Quantitation of serum NtAb titers in plasma from convalescent COVID-19 individuals is recommended for optimal selection of specimens for passive transfer therapies; the FDA recommends the use of plasma with NtAb50 levels ?1/160 [22]. and a value ?10% compared to previous sampling point), descendant (any decrease), fluctuating, or constant. Results Patients characteristics All 51 individuals presented with pneumonia and imaging or laboratory findings compatible with COVID-19 and were hospitalized in either the pneumology ward (n?=?27) or the intensive care unit (ICU; n?=?24). As demonstrated in Table ?Table1,1, most patients (69%) experienced one or more comorbidities and displayed high serum levels of several pro-inflammatory biomarkers at the time of serological testing. Four ICU individuals eventually died. Specificity of NtAb and SARS-CoV-2 IgG immunoassays Out of the 20 control sera, none of them returned positive results by any of the immunoassays used in the study. Therefore, the specificity of CLIA and the NtAb assays was 100% (95% CI, 83.9C100%). Agreement between NtAb and SARS-CoV-2 IgG immunoassays results Qualitative results returned by immunoassays were evaluated either considering the entire dataset or grouping sera according to the time of sampling after the onset of symptoms (, 0.84; 95% CI, 0.63C1), followed by those of the Euroimmun SARS-CoV-2 IgG ELISA (, 0.52; 0.52; 95% CI, 0.22C0.81), LIAISON SARS-CoV-2 S1/S2 IgG (, 0.5; 95% CI, 0.2C0.78), and MAGLUMI 2019-nCoV IgG (0.4; 95% CI, 0.2C0.77). The same pattern was observed when sera collected either
Positive (all sera)8376757783Negative (all sera)71415137Positive/
Positive/positive75/30/4574/29/4575/30/4582/36/46Negative/negative5/3/26/3/36/3/36/3/3Positive/negative8/7/19/8/18/7/11/1/0Negative/positive2/1/11/1/01/1/01/1/0 Open in a separate windows NtAb, neutralizing antibodies A total of 90 sera were included, of which 41 were collected TZ9 spike protein) and four commercial SARS-CoV-2 IgG immunoassays for the analysis of COVID-19
All seraa92.2 (86.7C97.8)84.4 (77.0C91.9)83.3 (75.6C91.0)85.6 (78.3C92.8)92.2 (86.7C97.8)Sera collected ETV7 after the onset of symptomsa90.2 (77.5C96.1)75.6 (60.7C86.2)73.2 (58.1C84,3)75.6 (60.7C86.2)90.2 (77.5C96.1)Sera collected ?15?days since the onset of symptomsa93.9 (83.5C97.9)91.8 (88.8C96.8)91.8 (88,8C96.8)93.9 (83,5C97.9)93.9 (83.5C97.9) Open in a separate window aA total of 90 sera were included, of which 41 were collected