ArticleFrontiers in immunology2022
C5a elevation in convalescents from severe COVID-19 is not associated with early complement activation markers C3bBbP or C4d.
Article in Frontiers in immunology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.
What it found
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Who cites it
6 citing papers in PubMed, 6 citations in OpenAlex.
- C3d Complement Activation and Antibody Immunity in Convalescent COVID-19: Insights From Adults and Children.Journal of immunology research · 2026Article
- Impact of complement system proteins on the clinical progression of hospitalized patients with COVID-19.BMC infectious diseases · 2025Article
- Accurate Visualization of C4d Complement Fragment in Immunohistochemistry by C-Terminal Linear Neoepitope-Specific Antibodies.International journal of molecular sciences · 2024Article
- Type 2 Diabetes Mellitus Aggravates Complement Dysregulation and Affects Cortisol Response in Patients with Post-COVID-19.Diabetes, metabolic syndrome and obesity : targets and therapy · 2024Article
- Review
- Complement and COVID-19: Three years on, what we know, what we don't know, and what we ought to know.Immunobiology · 2023Review
Corrections and comments
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Authors and funding
9 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Numerous publications have underlined the link between complement C5a and the clinical course of COVID-19. We previously reported that levels of C5a remain high in the group of severely ill patients up to 90 days after hospital discharge. We have now evaluated which complement pathway fuels the elevated levels of C5a during hospitalization and follow-up. The alternative pathway (AP) activation marker C3bBbP and the soluble fraction of C4d, a footprint of the classical/lectin (CP/LP) pathway, were assessed by immunoenzymatic assay in a total of 188 serial samples from 49 patients infected with SARS-CoV-2. Unlike C5a, neither C3bBbP nor C4d readouts rose proportionally to the severity of the disease. Detailed correlation analyses in hospitalization and follow-up samples collected from patients of different disease severity showed significant positive correlations of AP and CP/LP markers with C5a in certain groups, except for the follow-up samples of the patients who suffered from highly severe COVID-19 and presented the highest C5a readouts. In conclusion, there is not a clear link between persistently high levels of C5a after hospital discharge and markers of upstream complement activation, suggesting the existence of a non-canonical source of C5a in patients with a severe course of COVID-19.
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