Abstract
BACKGROUND: The COVID-19 pandemic is having a major global impact, and the resultant response in the development of new diagnostics is unprecedented. The detection of antibodies against SARS-CoV-2 has a role in managing the pandemic. We evaluated the feasibility of using SARS-CoV-2 peptide Kode Technology modified red cells (C19-kodecytes) to develop an assay compatible with existing routine serologic platforms. STUDY DESIGN AND METHODS: A panel of eight unique red cells modified using Kode Technology function-spacer-lipid constructs and bearing short SARS-CoV-2 peptides was developed (C19-kodecyte assay). Kodecytes were tested against undiluted expected antibody negative and positive plasma samples in manual tube and three column agglutination platforms. Parallel analysis with the same peptides in solid phase by enzyme immunoassays was performed. Evaluation samples included >120 expected negative blood donor samples and > 140 COVID-19 convalescent plasma samples, with independent serologic analysis from two centres. RESULTS: Specificity (reaction rate against expected negative samples) in three different column agglutionation (CAT) platforms against novel C19-kodecytes was >91%, which correlated with published literature. Sensitivity (reaction rate against expected positive convalescent, PCR confirmed samples) ranged from 82% to 97%, compared to 77% with the Abbott Architect SARS-CoV-2 IgG assay. Manual tube serology was less sensitive than CAT. Enzyme immuno assay results with some Kode Technology constructs also had high sensitivity. CONCLUSIONS: C19-kodecytes are viable for use as serologic reagent red cells for the detection of SARS-CoV-2 antibody with routine blood antibody screening equipment.
