Characterization of 100 sequential SARS-CoV-2 convalescent plasma donations

Area of Science:

• Immunology
• Infectious Diseases
• Transfusion Medicine

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) convalescent plasma transfusion is a potential treatment for severe coronavirus disease 2019 (COVID-19).
• Treatment efficacy correlates with neutralizing antibody content in the plasma.
• Standardized measurement and donor selection are crucial for effective convalescent plasma collection.

Purpose of the Study:

• To correlate SARS-CoV-2 neutralizing antibody titers with binding antibody titers measured by ELISA.
• To assess the relationship between donor characteristics and antibody titers.
• To establish criteria for selecting potent convalescent plasma units for COVID-19 treatment.

Main Methods:

• Characterization of 100 convalescent plasma units for neutralizing and binding antibodies.
• Correlation analysis between neutralization assay and ELISA results.
• Analysis of donor demographics (COVID-19 severity, age, sex) and antibody titers.

Main Results:

• A significant but limited correlation (R² = 0.2830) was observed between neutralization and ELISA assays.
• Excluding high-titer units improved the correlation (R² = 0.5386).
• A trend suggested higher antibody titers in donors with increased disease severity, advanced age, and male sex, though functional relevance is uncertain.

Conclusions:

• ELISA can be used to propose a threshold for eliminating low-titer convalescent plasma units.
• Disease severity may be associated with higher neutralizing antibody titers, warranting further investigation.
• Optimized selection of convalescent plasma donors can enhance COVID-19 treatment efficacy.