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Park H, Yu C, Pirofski LA, Yoon H, Wu D, Li Y, Tarpey T, Petkova E, Antman EM, Troxel AB. Association between COVID-19 convalescent plasma antibody levels and COVID-19 outcomes stratified by clinical status at presentation. BMC Infect Dis 2024; 24:639. [PMID: 38926676 PMCID: PMC11201301 DOI: 10.1186/s12879-024-09529-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND There is a need to understand the relationship between COVID-19 Convalescent Plasma (CCP) anti-SARS-CoV-2 IgG levels and clinical outcomes to optimize CCP use. This study aims to evaluate the relationship between recipient baseline clinical status, clinical outcomes, and CCP antibody levels. METHODS The study analyzed data from the COMPILE study, a meta-analysis of pooled individual patient data from 8 randomized clinical trials (RCTs) assessing the efficacy of CCP vs. control, in adults hospitalized for COVID-19 who were not receiving mechanical ventilation at randomization. SARS-CoV-2 IgG levels, referred to as 'dose' of CCP treatment, were retrospectively measured in donor sera or the administered CCP, semi-quantitatively using the VITROS Anti-SARS-CoV-2 IgG chemiluminescent immunoassay (Ortho-Clinical Diagnostics) with a signal-to-cutoff ratio (S/Co). The association between CCP dose and outcomes was investigated, treating dose as either continuous or categorized (higher vs. lower vs. control), stratified by recipient oxygen supplementation status at presentation. RESULTS A total of 1714 participants were included in the study, 1138 control- and 576 CCP-treated patients for whom donor CCP anti-SARS-CoV2 antibody levels were available from the COMPILE study. For participants not receiving oxygen supplementation at baseline, higher-dose CCP (/control) was associated with a reduced risk of ventilation or death at day 14 (OR = 0.19, 95% CrI: [0.02, 1.70], posterior probability Pr(OR < 1) = 0.93) and day 28 mortality (OR = 0.27 [0.02, 2.53], Pr(OR < 1) = 0.87), compared to lower-dose CCP (/control) (ventilation or death at day 14 OR = 0.79 [0.07, 6.87], Pr(OR < 1) = 0.58; and day 28 mortality OR = 1.11 [0.10, 10.49], Pr(OR < 1) = 0.46), exhibiting a consistently positive CCP dose effect on clinical outcomes. For participants receiving oxygen at baseline, the dose-outcome relationship was less clear, although a potential benefit for day 28 mortality was observed with higher-dose CCP (/control) (OR = 0.66 [0.36, 1.13], Pr(OR < 1) = 0.93) compared to lower-dose CCP (/control) (OR = 1.14 [0.73, 1.78], Pr(OR < 1) = 0.28). CONCLUSION Higher-dose CCP is associated with its effectiveness in patients not initially receiving oxygen supplementation, however, further research is needed to understand the interplay between CCP anti-SARS-CoV-2 IgG levels and clinical outcome in COVID-19 patients initially receiving oxygen supplementation.
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Affiliation(s)
- Hyung Park
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA
| | - Chang Yu
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA
| | - Liise-Anne Pirofski
- Department of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Hyunah Yoon
- Department of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Danni Wu
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA
| | - Yi Li
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA
| | - Thaddeus Tarpey
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA
| | - Eva Petkova
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA
- Department of Child and Adolescent Psychiatry, NYU Grossman School of Medicine, New York, NY, USA
| | - Elliott M Antman
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Andrea B Troxel
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, USA.
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Jain A, Negi G, Kaur D, S V, Saxena V. Utility of COVID-19 Seropositive Plasma as Convalescent Plasma: An Immune and Neutralization Antibody Seroprevalence Analysis in Blood Donors for Future Potential Pandemic Readiness. Cureus 2024; 16:e57149. [PMID: 38681329 PMCID: PMC11055615 DOI: 10.7759/cureus.57149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2024] [Indexed: 05/01/2024] Open
Abstract
OBJECTIVES To analyze the seroprevalence of SARS-CoV-2 IgG antibodies and neutralizing antibodies in blood donors during the second wave of the pandemic and to explore the utility of COVID-19 seropositive plasma as convalescent plasma. MATERIALS AND METHODS In this study, 696 blood donors were tested for anti-SARS-CoV-2 IgG antibodies using a chemiluminescence assay. By blinding, 271 samples were chosen randomly for testing of neutralizing antibodies by enzyme-linked immunosorbent assay (ELISA) in duplicate among the 696 blood donors tested for anti-SARS-CoV-2 IgG antibodies, irrespective of the positivity or negativity of the result of the anti-SARS-CoV-2 IgG antibodies by chemiluminescence assay. IgG antibody levels were analyzed in signal-to-cutoff (S/Co), while neutralizing antibody levels were analyzed in percentage inhibition. RESULTS The seroprevalence of IgG antibodies based on the S/Co for the positive results ≥ 1.00 was 82.75%, while the seroprevalence of neutralizing antibodies based on the percentage inhibition for the positive results ≥ 30% was 89.59%. Frontline workers (FLWs) and Covishield-vaccinated individuals showed higher levels of the anti-SARS-CoV-2 IgG antibodies regarding higher S/Co. In comparison, levels of neutralization antibodies regarding percentage inhibition were higher only in FLWs. Covishield-vaccinated donors elicited a statistically higher seroprevalence of anti-SARS-CoV-2 IgG antibodies compared to the Covaxin-vaccinated, while the seroprevalence of neutralizing antibodies was not statistically different among this group. There was a positive correlation (0.762) between anti-SARS-CoV-2 IgG antibodies and neutralizing antibodies, and almost all donors' of S/Co ≥ 9.5 had neutralizing antibodies. CONCLUSION This study showed higher seroprevalence in the blood donor population compared to published seroprevalence in India's second wave of the pandemic. In the current study, 328 donors (47.12%) of the 696 screened donors were neither vaccinated nor had previous SARS-CoV-2 infection, but many had antibodies. The seroprevalence of neutralizing antibodies (96.42%) was higher than the seroprevalence of the anti-SARS-CoV-2 IgG antibodies (85.71%) in the donors who had previous infection of COVID-19. On the other hand, vaccinated donors showed similar immune responses for neutralizing antibodies and the anti-SARS-CoV-2 IgG antibodies. Higher IgG immune reactivity in S/Co showed a good correlation with neutralizing antibodies and can be used to screen whole blood donors for convalescent plasma donations.
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Affiliation(s)
- Ashish Jain
- Transfusion Medicine, All India Institute of Medical Sciences, Rishikesh, Rishikesh, IND
| | - Gita Negi
- Transfusion Medicine, All India Institute of Medical Sciences, Rishikesh, Rishikesh, IND
| | - Daljit Kaur
- Transfusion Medicine, All India Institute of Medical Sciences, Rishikesh, Rishikesh, IND
| | - Vivekanandhan S
- Biochemistry, All India Institute of Medical Sciences, Rishikesh, Rishikesh, IND
| | - Vartika Saxena
- Community and Family Medicine, All India Institute of Medical Sciences, Rishikesh, Rishikesh, IND
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3
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Farnsworth CW, O’Neil CA, Dalton C, McDonald D, Vogt L, Hock K, Arter O, Wallace MA, Muenks C, Amor M, Alvarado K, Peacock K, Jolani K, Fraser VJ, Burnham CAD, Babcock HM, Budge PJ, Kwon JH. Association between SARS-CoV-2 Symptoms, Ct Values, and Serological Response in Vaccinated and Unvaccinated Healthcare Personnel. J Appl Lab Med 2023; 8:871-886. [PMID: 37478837 PMCID: PMC10482509 DOI: 10.1093/jalm/jfad042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 05/15/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND SARS-CoV-2 vaccines are effective at reducing symptomatic and asymptomatic COVID-19. Limited studies have compared symptoms, threshold cycle (Ct) values from reverse transcription (RT)-PCR testing, and serological testing results between previously vaccinated vs unvaccinated populations with SARS-CoV-2 infection. METHODS Healthcare personnel (HCP) with a positive SARS-CoV-2 RT-PCR test within the previous 14 to 28 days completed surveys including questions about demographics, medical conditions, social factors, and symptoms of COVID-19. Ct values were observed, and serological testing was performed for anti-nucleocapsid (anti-N) and anti-Spike (anti-S) antibodies at enrollment and 40 to 90 days later. Serological results were compared to HCP with no known SARS-CoV-2 infection and negative anti-N testing. RESULTS There were 104 unvaccinated/not fully vaccinated and 77 vaccinated HCP with 2 doses of an mRNA vaccine at time of infection. No differences in type or duration of symptoms were reported (P = 0.45). The median (interquartile range [IQR]) Ct was 21.4 (17.6-24.6) and 21.5 (18.1-24.6) for the unvaccinated and vaccinated HCP, respectively. Higher anti-N IgG was observed in unvaccinated HCP (5.08 S/CO, 3.08-6.92) than vaccinated (3.61 signal to cutoff ratio [S/CO], 2.16-5.05). Anti-S IgG was highest among vaccinated HCP with infection (34 285 aribitrary units [AU]/mL, 17 672-61 775), followed by vaccinated HCP with no prior infection (1452 AU/mL, 791-2943), then unvaccinated HCP with infection (829 AU/mL, 290-1555). Anti-S IgG decreased 1.56% (0.9%-1.79%) per day in unvaccinated and 0.38% (0.03%-0.94%) in vaccinated HCP. CONCLUSIONS Vaccinated HCP infected with SARS-CoV-2 reported comparable symptoms and had similar Ct values relative to unvaccinated. However, vaccinated HCP had increased and prolonged anti-S and decreased anti-N response relative to unvaccinated.
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Affiliation(s)
- Christopher W Farnsworth
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Caroline A O’Neil
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Claire Dalton
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - David McDonald
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Lucy Vogt
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Karl Hock
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Olivia Arter
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Meghan A Wallace
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Carol Muenks
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Mostafa Amor
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Kelly Alvarado
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Kate Peacock
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Kevin Jolani
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Victoria J Fraser
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Carey-Ann D Burnham
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Hilary M Babcock
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Phillip J Budge
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
| | - Jennie H Kwon
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States
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Hindawi S, Elgemmezi T, A El-Kafrawy S, Samadani H, Tilmisani M, Assiri O, Raml M, I Azhar E, Badawi M. Assessment of the impact of pathogen reduction technologies on the neutralizing activity of COVID-19 convalescent plasma. Transfus Apher Sci 2023:103688. [PMID: 36922242 PMCID: PMC9984302 DOI: 10.1016/j.transci.2023.103688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/07/2023]
Abstract
COVID-19 convalescent plasma (CCP) could improve the clinical outcome of COVID-19 patients when high-titer CCP is administered in early stages of disease. However, CCP donors have a risk profile like first-time donors, pathogen reduction treatment (PRT) may mitigate such risk but should not impact CCP quality. The current study aims to assess the impact of PRT-technologies available in Saudi Arabia on the neutralizing activity of CCP. STUDY DESIGN: and Methods: CCP was collected from eligible donors by plasmapheresis. The neutralization titer was determined with an in-house microneutralization assay (MNA) using a local SARS-CoV-2 clinical isolate. Selected units were split and subject to PRT with amotosalen/UVA (AS) or Riboflavin/UVB (RB) (pairwise side-by-side comparison) followed by a second MNA analysis. 51 CCP units were collected, 27 were included in the analysis reaching the minimum MNA titer of 1:40 (4 reached high titer (≥1:250)). 27 CCP units were treated with AS and 14 with RB, the median MNA pre-treatment titer was 1:80 (1:40-640). The impact of AS and RB PRT on CCP neutralizing activity was not significantly different, nor in the total analysis neither in the pairwise comparison (94.6 vs 96.4 % retention, p > 0.05). No correlation of titer and blood group was observed, but a trend for increasing MNA titer with donor age, choosing donors with an age > 45 years would increase the number of high-titer CCP donors. The difference in impact of AS and RB on CCP MNA titer was below the limit of detection of the assay (0.5-fold).
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Affiliation(s)
- Salwa Hindawi
- Department of Hematology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Tarek Elgemmezi
- Blood Transfusion Services, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Sherif A El-Kafrawy
- Special Infectious Agents Unit BSL3, King Fahd Medical Research Center and Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hani Samadani
- Blood Transfusion Services, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Mayasim Tilmisani
- Blood Transfusion Services, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Omar Assiri
- Blood Transfusion Services, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Mohammad Raml
- Blood Transfusion Services, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Esam I Azhar
- Special Infectious Agents Unit BSL3, King Fahd Medical Research Center and Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Maha Badawi
- Department of Hematology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
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5
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Limited Correlation between SARS-CoV-2 Serologic Assays for Identification of High-Titer COVID-19 Convalescent Plasma Using FDA Thresholds. Microbiol Spectr 2022; 10:e0115422. [PMID: 35862939 PMCID: PMC9430146 DOI: 10.1128/spectrum.01154-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In August 2020, the Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for COVID-19 convalescent plasma (CCP) specified 12 authorized serologic assays and associated assay-specific cutoff values for the selection of high-titer CCP for use in hospitalized patients. The criteria used for establishing these cutoff values remains unclear. Here, we compare the overall agreement and concordance of five serologic assays included in the August 2020 FDA EUA at both the manufacturer-recommended qualitative cutoff thresholds and at the FDA-indicated thresholds for high-titer CCP, using serum samples collected as part of the CCP Expanded Access Program (EAP). The qualitative positive percent agreement (PPA) across assays ranged from 92.3% to 98.8%. However, the high-titer categorization across assays varied significantly, with the PPA ranging from 26.5% to 82.7%. The Roche anti-NC ECLIA provided the lowest agreement compared to all other assays. Efforts to optimize high-titer cutoffs could reduce, although not eliminate, the discordance across assays. The consequences of using nonstandardized assays are apparent in our study, and the high-titer cutoffs chosen for each assay are not directly comparable to each other. The generalized findings in our study will be relevant to any future use of convalescent plasma for either COVID-19 or future pandemics of newly emerged pathogens. IMPORTANCE COVID-19 convalescent plasma (CCP) was one of the first therapeutic options available for the treatment of SARS-CoV-2 infections and continues to be used selectively for immunosuppressed patients. Given the emergence of novel SARS-CoV-2 variants which are resistant to treatment with available monoclonal antibody (MAb) therapy, CCP remains an important therapeutic consideration. The FDA has released several emergency use authorizations (EUA) that have specified which serological assays can be used for qualification of CCP, as well as assay-specific cutoffs that must be used to identify high-titer CCP. In this study, a cohort of donor CCP was assessed across multiple serological assays which received FDA EUA for qualification of CCP. This study indicates a high degree of discordance across the assays used to qualify CCP for clinical use, which may have precluded the optimal use of CCP, including during clinical trials. This study highlights the need for assay standardization early in the development of serological assays for emerging pathogens.
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Belov A, Huang Y, Villa CH, Whitaker BI, Forshee R, Anderson SA, Eder A, Verdun N, Joyner MJ, Wright SR, Carter RE, Hung DT, Homer M, Hoffman C, Lauer M, Marks P. Early administration of COVID-19 convalescent plasma with high titer antibody content by live viral neutralization assay is associated with modest clinical efficacy. Am J Hematol 2022; 97:770-779. [PMID: 35303377 PMCID: PMC9082011 DOI: 10.1002/ajh.26531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 11/21/2022]
Abstract
The efficacy of COVID‐19 convalescent plasma (CCP) as a treatment for hospitalized patients with COVID‐19 remains somewhat controversial; however, many studies have not evaluated CCP documented to have high neutralizing antibody titer by a highly accurate assay. To evaluate the correlation of the administration of CCP with titer determined by a live viral neutralization assay with 7‐ and 28‐day death rates during hospitalization, a total of 23 118 patients receiving a single unit of CCP were stratified into two groups: those receiving high titer CCP (>250 50% inhibitory dilution, ID50; n = 13 636) or low titer CCP (≤250 ID50; n = 9482). Multivariable Cox regression was performed to assess risk factors. Non‐intubated patients who were transfused with high titer CCP showed 1.1% and 1.7% absolute reductions in overall 7‐ and 28‐day death rates, respectively, compared to those non‐intubated patients receiving low titer CCP. No benefit of CCP was observed in intubated patients. The relative benefit of high titer CCP was confirmed in multivariable Cox regression. Administration of CCP with high titer antibody content determined by live viral neutralization assay to non‐intubated patients is associated with modest clinical efficacy. Although shown to be only of modest clinical benefit, CCP may play a role in the future should viral variants develop that are not neutralized by other available therapeutics.
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Affiliation(s)
- Artur Belov
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Yin Huang
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Carlos H. Villa
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Barbee I. Whitaker
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Richard Forshee
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Steven A. Anderson
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Anne Eder
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Nicole Verdun
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
| | - Michael J. Joyner
- Department of Anesthesiology and Perioperative Medicine Mayo Clinic Rochester Minnesota USA
| | - Scott R. Wright
- Department of Cardiology and the Human Research Protection Program Mayo Clinic Rochester Minnesota USA
| | - Rickey E. Carter
- Department of Quantitative Health Sciences Mayo Clinic Jacksonville Florida USA
| | - Deborah T. Hung
- Infectious Disease and Microbiome Program Broad Institute Cambridge Massachusetts USA
| | - Mary Homer
- Biomedical Advanced Research and Development Authority (BARDA) District of Columbia Washington USA
| | - Corey Hoffman
- Biomedical Advanced Research and Development Authority (BARDA) District of Columbia Washington USA
| | - Michael Lauer
- Office of the Director National Institutes of Health Bethesda Maryland USA
| | - Peter Marks
- Center for Biologics Evaluation and Research US FDA Silver Spring Maryland USA
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7
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Qualitative and quantitative detection of SARS-CoV-2 antibodies from dried blood spots. Clin Biochem 2022; 117:16-22. [PMID: 34990593 PMCID: PMC8721924 DOI: 10.1016/j.clinbiochem.2021.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/20/2021] [Accepted: 12/30/2021] [Indexed: 01/13/2023]
Abstract
Introduction Dried blood spot (DBS) sampling is a minimally invasive method for specimen collection with potential multifaceted uses, particularly for serosurveillance of previous SARS-CoV-2 infection. In this study, we assessed DBS as a potential specimen type for assessing IgG and total (including IgG and IgM) antibodies to SARS-CoV-2 in vaccinated and naturally infected patients. Methods Six candidate buffers were assessed for eluting blood from DBS cards. The study utilized one hundred and five paired plasma specimens and DBS specimens from prospectively collected SARS-CoV-2 vaccinated individuals, remnants from those with PCR confirmed SARS-CoV-2 infections, or remnants from those without history of infection or vaccination. All specimens were tested with the Siemens SARS-CoV-2 total assay (COV2T) or IgG assay (sCOVG). Results The lowest backgrounds were observed with water and PBS, and water was used for elution. Relative to plasma samples, DBS samples had a positive percent agreement (PPA) of 94.4% (95% CI: 94.9–100%) for COV2T and 79.2 (68.4–87.0) for sCOVG using the manufacturer’s cutoff. The NPA was 100 % (87.1–100.0 and 85.13–100) for both assays. Dilution studies revealed 100% (95% CI: 90.8–100%) qualitative agreement between specimen types on the COV2T assay and 98.0% (88.0–99.9%) with the sCOVG using study defined cutoffs. Conclusion DBS specimens demonstrated high PPA and NPA relative to plasma for SARS-CoV-2 serological testing. Our data support feasibility of DBS sampling for SARS-CoV-2 serological testing.
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8
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Gallian P, Le Cam S, Brisbarre N, Pastorino B, Amroun A, Malard L, de Lamballerie X, Bliem C, Richard P, Morel P, Tiberghien P. COVID-19 convalescent plasma: Evolving strategies for serological screening in France. Vox Sang 2021; 117:606-610. [PMID: 34897745 DOI: 10.1111/vox.13228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 12/28/2022]
Abstract
Quantitation of anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) neutralizing antibodies (Nabs) is a key parameter in determining the effective dose for treatment with COVID-19 convalescent plasma (CCP). Interpretation of results from clinical trials conducted worldwide requires comparison of Nabs titres obtained from different methods. As virus neutralization tests (VNTs) are not standardized scalable or commercially available, strategies based on intensity of ELISA (Enzyme Linked Immunosorbent Assay) or chemiluminescent binding serological tests were implemented to allow comparisons and establish criteria for determining 'high-titres' of anti-SARS-CoV-2 antibodies (Abs). To this end, the FDA (Food and Drug Administration) has proposed criteria to define high-titre plasmas using different serological assays, including the one used in France for the CCP SARS-CoV-2 Abs screening (Euroimmun anti-S1 IgG). A retrospective study revealed that when using the FDA criteria (ELISA signal-to-cut-off [S/C ratio] ≥3.5), 91% of CCP had Nabs titres ≥40 as assessed with an in-house VNT. French strategy to ensure sufficient stocks of CCP of increasing titre has evolved over time. Recently, we improved our strategy by collecting only plasma from vaccinated convalescent donors as we confirmed that the mean IgG antibody level (ELISA S/C ratio) was significantly higher in plasma from vaccinated convalescent donors compared to donations from unvaccinated convalescent donors: 9.31 (CI 95%: 8.46-10.16) versus 3.22 (CI 95%: 3.05-3.39) (p < 0.001).
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Affiliation(s)
- Pierre Gallian
- Etablissement français du Sang, La Plaine Saint Denis, France.,Unité des Virus Émergents (UVE), Aix-Marseille Univ, IRD 190, Inserm 1207, IHU Méditerranée Infection, Marseille, France
| | - Sophie Le Cam
- Etablissement français du Sang, La Plaine Saint Denis, France
| | - Nadège Brisbarre
- Unité des Virus Émergents (UVE), Aix-Marseille Univ, IRD 190, Inserm 1207, IHU Méditerranée Infection, Marseille, France.,Etablissement français du Sang Provence Alpes Côte d'Azur et Corse, Marseille, France
| | - Boris Pastorino
- Unité des Virus Émergents (UVE), Aix-Marseille Univ, IRD 190, Inserm 1207, IHU Méditerranée Infection, Marseille, France
| | - Abdennour Amroun
- Unité des Virus Émergents (UVE), Aix-Marseille Univ, IRD 190, Inserm 1207, IHU Méditerranée Infection, Marseille, France
| | - Lucile Malard
- Etablissement français du Sang, La Plaine Saint Denis, France
| | - Xavier de Lamballerie
- Unité des Virus Émergents (UVE), Aix-Marseille Univ, IRD 190, Inserm 1207, IHU Méditerranée Infection, Marseille, France
| | - Cathy Bliem
- Etablissement français du Sang, La Plaine Saint Denis, France
| | - Pascale Richard
- Etablissement français du Sang, La Plaine Saint Denis, France
| | - Pascal Morel
- Etablissement français du Sang, La Plaine Saint Denis, France.,UMR RIGHT 1098, Inserm, EFS, Université de Franche Comté, Besançon, France
| | - Pierre Tiberghien
- Etablissement français du Sang, La Plaine Saint Denis, France.,UMR RIGHT 1098, Inserm, EFS, Université de Franche Comté, Besançon, France
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