivity of serological diagnostics of COVID-19 and provides a basis for accurate estimation of seroprevalence.
【저자키워드】 COVID-19, antibodies, SARS-CoV-2, Neutralizing antibodies, serology, respiratory infection, enzyme immunoassay, coronavirus proteins, 【초록키워드】 severe acute respiratory syndrome coronavirus 2, IgG, IgM, coronavirus, immune response, antibody, SARS-COV-2 infection, Seroprevalence, Infection, MERS, severe acute respiratory syndrome Coronavirus, diagnostics, Spike protein, Receptor binding domain, Antigen, Nasopharyngeal swab, immunoassay, sensitivity, Humoral immunity, Viral, Immunoglobulin, RBD, IgA, immune responses, sera, N protein, antigens, NL63, humoral immune response, respiratory, correlation, estimates, humoral immune responses, serological, SARS-CoV-2 IgG, S antigen, COVID-19 patients, Microneutralization test, 229E, Nasopharyngeal swab samples, Combination, Analysis, Middle East respiratory syndrome, COVID-19 patient, Middle East, test results, enzyme immunoassays, primary diagnosis, viral spike protein, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, acute phase, convalescent phase, enzyme, syndrome, CoVs, human CoVs, SARS-CoV-2 nucleoprotein, N proteins, virus RNA, SARS-CoV-2 S1, significantly increased, Result, addition, provide, increase, were used, in viral, 【제목키워드】 IgG, IgA, measurement,