Autoantibodies in COVID-19 convalescent plasma donors

Jazbec Gradišar, Katerina (author), Žiberna, Klemen (author), Mali, Polonca (author), Marić, Ivica (author), Rožman, Primož (author), Maličev, Elvira (author)

Background and Objectives: Although COVID-19 convalescent plasma (CCP) has been successfully used to treat several viral infections, its effectiveness in neutralizing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its broader immunological safety remain debated. Since viral infections can trigger autoimmunity, particularly through molecular mimicry and immune dysregulation, there is growing interest in understanding whether CCP contains autoantibodies that could affect recipient safety. Materials and Methods: In this study, we evaluated the presence of 20 different autoantibodies, along with anti-SARS-CoV-2 antibodies, in plasma samples from CCP donors. Samples were collected at three time intervals following COVID-19 symptom onset: 0–60, 60–120 and 120–180 days. Results were compared with those from healthy control plasma donors. Results: Several autoantibodies— anti-Smith (anti-SM), anti-Sjögren syndrome antigen A, 60-kDa isoform (anti-SSA/Ro60), anti-proliferating cell nuclear antigen (anti-PCNA), anti-Ribosomal P and anti-ribonucleoprotein/Smith antigen complex (anti-RNP/SM)—showed modestly elevated levels in CCP samples collected within 0–60 days post symptom onset. In the 60–120-day period, autoantibody levels declined and approached levels observed in the control group. In the 120–180-day period, most autoantibody levels remained comparable to control levels. Our analysis showed no significant correlations between levels of neutralizing SARS-CoV-2 antibodies and autoantibody concentrations nor significant differences in autoantibody profiles between donors with high and low neutralizing antibody (NAb) titres. Conclusion: Our findings suggest that SARS-CoV-2 infection may transiently elevate certain autoantibodies in CCP donors. However, most autoantibody levels decline over time and the overall profiles do not indicate sustained autoreactivity. These results support the immunological safety of CCP, particularly when collected between 60 and 120 days post infection, and highlight the importance of timing in optimizing both efficacy and safety in plasma donation strategies.

• Language: English
• Keywords: COVID‐19 convalescent plasma, anti‐SARS‐CoV‐2 antibodies, autoantibodies, transfusion
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 54–63
• Numbering: Vol. 121, iss. 1
• PID: 20.500.12556/RUL-178019
• UDC: 616.1
• ISSN on article: 0042-9007
• DOI: 10.1111/vox.70140
• COBISS.SI-ID: 258034435
• Publication date in RUL: 16.01.2026

Record is a part of a journal

• Title: Vox sanguinis
• Shortened title: Vox sang.
• Publisher: Wiley, International Society of Blood Transfusion
• ISSN: 0042-9007
• COBISS.SI-ID: 210199

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: plazma okrevalca po COVID-19, protitelesa proti SARS-CoV-2, avtoprotitelesa, transfuzija