Prehospital immune responses and development of multiple organ dysfunction syndrome following traumatic injury: A prospective cohort study

PLoS Med. 2017 Jul 18;14(7):e1002338. doi: 10.1371/journal.pmed.1002338. eCollection 2017 Jul.

Abstract

Background: Almost all studies that have investigated the immune response to trauma have analysed blood samples acquired post-hospital admission. Thus, we know little of the immune status of patients in the immediate postinjury phase and how this might influence patient outcomes. The objective of this study was therefore to comprehensively assess the ultra-early, within 1-hour, immune response to trauma and perform an exploratory analysis of its relationship with the development of multiple organ dysfunction syndrome (MODS).

Methods and findings: The immune and inflammatory response to trauma was analysed in 89 adult trauma patients (mean age 41 years, range 18-90 years, 75 males) with a mean injury severity score (ISS) of 24 (range 9-66), from whom blood samples were acquired within 1 hour of injury (mean time to sample 42 minutes, range 17-60 minutes). Within minutes of trauma, a comprehensive leukocytosis, elevated serum pro- and anti-inflammatory cytokines, and evidence of innate cell activation that included neutrophil extracellular trap generation and elevated surface expression of toll-like receptor 2 and CD11b on monocytes and neutrophils, respectively, were observed. Features consistent with immune compromise were also detected, notably elevated numbers of immune suppressive CD16BRIGHT CD62LDIM neutrophils (82.07 x 106/l ± 18.94 control versus 1,092 x 106/l ± 165 trauma, p < 0.0005) and CD14+HLA-DRlow/- monocytes (34.96 x 106/l ± 4.48 control versus 95.72 x 106/l ± 8.0 trauma, p < 0.05) and reduced leukocyte cytokine secretion in response to lipopolysaccharide stimulation. Exploratory analysis via binary logistic regression found a potential association between absolute natural killer T (NKT) cell numbers and the subsequent development of MODS. Study limitations include the relatively small sample size and the absence of data relating to adaptive immune cell function.

Conclusions: Our study highlighted the dynamic and complex nature of the immune response to trauma, with immune alterations consistent with both activation and suppression evident within 1 hour of injury. The relationship of these changes, especially in NKT cell numbers, to patient outcomes such as MODS warrants further investigation.

MeSH terms

  • Adaptive Immunity*
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Cytokines / blood
  • England
  • Female
  • Humans
  • Immunity, Innate*
  • Injury Severity Score
  • Leukocytosis / blood
  • Leukocytosis / etiology
  • Leukocytosis / immunology
  • Male
  • Middle Aged
  • Multiple Organ Failure / blood
  • Multiple Organ Failure / etiology*
  • Multiple Organ Failure / immunology*
  • Prospective Studies
  • Time Factors
  • Wounds and Injuries / blood
  • Wounds and Injuries / complications*
  • Wounds and Injuries / immunology*
  • Young Adult

Substances

  • Cytokines

Grants and funding

For funding this research, the authors acknowledge the National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, which is joint funded by the Department of Health and Ministry of Defence (http://www.nihr.ac.uk; JH, DNN, ET, DD, JRBB, ZS, NC, AB, and JML), the Scar Free Foundation Birmingham Burns Research Centre, which is part of the Burns Collective within the Scar Free Foundation (www.scarfree.org.uk; PHam, RJD, and PHar), the RoseTrees Trust (www.rosetreestrust.co.uk; JH, AB, and JML; grant number, DTAA.RDBU18237), and the Medical Neuroscience Teaching and Research Fund (https://sites.google.com/site/mntrfund/; JH, AB, and JML; grant number, DTAA.RCLG19305). The authors would also like to acknowledge the Queen Elizabeth Hospital Birmingham Charity for funding the purchase of the Sysmex XN-1000 haematology analyser (https://www.qehb.org; PHar). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.