%0 Journal Article %J Diagn Microbiol Infect Dis %D 2022 %T Importance of anti-SARS-CoV-2 assay antigenic composition as revealed by the results of the Belgian external quality assessment (EQA) scheme. %A Alena Moerman %A Kris Vernelen %A Bernard China %A Arnaud Capron %A Dorien Van Den Bossche %A Joachim Mariën %A Ariën, Kevin K %A Van Acker, Jos %A Delforge, Marie-Luce %A Marijke Reynders %A An Boel %A Melissa Depypere %A Natasja Van Gasse %A Sara Vijgen %A Jonathan Brauner %A Barbara Dujardin %A Padalko, Elizaveta %K Adult %K Antibodies, Viral %K Antigens, Viral %K Belgium %K Coronavirus Nucleocapsid Proteins %K COVID-19 %K COVID-19 Serological Testing %K Diagnostic Tests, Routine %K Enzyme-Linked Immunosorbent Assay %K Humans %K Immunoglobulin A %K Immunoglobulin G %K Immunoglobulin M %K Male %K Phosphoproteins %K SARS-CoV-2 %K Sensitivity and Specificity %K Spike Glycoprotein, Coronavirus %X

We report on sample IS/17575 since it generated highly divergent results in the Belgian SARS-CoV-2 serology external quality assessment scheme. Sample IS/17575 was serum originating from a 30 years old male patient. 124 diagnostic laboratories analysed this sample. A total of 168 results was returned (including 5 doubles). Overall, 38 were positive. All tests against S1 were positive except the Euroimmun IgG ELISA and the Ortho clinical Diagnostics VITROS IgG CLIA. All tests against S1/S2 (Liaison, Diasorin) resulted in a signal above cutoff. Assays against RBD, mostly generate a negative result. An exception are the Wantai SARS-CoV-2 ELISA's. All tests targeting N protein were negative. The survey shows, when >6 months post-infection, assays targeting at least S1, and preferably S1 combined with S2, are the most sensitive. This finding accentuates the necessity of external quality assessment schedules and importance of antigenic composition of serologic SARS-CoV-2 assays.

%B Diagn Microbiol Infect Dis %V 102 %8 2022 Feb %G eng %N 2 %R 10.1016/j.diagmicrobio.2021.115561