| Autor: |
Lin YJ; Department of Medical Microbiology & Immunology, University of Albertagrid.17089.37, Edmonton, Alberta, Canada., Evans DH; Department of Medical Microbiology & Immunology, University of Albertagrid.17089.37, Edmonton, Alberta, Canada., Robbins NF; Scientific Affairs, Abbott Transfusion Medicine, Chicago, Illinois, USA., Orjuela G; Scientific Affairs, Abbott Transfusion Medicine, Bogotá, Colombia., Hu Q; Lunenfeld-Tanenbaum Research Institute at Mt. Sinai Hospital, Sinai Health, Toronto, Ontario, Canada., Samson R; Lunenfeld-Tanenbaum Research Institute at Mt. Sinai Hospital, Sinai Health, Toronto, Ontario, Canada.; Department of Molecular Genetics, University of Torontogrid.17063.33, Toronto, Ontario, Canada., Abe KT; Lunenfeld-Tanenbaum Research Institute at Mt. Sinai Hospital, Sinai Health, Toronto, Ontario, Canada.; Department of Molecular Genetics, University of Torontogrid.17063.33, Toronto, Ontario, Canada., Rathod B; Lunenfeld-Tanenbaum Research Institute at Mt. Sinai Hospital, Sinai Health, Toronto, Ontario, Canada., Colwill K; Lunenfeld-Tanenbaum Research Institute at Mt. Sinai Hospital, Sinai Health, Toronto, Ontario, Canada., Gingras AC; Lunenfeld-Tanenbaum Research Institute at Mt. Sinai Hospital, Sinai Health, Toronto, Ontario, Canada.; Department of Molecular Genetics, University of Torontogrid.17063.33, Toronto, Ontario, Canada., Tuite A; Dalla Lana School of Public Health, University of Torontogrid.17063.33, Toronto, Ontario, Canada., Yi QL; Epidemiology and Surveillance, Canadian Blood Servicesgrid.423370.1, Ottawa, Ontario, Canada.; School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada., O'Brien SF; Epidemiology and Surveillance, Canadian Blood Servicesgrid.423370.1, Ottawa, Ontario, Canada.; School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada., Drews SJ; Canadian Blood Servicesgrid.423370.1, Microbiology, Edmonton, Alberta, Canada.; Department of Laboratory Medicine and Pathology, University of Albertagrid.17089.37, Edmonton, Alberta, Canada. |
| Abstrakt: |
There is evidence that COVID-19 convalescent plasma may improve outcomes of patients with impaired immune systems; however, more clinical trials are required. Although we have previously used a 50% plaque reduction/neutralization titer (PRNT 50 ) assay to qualify convalescent plasma for clinical trials and virus-like particle (VLP) assays to validate PRNT 50 methodologies, these approaches are time-consuming and expensive. Here, we characterized the ability of the Abbott severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG II Quant assay to identify high- and low-titer plasma for wild-type and variant (Alpha, Beta, Gamma, and Delta) SARS-CoV-2 characterized by both VLP assays and PRNT 50 . Plasma specimens previously tested in wild-type, Alpha, Beta, Gamma, and Delta VLP neutralization assays were selected based on availability. Selected specimens were evaluated by the Abbott SARS-CoV-2 IgG II Quant assay [Abbott anti-Spike (S); Abbott, Chicago, IL], and values in units per milliliter were converted to binding antibody units (BAU) per milliliter. Sixty-three specimens were available for analysis. Abbott SARS-CoV-2 IgG II Quant assay values in BAU per milliliter were significantly different between high- and low-titer specimens for wild-type (Mann-Whitney U = 42, P < 0.0001), Alpha (Mann-Whitney U = 38, P < 0.0001), Beta (Mann-Whitney U = 29, P < 0.0001), Gamma (Mann-Whitney U = 0, P < 0.0001), and Delta (Mann-Whitney U = 42, P < 0.0001). A conservative approach using the highest 95% confidence interval (CI) values from wild-type and variant of concern (VOC) SARS-CoV-2 experiments would identify a potential Abbott SARS-CoV-2 IgG II Quant assay cutoff of ≥7.1 × 10 3 BAU/mL. IMPORTANCE The United States Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the use of COVID-19 convalescent plasma (CCP) to treat hospitalized patients with COVID-19 in August 2020. However, by 4 February 2021, the FDA had revised the convalescent plasma EUA. This revision limited the authorization for high-titer COVID-19 convalescent plasma and restricted patient groups to hospitalized patients with COVID-19 early in their disease course or hospitalized patients with impaired humoral immunity. Traditionally our group utilized 50% plaque reduction/neutralization titer (PRNT 50 ) assays to qualify CCP in Canada. Since that time, the Abbott SARS-CoV-2 IgG II Quant assay (Abbott, Chicago IL) was developed for the qualitative and quantitative determination of IgG against the SARS-CoV-2. Here, we characterized the ability of the Abbott SARS-CoV-2 IgG II Quant assay to identify high- and low-titer plasma for wild-type and variant (Alpha, Beta, Gamma, and Delta) SARS-CoV-2. |
