Objectives During the COVID-19 pandemic, SARS-CoV-2 antibody testing has been suggested for (1) screening populations for disease prevalence, (2) diagnostics, and (3) guiding therapeutic applications. Here, we conducted a detailed clinical evaluation of four Anti-SARS-CoV-2 immunoassays in samples from acutely ill COVID-19 patients and in two negative cohorts. Methods 443 serum specimens from serial sampling of 29 COVID-19 patients were used to determine clinical sensitivities. Patients were stratified for the presence of acute respiratory distress syndrome (ARDS). Individual serum specimens from a pre-COVID-19 cohort of 238 healthy subjects and from a PCR-negative clinical cohort of 257 patients were used to determine clinical specificities. All samples were measured side-by-side with the Anti-SARS-CoV-2-ELISA (IgG), Anti-SARS-CoV-2-ELISA (IgA) and Anti-SARS-CoV-2-NCP-ELISA (IgG) (Euroimmun AG, Lübeck, Germany) and the Elecsys Anti-SARS-CoV-2 ECLIA (Roche Diagnostics International, Rotkreuz, Switzerland). Results Median seroconversion occurred earlier in ARDS patients (8–9 days) than in non-ARDS patients (11–17 days), except for EUR N-IgG. Rates of positivity and mean signal ratios in the ARDS group were significantly higher than in the non-ARDS group. Sensitivities between the four tested immunoassays were equivalent. In the set of negative samples, the specificity of the Anti-SARS-CoV-2-ELISA (IgA) was lower (93.9%) compared to all other assays (≥98.8%) and the specificity of Anti-SARS-CoV-2-NCP-ELISA (IgG) was lower (98.8%) than that of Elecsys Anti-SARS-CoV-2 (100%). Conclusions Serial sampling in COVID-19 patients revealed earlier seroconversion and higher signal ratios of SARS-CoV-2 antibodies as a potential risk marker for the development of ARDS, suggesting a utility for antibody testing in acutely diseased patients.
【초록키워드】 IgG, Respiratory distress syndrome, ARDS, Antibody testing, acute respiratory distress syndrome, COVID-19 pandemic, anti-SARS-CoV-2, diagnostics, ELISA, Population, immunoassay, serum, specificity, Cohort, Seroconversion, SARS-CoV-2 antibodies, Disease prevalence, SARS-CoV-2 antibody, clinical evaluation, Germany, IgA, therapeutic, Patient, utility, Switzerland, patients, SARS-CoV-2 antibody testing, acute respiratory distress, marker, COVID-19 patient, respiratory distress, risk marker, individual, potential risk, specimen, syndrome, cohorts, ARDS patients, sensitivities, side, Roche Diagnostics, Specificities, PCR-negative, Elecsys, Lubeck, objective, Result, tested, occurred, Rate, conducted, were used, determine, suggested, significantly higher, healthy subject, were measured, stratified, ARDS patient, Elecsy, 【제목키워드】 immunoassay, Seroconversion, SARS-CoV-2 antibody, COVID-19 patient,