Article Text
Abstract
Background Complementopathy (rapid complement activation and consumption after trauma) has been reported in trauma patients, but the underlying mechanism of these phenomena and their clinical significance remain unclear. This study aimed to determine the complement/complement pathway activation and identify the association of complement activation with clinical outcomes in trauma patients.
Methods We studied 33 trauma patients with mean Injury Severity Score of 25, and 25 healthy volunteers. Sera were collected on patients’ arrival at the emergency department, as well as 1, 2, 3, 5, and 7 days after trauma, to measure the levels of terminal complement activation product soluble C5b-9 (sC5b-9) by ELISA. In addition, the functional complement activation pathway was evaluated using a commercial complement system screening kit.
Results Serum concentrations of sC5b-9 (complement terminal pathway activity) were significantly increased in trauma patients throughout the entire observation period except on day 1. Complement terminal activities were significantly higher in 27 of 33 patients with systemic inflammatory response syndrome (SIRS) than non-SIRS patients on day 2, day 5, and day 7. Increased serum levels of sC5b-9 positively correlated with SIRS. Functional complement analysis revealed that the classical pathway was the predominant pathway responsible for complement activation. Burn patients tended to have a greater and prolonged classical pathway activation than non-burn patients, and burn injury and blunt injury were associated with higher blood levels of sC5b-9 than penetrating injury.
Discussion Early complement activation through the classical pathway after trauma is observed and positively correlated with the development of SIRS. Thus, monitoring of the complement system might be beneficial in the care of critically injured patients.
Level of evidence III.
Study type Prognostic.
- complement system
- trauma
- prognosis
- systemic inflammatory response syndrome
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Footnotes
Presented at This study was presented as poster at the 2016 MHSRS (August 14–18, Kissimmee, Florida).
Contributors YL participated in the experimental design, performed measurement of sC5b-9 and functional complement pathway screening, data analysis and interpretation, and critical revision. QZ participated in literature search, data interpretation, and writing and formatting the article. BL conducted the assay of functional complement pathway screening. AD performed the data analysis. LC and MD provided critical revision. JDL participated in the experimental design, coordination, and article revision.
Funding This study was supported by a grant from US Army Medical Research and Materiel Command Combat Casualty Care Research Program (C_038_2014_USAISR).
Disclaimer The opinions or assertions expressed herein are the private views of the authors and are not to be construed as official or as reflecting the views of the US Department of the Army or the US Department of Defense.
Competing interests None declared.
Patient consent for publication Obtained.
Ethics approval The institutional review board of the US Army Medical Research and Materiel Command reviewed and approved the research protocol and granted a waiver of consent for the blood sampling as a minimal-risk intervention.
Provenance and peer review Not commissioned; externally peer reviewed.