ABSTRACT
Background and Objectives COVID-19 convalescent plasma has become an experimental treatment option against SARS-CoV2. The aim of this study is to assess the impact of different pathogen reduction methods on the immunological properties of COVID-19 convalescent plasma.
Materials and Methods A total of 140 plasma doses collected by plasmapheresis from COVID-19 convalescent donors were subjected to pathogen reduction by three different methods: methylene blue (M), riboflavin (R), and amotosalen (A). To conduct a paired two-sample comparison, individual plasma doses were divided into 2 samples that were subjected to one of these methods. The titres of SARS-CoV2 neutralizing antibodies (NtAbs) and levels of specific immunoglobulins to RBD, S- and N-proteins of SARS-CoV-2 were measured before and after pathogen reduction.
Results All methods reduced NtAbs titres significantly but not equally: among units with the initial titre 80 or above, 81% of units had unchanged titres while 19% decreased by 1 step after methylene blue; 60% were unchanged and 40% decreased by 1 step after amotosalen; whereas after riboflavin 43% were unchanged, 50% had a one-step decrease and 7% a two-step decrease. Paired two-sample comparisons (M vs A, M vs R and A vs R) revealed that the most prominent and statistically significant decrease in all studied parameters (except anti-RBD) resulted from the riboflavin treatment.
Conclusion Pathogen reduction with methylene blue and amotosalen provides the greater likelihood of preserving the immunological properties of the COVID-19 convalescent plasma compared to riboflavin.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
This study was made possible in the context of Moscow Government COVID-19 Convalescent Plasma Program. Stanislav Volkovs research is partially supported by the Swedish Research Council and the Crafoord foundation.
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
Moscow Government Health Care Department
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
Yes
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Yes
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Yes
Footnotes
Conflict of interest: The authors declare no conflict of interests.
Funding: This study was made possible thanks to the support from the Moscow Government COVID-19 Convalescent Plasma Program. Stanislav Volkov’s research is partially supported by the Swedish Research Council and the Crafoord foundation.
Abstract and section "Results" as well as Figure 1 revised and uppdated because of incorrectly written values regarding the proportions of plasma units that had unchanged vs changed titers of virus neutralizing antibodies after different methods of pathogen reduction. One spelling error in the co-author name corrected.
Data Availability
All the data referred to at this manuscript is available