Selection of plasma donors for the production of anti-SARS-CoV-2 immunoglobulin-based therapies: Strategies for quantitative antibody measurements. (December 2022)

• Record Type: Journal Article
• Authors: Benites, Bruno Deltreggia; Costa-Lima, Carolina; Pinto, Fernanda Batista Rosa; da Costa, Vitor Antonio; Duarte, Adriana da Silva Santos; Zangirolami, Audrey Basso; Amaro, Emerson Clayton; Granja, Fabiana; Proenca-Modena, José Luiz; Saad, Sara Terezinha Olalla; Addas-Carvalho, Marcelo
• Is Part Of: Transfusion and apheresis science. Volume 61:Number 6(2022)
• Publication Date: 2022-12
• Subjects: Convalescent plasma -- Donation -- Immunoglobulins -- Neutralizing Antibodies -- SARS-Cov-2; Blood -- Transfusion -- Periodicals; Hemapheresis -- Periodicals; 615.39
• DOI: 10.1016/j.transci.2022.103513
• Languages: English
• ISSNs: 1473-0502

Abstract

Abstract: Even after two years of the pandemic, a completely effective treatment against SARS-CoV-2 has not yet been established. Considering this fact and the emergence of successive new viral variants, the development of therapies based on natural polyclonal antibodies recovered from convalescent plasma remains relevant. This study presents a comparison between different methods of screening antibodies in samples of 41 individuals previously diagnosed with COVID-19. We found a significant correlation between Abbot Architect anti-SARS-CoV-2 IgG and Abbott Allinity SARS-CoV-2 IgG II Quantitative assay intensity of reactivity and neutralizing antibody (nAb) titers. Thus, we propose an initial antibody screening with IgG anti-N Abbott Architect test, with an index of, for example, > 3.25 or SARS-CoV-2 IgG II Quantitative Abbott Allinity assay > 137.65 AU/mL as good predictors of Nab ≥ 1:80. For the quantitative method, this threshold demonstrated a 100 % sensitivity and 80 % specificity, with 97.3 % accuracy. An interesting observation was the increase in the neutralizing activity of the anti-SARS-CoV-2 antibodies with the longest interval between the end of the symptoms and the collection, demonstrating that the delay in plasma collection does not affect the achievement of adequate nAbs levels. These results demonstrate the possibility of using faster and more widely available commercial serological tests with a good correlation with viral neutralization tests in culture, allowing for optimized large-scale donor selection, which will be of utmost importance for the development of therapies such as hyperimmune immunoglobulin. Highlights: Commercial serological tests for anti-SARS-CoV-2 antibodies show good correlation with neutralizing antibodies in culture. This study demonstrates accurate cut-off points in serological tests for the selection of donors with nAbs > 1:80. We propose a strategy for the selection of donors that can be useful for the production of therapeutics on a large scale.