Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 2 de 2
Front Immunol ; 12: 739037, 2021.
Article in English | MEDLINE | ID: covidwho-1448729


Background: Transfusion of COVID-19 convalescent plasma (CCP) containing high titers of anti-SARS-CoV-2 antibodies serves as therapy for COVID-19 patients. Transfusions early during disease course was found to be beneficial. Lessons from the SARS-CoV-2 pandemic could inform early responses to future pandemics and may continue to be relevant in lower resource settings. We sought to identify factors correlating to high antibody titers in convalescent plasma donors and understand the magnitude and pharmacokinetic time course of both transfused antibody titers and the endogenous antibody titers in transfused recipients. Methods: Plasma samples were collected up to 174 days after convalescence from 93 CCP donors with mild disease, and from 16 COVID-19 patients before and after transfusion. Using ELISA, anti-SARS-CoV-2 Spike RBD, S1, and N-protein antibodies, as well as capacity of antibodies to block ACE2 from binding to RBD was measured in an in vitro assay. As an estimate for viral load, viral RNA and N-protein plasma levels were assessed in COVID-19 patients. Results: Anti-SARS-CoV-2 antibody levels and RBD-ACE2 blocking capacity were highest within the first 60 days after symptom resolution and markedly decreased after 120 days. Highest antibody titers were found in CCP donors that experienced fever. Effect of transfused CCP was detectable in COVID-19 patients who received high-titer CCP and had not seroconverted at the time of transfusion. Decrease in viral RNA was seen in two of these patients. Conclusion: Our results suggest that high titer CCP should be collected within 60 days after recovery from donors with past fever. The much lower titers conferred by transfused antibodies compared to endogenous production in the patient underscore the importance of providing CCP prior to endogenous seroconversion.

COVID-19/therapy , Convalescence , SARS-CoV-2/immunology , Seroconversion , Adult , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antigens, Viral/blood , Blood Donors , COVID-19/blood , COVID-19/immunology , Female , Humans , Immunization, Passive , Kinetics , Male , Middle Aged , Outpatients , RNA, Viral/blood
Arch Pathol Lab Med ; 145(10): 1221-1227, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1261421


CONTEXT.­: The ongoing COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has elicited a surge in demand for serologic testing to identify previously infected individuals. In particular, antibody testing is crucial in identifying COVID-19 convalescent plasma, which has been approved by the Food and Drug Administration under the Emergency Use Authorization for use as passive immunotherapy for hospitalized patients infected with COVID-19. Currently, high-titer COVID-19 convalescent plasma can be qualified by Ortho's Vitros COVID-19 IgG antibody test. OBJECTIVE.­: To explore the use of an efficient testing method to identify high-titer COVID-19 convalescent plasma for use in treating COVID-19-infected patients and track COVID-19 positivity over time. DESIGN.­: We evaluated an enzyme-linked immunosorbent assay (ELISA)-based method that detects antibodies specific to the SARS-CoV-2 receptor binding domain (RBD) with individual and pooled plasma samples and compared its performance against the Vitros COVID-19 IgG antibody test. Using the pooled RBD-ELISA (P-RE) method, we also screened more than 10 000 longitudinal healthy blood donor samples to assess seroprevalence. RESULTS.­: P-RE demonstrates 100% sensitivity in detecting Food and Drug Administration-defined high-titer samples when compared with the Vitros COVID-19 IgG antibody test. Overall sensitivity of P-RE when compared with the Vitros COVID-19 IgG antibody test and our individual sample RBD-ELISA (I-RE) were 83% and 56%, respectively. When screening 10 218 healthy blood donor samples by P-RE, we found the seroprevalence correlated with the local infection rates with a correlation coefficient of 0.21 (P < .001). CONCLUSIONS.­: Pooling plasma samples can be used to efficiently screen large populations for individuals with high-titer anti-RBD antibodies, important for COVID-19 convalescent plasma identification.

Antibodies, Viral/immunology , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Antibodies, Viral/blood , Blood Donors/statistics & numerical data , COVID-19/epidemiology , COVID-19/virology , Humans , Immunoglobulin G/blood , Pandemics/prevention & control , Reproducibility of Results , SARS-CoV-2/physiology , Sensitivity and Specificity , Seroepidemiologic Studies