Behnam Keshavarz1, Joesph R Wiencek2, Lisa J Workman1, Matthew D Straesser1, Lyndsey M Muehling1, Glenda Canderan1, Fabrizio Drago3, Catherine A Bonham4, Jeffrey M Sturek4, Chintan Ramani4, Coleen A McNamara3, Judith A Woodfolk1, Alexandra Kadl4,5, Thomas A E Platts-Mills1, Jeffrey M Wilson6. 1. Division of Allergy & Clinical Immunology, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA. 2. Department of Pathology, University of Virginia, Charlottesville, Virginia, USA. 3. Division of Cardiovascular Medicine and the Robert M. Berne Cardiovascular Center, University of Virginia, Charlottesville, Virginia, USA. 4. Division of Pulmonary and Critical Care, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA. 5. Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA. 6. Division of Allergy & Clinical Immunology, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA, jmw2gc@virginia.edu.
Abstract
BACKGROUND: Detailed understanding of the immune response to severe acute respiratory syndrome coronavirus (SARS-CoV)-2, the cause of coronavirus disease 2019 (CO-VID-19) has been hampered by a lack of quantitative antibody assays. OBJECTIVE: The objective was to develop a quantitative assay for IgG to SARS-CoV-2 proteins that could be implemented in clinical and research laboratories. METHODS: The biotin-streptavidin technique was used to conjugate SARS-CoV-2 spike receptor-binding domain (RBD) or nucleocapsid protein to the solid phase of the ImmunoCAP. Plasma and serum samples from patients hospitalized with COVID-19 (n = 60) and samples from donors banked before the emergence of COVID-19 (n = 109) were used in the assay. SARS-CoV-2 IgG levels were followed longitudinally in a subset of samples and were related to total IgG and IgG to reference antigens using an ImmunoCAP 250 platform. RESULTS: At a cutoff of 2.5 μg/mL, the assay demonstrated sensitivity and specificity exceeding 95% for IgG to both SARS-CoV-2 proteins. Among 36 patients evaluated in a post-hospital follow-up clinic, median levels of IgG to spike-RBD and nucleocapsid were 34.7 μg/mL (IQR 18-52) and 24.5 μg/mL (IQR 9-59), respectively. Among 17 patients with longitudinal samples, there was a wide variation in the magnitude of IgG responses, but generally the response to spike-RBD and to nucleocapsid occurred in parallel, with peak levels approaching 100 μg/mL, or 1% of total IgG. CONCLUSIONS: We have described a quantitative assay to measure IgG to SARS-CoV-2 that could be used in clinical and research laboratories and implemented at scale. The assay can easily be adapted to measure IgG to mutated COVID-19 proteins, has good performance characteristics, and has a readout in standardized units.
BACKGROUND: Detailed understanding of the immune response to severe acute respiratory syndrome coronavirus (SARS-CoV)-2, the cause of coronavirus disease 2019 (CO-VID-19) has been hampered by a lack of quantitative antibody assays. OBJECTIVE: The objective was to develop a quantitative assay for IgG to SARS-CoV-2 proteins that could be implemented in clinical and research laboratories. METHODS: The biotin-streptavidin technique was used to conjugate SARS-CoV-2 spike receptor-binding domain (RBD) or nucleocapsid protein to the solid phase of the ImmunoCAP. Plasma and serum samples from patients hospitalized with COVID-19 (n = 60) and samples from donors banked before the emergence of COVID-19 (n = 109) were used in the assay. SARS-CoV-2 IgG levels were followed longitudinally in a subset of samples and were related to total IgG and IgG to reference antigens using an ImmunoCAP 250 platform. RESULTS: At a cutoff of 2.5 μg/mL, the assay demonstrated sensitivity and specificity exceeding 95% for IgG to both SARS-CoV-2 proteins. Among 36 patients evaluated in a post-hospital follow-up clinic, median levels of IgG to spike-RBD and nucleocapsid were 34.7 μg/mL (IQR 18-52) and 24.5 μg/mL (IQR 9-59), respectively. Among 17 patients with longitudinal samples, there was a wide variation in the magnitude of IgG responses, but generally the response to spike-RBD and to nucleocapsid occurred in parallel, with peak levels approaching 100 μg/mL, or 1% of total IgG. CONCLUSIONS: We have described a quantitative assay to measure IgG to SARS-CoV-2 that could be used in clinical and research laboratories and implemented at scale. The assay can easily be adapted to measure IgG to mutated COVID-19 proteins, has good performance characteristics, and has a readout in standardized units.
Authors: Ingrid Sander; Sabine Kespohl; Eva Zahradnik; Philipp Göcke; Ingolf Hosbach; Burkhard L Herrmann; Thomas Brüning; Monika Raulf Journal: Clin Transl Immunology Date: 2022-01-30
Authors: Behnam Keshavarz; Nathan E Richards; Lisa J Workman; Jaimin Patel; Lyndsey M Muehling; Glenda Canderan; Deborah D Murphy; Savannah G Brovero; Samuel M Ailsworth; Will H Eschenbacher; Emily C McGowan; Barbara J Mann; Michael R Nelson; Alexandra Kadl; Judith A Woodfolk; Thomas A E Platts-Mills; Jeffrey M Wilson Journal: Front Immunol Date: 2022-03-21 Impact factor: 7.561
Authors: Jeffrey M Sturek; Tania A Thomas; James D Gorham; Chelsea A Sheppard; Allison H Raymond; Kristen Petros De Guex; William B Harrington; Andrew J Barros; Gregory R Madden; Yosra M Alkabab; David Y Lu; Qin Liu; Melinda D Poulter; Amy J Mathers; Archana Thakur; Dana L Schalk; Ewa M Kubicka; Lawrence G Lum; Scott K Heysell Journal: Microbiol Spectr Date: 2022-02-23
Authors: Tomasz Wasiluk; Magdalena Sredzinska; Anna Rogowska; Agnieszka Zebrowska; Barbara Boczkowska-Radziwon; Anna Stasiak-Barmuta; Piotr Radziwon Journal: Transfus Apher Sci Date: 2022-08-26 Impact factor: 2.596
Authors: Samuel M Ailsworth; Behnam Keshavarz; Nathan E Richards; Lisa J Workman; Deborah D Murphy; Michael R Nelson; Thomas A E Platts-Mills; Jeffrey M Wilson Journal: Ann Allergy Asthma Immunol Date: 2022-10-11 Impact factor: 6.248