Differences of SARS-CoV-2 serological test performance between hospitalized and outpatient COVID-19 cases.
Clin Chim Acta
; 511: 352-359, 2020 Dec.
Article
in English
| MEDLINE | ID: covidwho-909320
ABSTRACT
BACKGROUND:
Serological severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays differ in the target antigen specificity, e.g. of antibodies directed against the viral spike or the nucleocapsid protein, and in the spectrum of detected immunoglobulins. The aim of the study was to evaluate the performance of two different routinely used immunoassays in hospitalized and outpatient COVID-19 cases.METHODS:
The test characteristics of commercially available spike1 protein-based serological assays (Euroimmun, EI-assays), determining IgA or IgG and nucleocapsid-based assays (Virotech, VT-assays) determining IgA, IgM or IgG were compared in 139 controls and 116 hospitalized and outpatient COVID-19 cases.RESULTS:
Hospitalized COVID-19 patients (n = 51; 115 samples) showed significantly higher concentrations of antibodies against SARS-CoV-2 and differed from outpatient cases (n = 65) by higher age, higher disease severity scores and earlier follow up blood sampling. Sensitivity of the two IgG assays was comparable in hospitalized patients tested ≥ 14 days (EI-assay 88%, CI95% 67.6-99.9; VT-assay 96%, CI95% 77.7-99.8). In outpatient COVID-19 cases sensitivity was significantly lower in the VT-assay (86.2%, CI95% 74.8-93.1) compared with the EI-assay (98.5%, CI95% 90.6-99.9). Assays for IgA and IgM demonstrated a lack of specificity or sensitivity.CONCLUSIONS:
Our results indicate that SARS-CoV-2 serological assays may need to be optimized to produce reliable results in outpatient COVID-19 cases who are low or even asymptomatic. Assays for IgA and IgM have limited diagnostic performance and do not prove an additional value for population-based screening approaches.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Ambulatory Care
/
COVID-19 Serological Testing
/
SARS-CoV-2
/
COVID-19
/
Hospitalization
Type of study:
Cohort study
/
Diagnostic study
/
Experimental Studies
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Observational study
/
Prognostic study
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
/
Middle aged
/
Young adult
Language:
English
Journal:
Clin Chim Acta
Year:
2020
Document Type:
Article
Affiliation country:
J.cca.2020.10.035
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