Erytra Blood Group Analyser and Kode Technology testing of SARS-CoV-2 antibodies among convalescent patients and vaccinated individuals

Abstract

Surveillance of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires tests to monitor antibody formation and prevalence. We detected SARS-CoV-2 antibodies using red cells coated by Kode technology with short peptides derived from the SARS-CoV-2 spike protein. Such modified red cells, called C19-kodecytes, can be used as reagent cells in any manual or automated column agglutination assay. We investigated the presence of SARS-CoV-2 antibodies in 130 samples from COVID-19 convalescent plasma donors using standard manual technique, two FDA authorized ELISA assays and a virus neutralisation assay. The sensitivity of the C19-kodecyte assay was 88%, comparable to the anti-SP and anti-NCP ELISAs (86% and 83%) and the virus neutralisation assay (88%). The specificity of the C19-kodecyte assay was 90% (anti-SP 100% and anti-NCP 97%). Likewise, 231 samples from 73 vaccinated individuals were tested with an automated analyser and we monitored the appearance and persistence of SARS-CoV-2 antibodies. The C19-kodecyte assay is a robust tool for SARS-CoV-2 antibody detection. Automated blood group analyser use enables large-scale SARS-CoV-2 antibody testing for vaccination monitoring in population surveys.

COVID-19 Antibody Detection and Assay Performance Using Red Cell Agglutination

“…The Ortho Total assay turned positive in a vaccinated individual on day 14 after the vaccination and the C19-kodecyte assay on day 28 when the second dose was scheduled (data not shown). Additional results were reported separately ( 27 ).…”

Simulated RBC antibody identification training panels created using SARS‐CoV‐2 kodecytes and immune plasma

“…1 Secondarily acquired antigens, for example Lewis, 6 Chido/Rodgers, 7 some drugs, 8 and Kode Technology constructs once attached to the membrane behave like intrinsic RBC antigens and react accordingly when the corresponding antibody is present. [1][2][3][5][6][7]9 Normally reagent cells in an antibody screening or identification panel contain a range of different RBCs selected as a set for their complementary antigenic profiles. However, here with SASID panels, kodecytes and unmodified cells were organized as reagent cell panels (screening and identification) to mimic antigenic variations (see exemplars, Figures 2 & S1-S8).…”

“… 1 Secondarily acquired antigens, for example Lewis, 6 Chido/Rodgers, 7 some drugs, 8 and Kode Technology constructs once attached to the membrane behave like intrinsic RBC antigens and react accordingly when the corresponding antibody is present. 1 , 2 , 3 , 5 , 6 , 7 , 9 …”

“…Currently, the majority of individuals globally have antibodies to SARS‐CoV‐2. We used this phenomenon to evaluate the ability of Kode technology to controllably attach specific amounts of SARS‐CoV‐2 viral antigen 1 , 2 , 3 onto the RBC membrane and then used immune plasma samples from vaccinated or COVID‐19 convalescent individuals to create an antigen–antibody pairing suitable for serologic training requirements.…”