Characteristics and serological patterns of COVID-19 convalescent plasma donors: optimal donors and timing of donation

Transfusion. 2020 Aug;60(8):1765-1772. doi: 10.1111/trf.15918. Epub 2020 Jul 6.

Abstract

Background: The lack of effective treatments against the 2019 coronavirus disease (COVID-19) has led to the exploratory use of convalescent plasma for treating COVID-19. Case reports and case series have shown encouraging results. This study investigated SARS-CoV-2 antibodies and epidemiological characteristics in convalescent plasma donors, to identify criteria for donor selection.

Methods: Recovered COVID-19 patients, aged 18-55 years, who had experienced no symptoms for more than 2 weeks, were recruited. Donor characteristics such as disease presentations were collected and SARS-CoV-2 N-specific IgM, IgG, and S-RBD-specific IgG levels were measured by enzyme-linked immunosorbent assay (ELISA).

Results: Whereas levels of N-specific IgM antibody declined after recovery, S-RBD-specific and N-specific IgG antibodies increased after 4 weeks from the onset of symptoms, with no significant correlation to age, sex, or ABO blood type. Donors with the disease presentation of fever exceeding 38.5°C or lasting longer than 3 days exhibited higher levels of S-RBD-specific IgG antibodies at the time of donation. Of the 49 convalescent plasma donors, 90% had an S-RBD-specific IgG titer of ≥1:160 and 78% had a titer of ≥1:640 at the time of plasma donation. Of the 30 convalescent plasma donors, who had donated plasma later than 28 days after the onset of symptoms and had a disease presentation of fever lasting longer than 3 days or a body temperature exceeding 38.5°C, 100% had an S-RBD-specific IgG titer of ≥1:160 and 93% had a titer of ≥1:640.

Conclusion: This study indicates that the S-RBD-specific IgG antibody reaches higher levels after 4 weeks from the onset of COVID-19 symptoms. We recommend the following selection criteria for optimal donation of COVID-19 convalescent plasma: 28 days after the onset of symptoms and with a disease presentation of fever lasting longer than 3 days or a body temperature exceeding 38.5°C. Selection based on these criteria can ensure a high likelihood of achieving sufficiently high S-RBD-specific IgG titers.

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Viral / blood*
  • Betacoronavirus / immunology*
  • Blood Donors*
  • COVID-19
  • Convalescence*
  • Coronavirus Infections / blood*
  • Coronavirus Infections / immunology
  • Coronavirus Infections / pathology
  • Coronavirus Infections / therapy
  • Fever
  • Humans
  • Immunization, Passive / standards
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Middle Aged
  • Pandemics
  • Pneumonia, Viral / blood*
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / pathology
  • SARS-CoV-2
  • Spike Glycoprotein, Coronavirus / immunology
  • Time Factors

Substances

  • Antibodies, Viral
  • Immunoglobulin G
  • Immunoglobulin M
  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2

Supplementary concepts

  • COVID-19 serotherapy