Early dynamic orchestration of immunologic mediators identifies multiply injured patients who are tolerant or sensitive to hemorrhage

Polytrauma impairs fracture healing accompanied by increased persistence of innate inflammatory stimuli and reduced adaptive response

The field of bone regeneration has primarily focused on investigating fracture healing and nonunion in isolated musculoskeletal injuries. Compared to isolated fractures, which frequently heal well, fractures in patients with multiple bodily injuries (polytrauma) may exhibit impaired healing. While some papers have reported the overall cytokine response to polytrauma conditions, significant gaps in our understanding remain in how fractures heal differently in polytrauma patients. We aimed to characterize fracture healing and the temporal local and systemic immune responses to polytrauma in a murine model of polytrauma composed of a femur fracture combined with isolated chest trauma. We collected serum, bone marrow from the uninjured limb, femur fracture tissue, and lung tissue over 3 weeks to study the local and systemic immune responses and cytokine expression after injury. Immune cell distribution was assessed by flow cytometry. Fracture healing was characterized using microcomputed tomography (microCT), histological staining, immunohistochemistry, mechanical testing, and small angle X-ray scattering. We detected more innate immune cells in the polytrauma group, both locally at the fracture site and systemically, compared to other groups. The percentage of B and T cells was dramatically reduced in the polytrauma group 6 h after injury and remained low throughout the study duration. Fracture healing in the polytrauma group was impaired, evidenced by the formation of a poorly mineralized and dysregulated fracture callus. Our data confirm the early, dysregulated inflammatory state in polytrauma that correlates with disorganized and impaired fracture healing.

Targeting Inflammation After Hemorrhagic Shock as a Molecular and Experimental Journey to Improve Outcomes: A Review

Hemorrhagic shock continues to be a major contributor to trauma-related fatalities globally, posing a significant and intricate pathophysiological challenge. The condition is marked by injury and blood loss, which activate molecular cascades that can quickly become harmful. The inflammatory response exhibits a biphasic pattern, beginning with a hyper-inflammatory phase that transitions into immunosuppression, posing significant obstacles to effective therapeutic interventions. This review article explores the intricate molecular mechanisms driving inflammation in hemorrhagic shock, emphasizing cellular signaling pathways, endothelial dysfunction, and immune activation. We discuss the role of molecular biomarkers in tracking disease progression and stratifying risk, with a focus on markers of endothelial dysfunction and inflammatory mediators as potential prognostic tools. Additionally, we assess therapeutic strategies, spanning traditional approaches like hemostatic resuscitation to advanced immunomodulatory treatments. Despite promising advancements in molecular monitoring and targeted therapies, challenges persist in bridging experimental findings with clinical applications. Future efforts must prioritize understanding the dynamic progression of inflammatory pathways and refining the timing of interventions to improve outcomes in hemorrhagic shock management.

Navigating Hemorrhagic Shock: Biomarkers, Therapies, and Challenges in Clinical Care

Hemorrhagic shock remains a leading cause of preventable death worldwide, with mortality patterns varying significantly based on injury mechanisms and severity. This comprehensive review examines the complex pathophysiology of hemorrhagic shock, focusing on the temporal evolution of inflammatory responses, biomarker utility, and evidence-based therapeutic interventions. The inflammatory cascade progresses through distinct phases, beginning with tissue injury and endothelial activation, followed by a systemic inflammatory response that can transition to devastating immunosuppression. Recent advances have revealed pattern-specific responses between penetrating and blunt trauma, necessitating tailored therapeutic approaches. While damage control resuscitation principles and balanced blood product administration have improved outcomes, many molecular targeted therapies remain investigational. Current evidence supports early hemorrhage control, appropriate blood product ratios, and time-sensitive interventions like tranexamic acid administration. However, challenges persist in biomarker validation, therapeutic timing, and implementation of personalized treatment strategies. Future directions include developing precision medicine approaches, real-time monitoring systems, and novel therapeutic modalities while addressing practical implementation barriers across different healthcare settings. Success in hemorrhagic shock management increasingly depends on integrating multiple interventions across different time points while maintaining focus on patient-centered outcomes.

Does Scheduled Low-Dose Short-Term NSAID (Ketorolac) Modulate Cytokine Levels After Orthopaedic Polytrauma? A Secondary Analysis of a Randomized Clinical Trial

OBJECTIVES

To determine whether scheduled low-dose, short-term ketorolac modulates cytokine concentrations in orthopaedic polytrauma patients.

METHODS

DESIGN

Secondary analysis of a double-blinded, randomized controlled trial.

SETTING

Single Level I trauma center from August 2018 to October 2022.

PATIENT SELECTION CRITERIA

Orthopaedic polytrauma patients between 18 and 75 years with a New Injury Severity Score greater than 9 were enrolled. Participants were randomized to receive 15 mg of intravenous ketorolac every 6 hours for up to 5 inpatient days or 2 mL of intravenous saline similarly.

OUTCOME MEASURES AND COMPARISONS

Daily concentrations of prostaglandin E2 and interleukin (IL)-1a, IL-1b, IL-6, and IL-10. Clinical outcomes included hospital and intensive care unit length of stay, pulmonary complications, and acute kidney injury.

RESULTS

Seventy orthopaedic polytrauma patients were enrolled, with 35 participants randomized to the ketorolac group and 35 to the placebo group. The overall IL-10 trend over time was significantly different in the ketorolac group ( P = 0.043). IL-6 was 65.8% higher at enrollment compared to day 3 ( P < 0.001) when aggregated over both groups. There was no significant treatment effect for prostaglandin E2, IL-1a, or IL-1b ( P > 0.05). There were no significant differences in clinical outcomes between groups ( P > 0.05).

CONCLUSIONS

Scheduled low-dose, short-term, intravenous ketorolac was associated with significantly different mean trends in IL-10 concentration in orthopaedic polytrauma patients with no significant differences in prostaglandin E2, IL-1a, IL-1b, or IL-6 levels between groups. The treatment did not have an impact on clinical outcomes of hospital or intensive care unit length of stay, pulmonary complications, or acute kidney injury.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Damage-control orthopedics or early total care: What you need to know

ABSTRACT

Patients with multisystem injuries are defined as multiply injured patients and may need multiple surgical procedures from more than one specialty. The importance of evaluating and understanding the resuscitation status of a multiple-injury patient is critical. Orthopedic strategies when caring for these patients include temporary stabilization or definitive early fixation of fractures while preventing further insult to other organ systems. This article will define multiple injuries and discuss specific markers used in assessing patients' hemodynamic and resuscitation status. The decision to use damage-control orthopedics or early total care for treatment of the patient are based on these factors, and an algorithm is presented to guide treatment. We will also discuss principles of external fixation and the management of pelvic trauma in a multiple-injury patient.

Complement system dysregulation in synovial fluid from patients with persistent inflammation following anterior cruciate ligament reconstruction surgery

INTRODUCTION

Patients with anterior cruciate ligament injury are at high risk of posttraumatic osteoarthritis and their response to reconstructive surgery and rehabilitation vary. Proteins identified in the orchestration of the acute inflammatory response may be predictive of patient outcomes.

OBJECTIVE

An unbiased, bottom-up proteomics approach was used to discover novel targets for therapeutics in relation to dysregulation in the orchestration of inflammatory pathways implicated in persistent joint inflammation subsequent to joint trauma.

METHODS

Synovial fluid was aspirated from patients at 1 week and 4 weeks after anterior cruciate ligament reconstruction (ACLR) and interleukin 6 (IL-6) concentrations were quantified by enzyme-linked immunosorbent assay. Patients were segregated into IL-6low and IL-6high groups based on IL-6 concentrations in synovial fluid at 4-weeks postoperation and proteins in synovial fluid were analyzed using qualitative, bottom-up proteomics. Abundance ratios were calculated for IL-6high and IL-6low groups as 4 weeks postoperation:1 week postoperation.

RESULTS

A total of 291 proteins were detected in synovial fluid, 34 of which were significantly (P < .05) differentially regulated between groups. Proteins associated with the classical and alternative complement cascade pathways were increased in the IL-6high compared to IL-6low group. Insulin-like growth factor-binding protein 6 (IGFBP-6) was increased by nearly 60-fold in the IL-6low group.

CONCLUSIONS

Patients segregated by IL-6 concentration in synovial fluid at 4 weeks post-ACLR demonstrated differential regulation of multiple pathways, providing opportunities to investigate novel targets, such as IGFBP-6, and to take advantage of therapeutics already approved for clinical use in other diseases that target inflammatory pathways, including the complement system.

Plasma interleukin responses as predictors of outcome stratification in patients after major trauma: a prospective observational two centre study

Background and objectives

There is a need to develop objective risk stratification tools to define efficient care pathways for trauma patients. Biomarker-based point of care testing may strengthen existing clinical tools currently available for this purpose. The dysregulation of pro- and anti-inflammatory cytokines in the pathogenesis of organ failure is well recognised. This study was carried out to evaluate whether blood concentrations of IL-6, IL-10, and IL-6:IL-10 ratios in the early stages of the illness are significantly different in patients with worsening organ function.

Materials and methods

In this prospective observational cohort study, plasma concentrations of IL-6 and IL-10 on days 1, 3 and 5 were measured in 91 major trauma patients using a multiplexed cytometric bead array approach. A composite measure of adverse outcome - defined as SOFA ≥ 2 or mortality at 7 days, was the primary outcome. IL-6 and IL-10 concentrations in early samples (days 1, 3 & 5) in patients who developed SOFA ≥ 2 on day 7 were compared against those who did not. Similar composite outcome groups at day 5 and in groups with worsening or improving SOFA scores (ΔSOFA) at days 7 and 5 were undertaken as secondary analyses.

Results

Stratification on day 7, 44 (48%) patients showed adverse outcomes. These adverse outcomes associated with significantly greater IL-6 concentrations on days 1 and 5 (Day 1: 47.65 [23.24-78.68] Vs 73.69 [39.93 - 118.07] pg/mL, P = 0.040 and Day 5: 12.85 [5.80-19.51] Vs 28.90 [8.78-74.08] pg/mL; P = 0.0019). Similarly, IL-10 levels were significantly greater in the adverse outcome group on days 3 and 5 (Day 3: 2.54 [1.76-3.19] Vs 3.16 [2.68-4.21] pg/mL; P = 0.044 and Day 5: 2.03 [1.65-2.55] Vs 2.90 [2.00-5.06] pg/mL; P <0.001). IL-6 and IL-10 concentrations were also significantly elevated in the adverse outcome groups at day 3 and day 5 when stratified on day 5 outcomes. Both IL-6 and IL-6:IL-10 were found to be significantly elevated on days 1 and 3 when stratified based on ΔSOFA at day 5. This significance was lost when stratified on day 7 scores.

Conclusions

Early IL-6 and IL-10 concentrations are significantly greater in patients who develop worsening organ functions downstream. These differences may provide an alternate biomarker-based approach to strengthen risk stratification in trauma patients.

Plasma proteomics reveals early, broad release of chemokine, cytokine, TNF, and interferon mediators following trauma with delayed increases in a subset of chemokines and cytokines in patients that remain critically ill

Severe injury is known to cause a systemic cytokine storm that is associated with adverse outcomes. However, a comprehensive assessment of the time-dependent changes in circulating levels of a broad spectrum of protein immune mediators and soluble immune mediator receptors in severely injured trauma patients remains uncharacterized. To address this knowledge gap, we defined the temporal and outcome-based patterns of 184 known immune mediators and soluble cytokine receptors in the circulation of severely injured patients. Proteomics (aptamer-based assay, SomaLogic, Inc) was performed on plasma samples drawn at 0, 24, and 72 hours (h) from time of admission from 150 trauma patients, a representative subset from the Prehospital Plasma during Air Medical Transport in Trauma Patients at Risk for Hemorrhagic Shock (PAMPer) trial. Patients were categorized into outcome groups including Early Non-Survivors (died within 72 h; ENS; n=38), Non-Resolvers (died after 72 h or required ≥7 days of intensive care; NR; n=78), and Resolvers (survivors that required < 7 days of intensive care; R; n=34), with low Injury Severity Score (ISS) patients from the Tranexamic Acid During Prehospital Transport in Patients at Risk for Hemorrhage After Injury (STAAMP) trial as controls. The major findings include an extensive release of immune mediators and cytokine receptors at time 0h that is more pronounced in ENS and NR patients. There was a selective subset of mediators elevated at 24 and 72 h to a greater degree in NR patients, including multiple cytokines and chemokines not previously described in trauma patients. These findings were validated in a quantitative fashion using mesoscale discovery immunoassays (MSD) from an external validation cohort (VC) of samples from 58 trauma patients matched for R and NR status. This comprehensive longitudinal description of immune mediator patterns associated with trauma outcomes provides a new level of characterization of the immune response that follows severe injury.

Patient-Specific Precision Injury Signatures to Optimize Orthopaedic Interventions in Multiply Injured Patients (PRECISE STUDY)

SUMMARY

Optimal timing and procedure selection that define staged treatment strategies can affect outcomes dramatically and remain an area of major debate in the treatment of multiply injured orthopaedic trauma patients. Decisions regarding timing and choice of orthopaedic procedure(s) are currently based on the physiologic condition of the patient, resource availability, and the expected magnitude of the intervention. Surgical decision-making algorithms rarely rely on precision-type data that account for demographics, magnitude of injury, and the physiologic/immunologic response to injury on a patient-specific basis. This study is a multicenter prospective investigation that will work toward developing a precision medicine approach to managing multiply injured patients by incorporating patient-specific indices that quantify (1) mechanical tissue damage volume; (2) cumulative hypoperfusion; (3) immunologic response; and (4) demographics. These indices will formulate a precision injury signature, unique to each patient, which will be explored for correspondence to outcomes and response to surgical interventions. The impact of the timing and magnitude of initial and staged surgical interventions on patient-specific physiologic and immunologic responses will be evaluated and described. The primary goal of the study will be the development of data-driven models that will inform clinical decision-making tools that can be used to predict outcomes and guide intervention decisions.

The Use of Multiplexing to Identify Cytokine and Chemokine Networks in the Immune-Inflammatory Response to Trauma

Significance: The immunoinflammatory responses that follow trauma contribute to clinical trajectory and patient outcomes. While remarkable advances have been made in trauma services and injury management, clarity on how the immune system in humans responds to trauma is lagging. Recent Advances: Multiplexing platforms have transformed our ability to analyze comprehensive immune mediator responses in human trauma. In parallel, with the establishment of large data sets, computational methods have been adapted to yield new insights based on mediator patterns. These efforts have added an important data layer to the emerging multiomic characterization of the human response to injury. Critical Issues: Outcome after trauma is greatly affected by the host immunoinflammatory response. Excessive or sustained responses can contribute to organ damage. Hence, understanding the pathophysiology behind traumatic injury is of vital importance. Future Directions: This review summarizes our work in the study of circulating immune mediators in trauma patients. Our foundational studies into dynamic patterns of inflammatory mediators represent an important contribution to the concepts and computational challenges that these large data sets present. We hope to see further integration and understanding of multiomics strategies in the field of trauma that can aid in patient endotyping and in potentially identifiying certain therapeutic targets in the future. Antioxid. Redox Signal. 35, 1393-1406.

Polytrauma: update on basic science and clinical evidence

The management of multiply injured or severely injured patients is a complex and dynamic process. Timely and safe fracture fixation is a critical component of the multidisciplinary care that these patients require. Effective management of these patients, and their orthopaedic injuries, requires a strong understanding of the pathophysiology of the response to trauma and indicators of patient status, as well as an appreciation for the dynamic nature of these parameters. Substantial progress in both clinical and basic science research in this area has advanced our understanding of these concepts and our approach to management of the polytraumatized patient. This article summarizes a symposium on this topic that was presented by an international panel of experts at the 2020 Virtual Annual Meeting of the Orthopaedic Trauma Association.