Evidence map›Paper›PMID 41721929›Full record

ArticleClinical and experimental medicine2026

Oxygen-dependent modulation of the human complement system during acute normobaric hypoxia: a translational plasma proteomics study.

Alexander Lang, Tin Yau Pang, Sarah Piel, Daniel Oehler, Elric Zweck, Khatereh Shahrjerdi, Madlen Okkasian, Jacqueline Georgy, Yvonne Reinders, Ashley-Jane Duplessis and 7 more

Abstract read
In one paragraph

Article in Clinical and experimental medicine, 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
–field-weighted citation impact
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

17 authors.

Alexander LangDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0001-6006-7109
Tin Yau PangDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0003-4738-4032
Sarah PielDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0002-1779-3532
Daniel OehlerDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0002-0435-4119
Elric ZweckDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0001-6739-476X
Khatereh ShahrjerdiDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0003-2985-9823
Madlen OkkasianDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0003-4075-2453
Jacqueline GeorgyDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0009-0000-5596-7524
Yvonne ReindersLeibniz-Institut für Analytische Wissenschaften-ISAS-e.V, Dortmund, Germany.ORCID http://orcid.org/0000-0003-1441-6149
Ashley-Jane DuplessisDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0002-9251-1371
Jens TankInstitute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.ORCID http://orcid.org/0000-0002-5672-1187
Jens JordanInstitute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.ORCID http://orcid.org/0000-0003-4518-0706
Susanne PfeilerDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0002-8591-6186
Albert SickmannLeibniz-Institut für Analytische Wissenschaften-ISAS-e.V, Dortmund, Germany.ORCID http://orcid.org/0000-0002-2388-5265
Malte KelmDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0003-0060-1052
Christian JungDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany.ORCID http://orcid.org/0000-0001-8325-250X
Norbert GerdesDivision of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty and University Hospital, Heinrich-Heine University, Moorenstr. 5, 40225, Düsseldorf, Germany. gerdes@hhu.de.ORCID http://orcid.org/0000-0002-4546-7208

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Acute hypoxia triggers multiple physiological and immune responses, yet the immediate systemic effects on circulating complement proteins remain insufficiently characterized. The complement cascade plays a central role in inflammation, host defense, and ischemia-related tissue injury, but its regulation during transient oxygen deprivation and reoxygenation in humans is poorly understood. Sixteen healthy volunteers were exposed to stepwise normobaric hypoxia simulating altitudes of 0, 2, 4, and 6 km (pO₂ = 9.64 kPa) followed by reoxygenation under normoxic conditions. Blood samples were collected at baseline, peak hypoxia (6 km), and after reoxygenation. Quantitative plasma proteomics was performed using targeted multiple-reaction-monitoring mass spectrometry to quantify key complement components (C1 complex, C3–C9, factor B) in 16 participants with complete datasets. Hematological parameters were analyzed in parallel. Hypoxia transiently increased leukocyte and platelet count, whereas hematocrit and mean corpuscular volume slightly decreased. While only slightly increasing during hypoxia, most complement peptides - including C1S, C1R, C3, C5, C7, C9, and CFAB - showed a coordinated reduction in relative abundance upon reoxygenation compared to both baseline and hypoxia (median fold-change ≈ 0.6–0.8; p < 0.05). Correlation analysis revealed coherent clustering among complement components but only weak associations with hematological indices. Acute hypoxia elicits rapid and reversible changes in the circulating complement peptide pool in healthy humans. Targeted plasma proteomics demonstrates clear oxygen-phase–dependent dynamics, with a coordinated decrease after reoxygenation. This pattern is consistent with reduced circulating availability of complement components, activation-associated consumption, and/or redistribution within the intravascular compartment. Future validation of these findings in certain patient cohorts may define translational relevance and functional consequences.

Indexed as

Complement System ProteinsHypoxiaOxygenPlasmaProteomeAdultFemaleHealthy VolunteersHumansMaleMass SpectrometryProteomicsYoung AdultComplement System ProteinsOxygenProteomeComplement systemHypoxiaInflammationInnate immunityPlasma proteomicsReoxygenation

Identifiers

PMID41721929
PMCPMC12932311

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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.