Evidence map›Paper›PMID 42212121›Full record

ArticleFrontiers in immunology2026

Complement activation in patients with post-acute sequelae after SARS-CoV-2 infection.

Madlene Holmqvist, Dick J Sjöström, Katherine Carlson, Birgitta Gullstrand, Anders A Bengtsson, Robin Kahn, Tom E Mollnes, Per Åkesson, Per H Nilsson, Fredrik Kahn

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Article in Frontiers in immunology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Madlene HolmqvistDivision of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
Dick J SjöströmDepartment of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden.
Katherine CarlsonDivision of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
Birgitta GullstrandDivision of Rheumatology, Department of Clinical Sciences, Lund University, Lund, Sweden.
Anders A BengtssonDivision of Rheumatology, Department of Clinical Sciences, Lund University, Lund, Sweden.
Robin KahnDivision of Pediatrics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
Tom E MollnesInstitute of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway.
Per ÅkessonDivision of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
Per H NilssonDepartment of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden.
Fredrik KahnDivision of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Post-acute sequelae of SARS-CoV-2 (PASC) may develop after SARS-CoV-2 infection and cause a wide range of symptoms that can persist for years. Several pathophysiological mechanisms have been proposed, including dysregulation of the complement system. Methods: In this study, we analysed markers of complement activation in a cohort of patients with PASC, up to 33 months after the initial infection. We measured the complement activation markers C3bc, C3bBbP and TCC in 38 PASC patients with an initial mild COVID-19 infection, 10 PASC patients with an initial severe COVID-19 infection and 80 control subjects who had recovered completely after a COVID-19 infection. Results: Although the patients with an acute mild SARS-CoV-2 infection had a trend towards more severe PASC, we could not find any significant differences in complement activation markers between these patients and controls. Conclusion: We could not find convincing evidence of activation of the complement system in PASC patients.

Indexed as

Complement ActivationCOVID-19SARS-CoV-2AdultAgedBiomarkersComplement C3bFemaleHumansMaleMiddle AgedPost-Acute COVID-19 SyndromeBiomarkersComplement C3bcomplement activationCOVID-19long COVIDPACSPASCpost COVID syndromeSARS-CoV-2

Identifiers

PMID42212121
PMCPMC13212466

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.