Low-volume antibody assays can be used to track SARS-CoV-2 infection rates in settings where active testing for virus is limited and remote sampling is optimal. We developed 12 ELISAs detecting total or antibody isotypes to SARS-CoV-2 nucleocapsid, spike protein or its receptor binding domain (RBD), 3 anti-RBD isotype specific luciferase immunoprecipitation system (LIPS) assays and a novel Spike-RBD bridging LIPS total-antibody assay. We utilized pre-pandemic (n=984) and confirmed/suspected recent COVID-19 sera taken pre-vaccination rollout in 2020 (n=269). Assays measuring total antibody discriminated best between pre-pandemic and COVID-19 sera and were selected for diagnostic evaluation. In the blind evaluation, two of these assays (Spike Pan ELISA and Spike-RBD Bridging LIPS assay) demonstrated >97% specificity and >92% sensitivity for samples from COVID-19 patients taken >21 days post symptom onset or PCR test. These assays offered better sensitivity for the detection of COVID-19 cases than a commercial assay which requires 100-fold larger serum volumes. This study demonstrates that low-volume in-house antibody assays can provide good diagnostic performance, and highlights the importance of using well-characterized samples and controls for all stages of assay development and evaluation. These cost-effective assays may be particularly useful for seroprevalence studies in low and middle-income countries.
Development and evaluation of low-volume tests to detect and characterize antibodies to SARS-CoV-2 / Halliday, Alice; Long, Anna E; Baum, Holly E; Thomas, Amy C; Shelley, Kathryn L; Oliver, Elizabeth; Gupta, Kapil; Francis, Ore; Williamson, Maia Kavanagh; Di Bartolo, Natalie; Randell, Matthew J; Ben-Khoud, Yassin; Kelland, Ilana; Mortimer, Georgina; Ball, Olivia; Plumptre, Charlie; Chandler, Kyla; Obst, Ulrike; Secchi, Massimiliano; Piemonti, Lorenzo; Lampasona, Vito; Smith, Joyce; Gregorova, Michaela; Knezevic, Lea; Metz, Jane; Barr, Rachael; Morales-Aza, Begonia; Oliver, Jennifer; Collingwood, Lucy; Hitchings, Benjamin; Ring, Susan; Wooldridge, Linda; Rivino, Laura; Timpson, Nicholas; Mckernon, Jorgen; Muir, Peter; Hamilton, Fergus; Arnold, David; Woolfson, Derek N; Goenka, Anu; Davidson, Andrew D; Toye, Ashley M; Berger, Imre; Bailey, Mick; Gillespie, Kathleen M; Williams, Alistair J K; Finn, Adam. - In: FRONTIERS IN IMMUNOLOGY. - ISSN 1664-3224. - 13:(2022), p. 968317. [10.3389/fimmu.2022.968317]
Development and evaluation of low-volume tests to detect and characterize antibodies to SARS-CoV-2
Piemonti, Lorenzo;
2022-01-01
Abstract
Low-volume antibody assays can be used to track SARS-CoV-2 infection rates in settings where active testing for virus is limited and remote sampling is optimal. We developed 12 ELISAs detecting total or antibody isotypes to SARS-CoV-2 nucleocapsid, spike protein or its receptor binding domain (RBD), 3 anti-RBD isotype specific luciferase immunoprecipitation system (LIPS) assays and a novel Spike-RBD bridging LIPS total-antibody assay. We utilized pre-pandemic (n=984) and confirmed/suspected recent COVID-19 sera taken pre-vaccination rollout in 2020 (n=269). Assays measuring total antibody discriminated best between pre-pandemic and COVID-19 sera and were selected for diagnostic evaluation. In the blind evaluation, two of these assays (Spike Pan ELISA and Spike-RBD Bridging LIPS assay) demonstrated >97% specificity and >92% sensitivity for samples from COVID-19 patients taken >21 days post symptom onset or PCR test. These assays offered better sensitivity for the detection of COVID-19 cases than a commercial assay which requires 100-fold larger serum volumes. This study demonstrates that low-volume in-house antibody assays can provide good diagnostic performance, and highlights the importance of using well-characterized samples and controls for all stages of assay development and evaluation. These cost-effective assays may be particularly useful for seroprevalence studies in low and middle-income countries.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.