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Systems Analysis of the Neuroinflammatory and Hemodynamic Response to Traumatic Brain Injury
Published on: May 27, 2022
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Neutrophil-to-Lymphocyte Ratios and Infections after Traumatic Brain Injury: Associations with Hospital Resource
Marina Levochkina1,2, Leah McQuillan1, Nabil Awan1,3
1Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Journal of Clinical Medicine
|October 13, 2021
Summary
Traumatic brain injury (TBI) is linked to immune changes, specifically the neutrophil-to-lymphocyte ratio (NLR). Higher NLR trajectories post-TBI correlate with increased hospital-acquired infections, longer hospital stays, and worse outcomes.
Area of Science:
- Neuroscience
- Immunology
- Critical Care Medicine
Background:
- Traumatic brain injury (TBI) disrupts immune function, often indicated by an elevated neutrophil-to-lymphocyte ratio (NLR).
- The temporal patterns of NLR and their association with hospital-acquired infections (HAI), resource use, and patient outcomes after TBI are not well understood.
Purpose of the Study:
- To characterize the temporal dynamics of NLR in the first 21 days following moderate-to-severe TBI.
- To investigate the relationship between NLR trajectories, HAI development, hospital resource utilization, and patient outcomes.
Main Methods:
- Utilized group-based trajectory (TRAJ) and changepoint analyses to model NLR dynamics in 196 adult TBI patients.
- Employed mixed-effects multivariable regression to assess associations between NLR, HAI, length of stay (LOS), ventilation days, and Glasgow Outcome Scale (GOS) at six months.
Main Results:
- Identified two distinct NLR trajectories: high (n=67) and low (n=129).
- The high NLR trajectory group exhibited significantly higher rates and earlier onset of HAI (76.12% vs. 55.04%, p=0.004).
- Low lymphocyte counts early post-injury predicted later HAI and increased NLR. Both high NLR and HAI prolonged LOS and ventilation, but only high NLR predicted unfavorable six-month GOS (p=0.046).
Conclusions:
- Distinct NLR trajectories exist post-TBI, with high NLR associated with increased HAI risk and poorer outcomes.
- Immune dysregulation, evidenced by NLR changes and lymphocyte counts, significantly impacts infection susceptibility and clinical outcomes in TBI patients.
- Understanding these temporal immune dynamics is crucial for managing TBI patients, reducing HAI, optimizing resource use, and improving recovery.
