Commercially available immunoassays have been developed for sensitive and specific detection of antibodies against SARS-CoV-2. While high sensitivity has been reported in hospitalized COVID-19 patients, little is known about the performance of the assays in ambulatory patients. Therefore, we evaluated the SARS-CoV-2-IgG response in 51 SASR-CoV-2-PCR-confirmed outpatients with five commercial immunoassays. The sensitivity in serum samples, collected at a median of 24 days after onset of symptoms, detected by the Anti-SARS-CoV-2-ELISA IgG (Euroimmun), EDI™ Novel Coronavirus COVID-19 IgG ELISA (Epitope Diagnostics), Liaison ® SARS-CoV-2 S1/S2 IgG (Diasorin), SARS-CoV-2 IgG on the Architect™ i2000 (Abbott), and Elecsys ® Anti-SARS-CoV-2 (IgM/IgA/IgG) on the cobas™ e801 (Roche) was 84.3%, 78.4%, 74.5%, 86.3%, and 88.2%, respectively. The sensitivity in serum samples, collected >20 days after onset of symptoms, varied between 75.0% and 90.0%, and in samples, collected at least 28 days after onset of symptoms, did not increase, except in the Anti-SARS-CoV-2-ELISA IgG by Euroimmun (90.0%). There was not an obvious association between the type of the antigen (N versus S protein) and the overall sensitivity of the assays. Our results show significant individual differences of the IgG response against SARS-CoV-2, additionally confirmed in three patients with follow-up serum samples and seven asymptomatic but PCR-positive contact persons. In conclusion, our study shows that commercially available immunoassays detect SARS-CoV-2-IgG or total antibodies in outpatients with a satisfying sensitivity, but lower than that reported for hospitalized patients. In asymptomatic persons the SARS-CoV-2-IgG response may even be absent in a relevant percentage of persons.
【저자키워드】 COVID-19, serology, Antibody Response, immunoassay, SARS-CoV-2-IgG, 【초록키워드】 SARS-CoV-2, IgG, S protein, antibody, hospitalized patients, Antigen, immunoassays, sensitivity, Asymptomatic, Patient, Follow-up, novel, total antibody, IgG ELISA, Roche, SARS-CoV-2 IgG, association, Outpatient, Contact, Abbott, IgG response, hospitalized COVID-19 patients, serum samples, ambulatory patients, PCR-positive, S1/S2, while, serum sample, FIVE, Seven, detect, collected, reported, assays, evaluated, median, onset of symptoms, Elecsy, 【제목키워드】 Outpatient, FIVE, commercial immunoassay,