Persistence of SARS-CoV-2 total immunoglobulins in a series of convalescent plasma and blood donors

  1. M. Carmen Martin
  2. Ana Jimenez
  3. Nuria Ortega
  4. Alba Parrado
  5. Isabel Page
  6. M. Isabel Gonzalez
  7. Lydia Blanco-Peris

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Abstract

The vast majority of COVID-19 cases both symptomatic and asymptomatic develop immunity after COVID-19 contagion. Whether lasting differences exist between infection and vaccination boosted immunity is yet to be known. The aim of this study was to determine how long total anti-SARS-CoV2 antibodies due to past infection persist in peripheral blood and whether sex, age or haematological features can influence their lasting.

Material and methods

A series of 2421 donations either of SARS-CoV-2 convalescent plasma or whole blood from 1107 repeat donors from January 2020 to March 2021 was analysed. An automated chemiluminescence immunoassay for total antibodies recognizing the nucleocapsid protein of SARS-CoV-2 in human serum and plasma was performed. Sex, age, blood group, blood cell counts and percentages and immunoglobulin concentrations were extracted from electronic recordings. Blood donation is allowed after a minimum of one-month post symptom’s relapse. Donors were 69.7% males and their average age was 46. The 250 donors who had later donations after a positive one underwent further analysis. Both qualitative (positivity) and quantitative (rise or decline of optical density regarding consecutive donations) outcomes were evaluated.

Results and discussion

In 97.6% of donors with follow-up, anti-SARS-CoV-2 protein N total antibodies remained positive at the end of a follow-up period of 12.4 weeks median time (1–46, SD = 9.65) after the first positive determination. The blood group was not related to antibody waning. Lower lymphocyte counts and higher neutrophils would help predict future waning or decay of antibodies. Most recovered donors maintain their total anti-SARS-CoV-2 N protein antibodies for at least 16 weeks (at least one month must have been awaited from infection resolution to blood donation). The 10 individuals that could be followed up longer than 40 weeks (approximately 44 weeks after symptom’s relapse) were all still positive.

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  1. Version published to 10.1371/journal.pone.0264124
  2. ScreenIT

    SciScore for 10.1101/2021.06.24.21259079: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: This study was conducted according with national regulations, institutional policies and in the tenets of the Helsinki Declaration, it was approved by the Valladolid Health Area Drug Research Ethics Committee, in a meeting held on June 11th, 2020 with the reference number “BIO-2020-93”.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    BlindingResearchers performing anti SARS-CoV-2 analyses were blind to the condition of COVID-19 convalescence and to any other characteristic of the donors or to the donation dates.
    Power Analysisnot detected.
    Cell Line AuthenticationAuthentication: A 100% concordance was yielded by all these validation assays.

    Table 2: Resources

    Antibodies
    SentencesResources
    The aim of this study was to determine how long anti SARS-CoV2 antibodies persisted in peripheral blood, and whether haematological o demographical parameters would be related to it.
    anti SARS-CoV2
    suggested: (Abcam Cat# ab273074, RRID:AB_2847846)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Although 71% of repeat donors in this study were convalescent plasma donors, one of our limitations is that we cannot recall how many of them developed severe symptoms. Some reports at the beginning of pandemics pointed out that up to 40% asymptomatic cases could lose their antibodies after 6 weeks from acute infection [13] but our data don’t support that statement. More recent studies [1] demonstrate that durable serum antibodies would be granted by long-lived plasma cells. Our study confirms that most individuals would keep their antibodies for 10 months or longer. Our results agree as well to others reporting a high percentage of individuals (above 75%) keeping antibodies positive for at least 9 months even when a titer decline is patent [14]. That would mean at least 50 weeks after contagion so far they’re not allowed to donate until 1 month after resolution of symptoms. Specific immunoglobulins would became detectable within 5-7 days post infection and seroconversion would happen after 10-14 days. Detectable levels of neutralizing antibodies against SARS-CoV-2 have been shown to start declining within three months of infection, especially among mild and asymptomatic cases [15]. Accordingly, one half (56.0%, Figure 1) of our donors exhibit a decay in their OD from total immunoglobulins anti SARS-COV-2 assay although most of them remain positive. Antibody waning would be independent of blood group in our cohort. Specific anti SARS-CoV-2 immunoglobulin loss would be a rare ...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  3. Version published to 10.1101/2021.06.24.21259079 on medRxiv