The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications

Bacterial fluorescence imaging as a predictor of skin graft integration in burn wounds

BACKGROUND

Split-thickness skin graft (STSG)1 integration rates are susceptible to improvement. Infection and/or biofilm should be appropriately addressed prior to grafting to improve the likelihood of graft-take. Incorporating technological aids such as fluorescence (FL)2 imaging (MolecuLight®), which accurately locates areas of bacterial loads above 104 CFU/gr, for graft site assessment and preparation could yield better outcomes.

METHODS

This single-center, prospective observational study included adult burn patients with previously infected wounds that had been deemed clinically and microbiologically clean and were therefore candidates for grafting. Prior to grafting, a FL imaging assessment (blinded to the surgical team) localized areas positive for moderate-high bacterial loads (>104 CFU/gr). Intra-operatively, a standard swab sample from the recipient site was collected by the surgical team. Postoperatively, areas positive/negative for FL and areas of graft take and failure were overlapped and measured (cm2) over a 2D schematic. The performance and accuracy of FL imaging and swab sampling in relation to graft outcomes were assessed.

RESULTS

38 patients were enrolled in the study. The mean total body surface area (TBSA)3 involvement was 14.5 ± 12.4 % [range 0.8 - 40.2 %]. 25/38 of the subjects enrolled had complete graft take while 13 had partial graft losses. There were no total losses. FL-imaging was positive in 100 % of losses versus 31 % (4/13) of the swab microbiology. FL-imaging was found to have a sensitivity of 86 %, specificity of 98 %, PPV of 72 %, NPV of 99 %, and an accuracy of 94 % for predicting any type or range of graft loss in the entire cohort. Meanwhile, the sensitivity of microbiology from swab samples was 30 %, with a specificity of 76 %.

CONCLUSIONS

FL imaging is an accurate method for assessing recipient sites and predicting the outcome of a skin graft among burn patients. These findings suggest that FL imaging can inform better decision-making surrounding grafts that may lead to better outcomes.

LEVEL OF EVIDENCE

Level IIA, Therapeutic study.

Cytokine Profile of Adipose-Derived Stem Cells From Patients With Burn Injuries and Infection

INTRODUCTION

Adipose-derived stem cells (ASCs) are multipotent stem cells capable of differentiating into many cell lineages. They play an important role in wound healing by secreting cytokines. Prior studies have demonstrated the presence of proinflammatory cytokines in burn wounds. However, no studies have been performed evaluating the cytokines released by burn wounds with infections. We hypothesized that there is an alteration in the paracrine factors secreted by ASCs in burn wounds with concomitant infections.

METHODS

Adipose tissue was collected from patients with burn injuries at their index operation. ASCs were extracted and grown under standard tissue culture techniques. The supernatant was extracted. Cytokine analyses were performed with multiplex assays. Infection was determined using a burn sepsis protocol. The cytokine profiles of the two groups were compared using a Mann-Whitney U test.

RESULTS

Sixteen patients were enrolled in the study, 50% with bacterial infection (n = 8). There was no significant difference in the baseline demographics of the two groups (P > 0.05). There were significantly lower concentrations of interleukin 13 and interferon gamma (P < 0.05) in burn patients with concomitant infections.

CONCLUSIONS

ASCs are critical to burn wound healing. This study demonstrated diminished production of interleukin 13, an immunoregulatory cytokine involved in the antiinflammatory pathway by downregulating macrophage activity. This study also demonstrated significantly lower levels of interferon gamma in patient with burns and concomitant infection. This cytokine is crucial for antimicrobial defenses.

Overview of secondary immunodeficiency

In contrast to inborn errors of immunity (IEI), which are inherited disorders of the immune system that predispose to infections, malignancy, atopy, and immune dysregulation, secondary immunodeficiencies and immune dysregulation states (SID) are acquired impairments in immune cell function and/or regulation, and may be transient, reversible, or permanent. SIDs can derive from a variety of medical comorbidities, including protein-losing conditions, malnutrition, malignancy, certain genetic syndromes, prematurity, and chronic infections. Medications, including immunosuppressive and chemotherapeutic drugs, can have profound effects on immunity and biologic agents used in rheumatology, neurology, and hematology/oncology practice are increasingly common causes of SID. Iatrogenic factors, including surgical procedures (thymectomy, splenectomy) can also contribute to SID. A thorough case history, medication review, and laboratory evaluation are necessary to identify the primary driver and determine proper management of SID. Careful consideration should be given to whether a primary IEI could be contributing to autoimmunity, malignancy, and posttreatment complications (e.g., antibody deficiency). SID management consists of addressing the driving condition and/or removing the offending agent if feasible. If SID is suspected to be permanent, then antibiotic prophylaxis, additional immunization, and immunoglobulin replacement should be considered.

Pediatric Burns: From Acute Care Through Reconstruction in 2024

Children are disproportionately affected by burn injuries. Differences between adult and pediatric burns range from epidemiologic characteristics to pathophysiological considerations, which vary between different age subgroups. All these factors must be considered in each phase of burn care. This article reviews the most important aspects of the management of a pediatric burned patient starting from the acute through reconstructive phases.

Identification of early coagulation changes associated with survival outcomes post severe burns from multiple perspectives

Coagulation alterations manifest early after severe burns and are closely linked to mortality outcomes. Nevertheless, the precise characterization of coagulation changes associated with early mortality remains elusive. We examined alterations in indicators linked to mortality outcomes at both the transcriptomic and clinical characteristic levels. At the transcriptomic level, we pinpointed 28 differentially expressed coagulation-related genes (DECRGs) following burn injuries and endeavored to validate their causal relationships through Mendelian randomization. DECRGs tied to survival exhibit a significant association with neutrophil function, wherein the expression of CYP4F2 and P2RX1 serves as robust predictors of fatal outcomes. In terms of clinical indicators, early levels of D-dimer and alterations in serum calcium show a strong correlation with mortality outcomes. Coagulation depletion and fibrinolytic activation, stemming from the hyperactivation of coagulation pathways post-severe burns, are strongly linked to patient mortality. Monitoring these early coagulation markers with predictive value can effectively identify individuals necessitating priority critical care.

Filter Lifespan, Treatment Effect, and Influencing Factors of Continuous Renal Replacement Therapy for Severe Burn Patients

Continuous renal replacement therapy (CRRT) is often disrupted due to various factors, such as patient-related issues, vascular access complications, treatment plans, and medical staff factors. This unexpected interruption is referred to as non-selective filter stoppage and can result in additional treatment expenses. This study conducted a retrospectively analyzed 501 CRRT filters used in 62 patients with severe burns, lifespan and therapeutic effect of all filters were mainly analyzed, used logistic regression analysis was performed to identify risk factors associated with non-selective cessation filters. Out of 493 filters, 279 cases received heparin (56.60%), the median lifespan of the filter was 14.08 h (25th, 75th quantile: 7.30, 21.50); 128 cases were treated with nafamostat mesylate (26.00%), and the median lifespan of the filter was 16.42 h (10.49, 22.76); 86 cases were treated with sodium citrate (17.40%), and the median lifespan of the filter was 31.06 h (19.25, 48.75). In addition, significant differences were observed in the electrolyte index, renal function index, and procalcitonin levels before and after treatment with a single filter (P < .001). Multivariate logistic regression showed that the risk of non-selective cessation of sodium citrate anticoagulants was lower than that of heparin anticoagulation. Overall, CRRT is progressively becoming more prevalent in the treatment of patients with severe burns. The lifespan of individual filters and total patient treatment duration showed a consistent upward trend. The filter's lifespan was notably greater during sodium citrate anticoagulation when compared to nafamostat mesylate and heparin, meanwhile notably reducing the risk of non-selective cessation. Therefore, we recommend sodium citrate for anticoagulation in patients without any contraindications.

Evaluating the efficacy of standardized pressure ulcer management protocols in the prevention of pressure injuries among patients undergoing neurosurgical procedures

Pressure injuries are a significant concern for patients undergoing neurosurgical procedures due to prolonged immobility and the complexity of care. This study evaluates the efficacy of standardized pressure ulcer management protocols in preventing pressure injuries and enhancing patient care in a neurosurgical context. A comprehensive retrospective analysis was conducted at a single institution from December 2020 to December 2023, comparing 50 patients who received standardized pressure ulcer management (intervention group) with 50 patients who received conventional care (control group). The study assessed the incidence of pressure ulcers, patient comfort levels using the Kolcaba Comfort Scale and sleep quality using the Richards-Campbell Sleep Questionnaire (RCSQ). Statistical analysis was performed using SPSS software, version 27.0, applying t-tests and chi-square tests as appropriate. The intervention group exhibited a significantly lower incidence of pressure ulcers at all measured time points post-surgery compared to the control group. Patient comfort levels in the intervention group were consistently higher across psychological, environmental, physiological and socio-cultural domains. Sleep quality metrics, including sleep depth, latency to sleep onset and overall sleep quality, were significantly improved in the intervention group. The implementation of standardized pressure ulcer management protocols in neurosurgical care significantly reduces the incidence of pressure injuries, enhances patient comfort and improves sleep quality. These findings highlight the importance of adopting structured care protocols to improve postoperative outcomes and patient well-being in neurosurgical settings.

Advancements in Regenerative Hydrogels in Skin Wound Treatment: A Comprehensive Review

This state-of-the-art review explores the emerging field of regenerative hydrogels and their profound impact on the treatment of skin wounds. Regenerative hydrogels, composed mainly of water-absorbing polymers, have garnered attention in wound healing, particularly for skin wounds. Their unique properties make them well suited for tissue regeneration. Notable benefits include excellent water retention, creating a crucially moist wound environment for optimal healing, and facilitating cell migration, and proliferation. Biocompatibility is a key feature, minimizing adverse reactions and promoting the natural healing process. Acting as a supportive scaffold for cell growth, hydrogels mimic the extracellular matrix, aiding the attachment and proliferation of cells like fibroblasts and keratinocytes. Engineered for controlled drug release, hydrogels enhance wound healing by promoting angiogenesis, reducing inflammation, and preventing infection. The demonstrated acceleration of the wound healing process, particularly beneficial for chronic or impaired healing wounds, adds to their appeal. Easy application and conformity to various wound shapes make hydrogels practical, including in irregular or challenging areas. Scar minimization through tissue regeneration is crucial, especially in cosmetic and functional regions. Hydrogels contribute to pain management by creating a protective barrier, reducing friction, and fostering a soothing environment. Some hydrogels, with inherent antimicrobial properties, aid in infection prevention, which is a crucial aspect of successful wound healing. Their flexibility and ability to conform to wound contours ensure optimal tissue contact, enhancing overall treatment effectiveness. In summary, regenerative hydrogels present a promising approach for improving skin wound healing outcomes across diverse clinical scenarios. This review provides a comprehensive analysis of the benefits, mechanisms, and challenges associated with the use of regenerative hydrogels in the treatment of skin wounds. In this review, the authors likely delve into the application of rational design principles to enhance the efficacy and performance of hydrogels in promoting wound healing. Through an exploration of various methodologies and approaches, this paper is poised to highlight how these principles have been instrumental in refining the design of hydrogels, potentially revolutionizing their therapeutic potential in addressing skin wounds. By synthesizing current knowledge and highlighting potential avenues for future research, this review aims to contribute to the advancement of regenerative medicine and ultimately improve clinical outcomes for patients with skin wounds.

Unremitting pro-inflammatory T-cell phenotypes, and macrophage activity, following paediatric burn injury

Objectives

The aim of this study was to characterise the dynamic immune profile of paediatric burn patients for up to 18 months post-burn.

Methods

Flow cytometry was used to measure 25 cell markers, chemokines and cytokines which reflected both pro-inflammatory and anti-inflammatory immune profiles. Peripheral blood mononuclear cells from 6 paediatric burn patients who had returned for repeated burn and scar treatments for > 4 timepoints within 12 months post-burn were compared to four age-matched healthy controls.

Results

While overall proportions of T cells, NK cells and macrophages remained relatively constant, over time percentages of these immune cells differentiated into effector and proinflammatory cell phenotypes including Th17 and activated γδ T cells. Circulating proportions of γδ T cells increased their expression of pro-inflammatory mediators throughout the burn recovery, with a 3-6 fold increase of IL-17 at 1-3 weeks, and NFκβ 9-18 months post-burn. T-regulatory cell plasticity was also observed, and Treg phenotype proportions changed from systemically reduced skin-homing T-regs (CCR4+) and increased inflammatory (CCR6+) at 1-month post-burn, to double-positive cell types (CCR4+CCR6+) elevated in circulation for 18 months post-burn. Furthermore, Tregs were observed to proportionally express less IL-10 but increased TNF-α over 18 months.

Conclusion

Overall, these results indicate the circulating percentages of immune cells do not increase or decrease over time post-burn, instead they become highly specialised, inflammatory and skin-homing. In this patient population, these changes persisted for at least 18 months post-burn, this 'immune distraction' may limit the ability of immune cells to prioritise other threats post-burn, such as respiratory infections.

Coenzyme Q10 supplementation in burn patients: a double-blind placebo-controlled randomized clinical trial

BACKGROUND

Burn injuries are important medical problems that, aside from skin damage, cause a systemic response including inflammation, oxidative stress, endocrine disorders, immune response, and hypermetabolic and catabolic responses which affect all the organs in the body. The aim of this study was to determine the effect of coenzyme Q10 (CoQ10) supplementation on inflammation, oxidative stress, and clinical outcomes in burn patients.

METHODS

In a double-blind placebo-controlled randomized clinical trial, 60 burn patients were randomly assigned to receive 100 mg CoQ10 three times a day (total 300 mg/day) or a placebo for 10 days. Inflammatory markers including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), oxidative stress markers including total antioxidant capacity (TAC), malondialdehyde (MDA) and superoxide dismutase (SOD) activity, fasting blood glucose (FBG), blood urea nitrogen (BUN), creatinine, white blood cells (WBC), and body temperature were assessed as primary outcomes and albumin, prothrombin time (PT), partial thromboplastin time (PTT), international normalized ratio (INR), other hematological parameters, blood pressure, O2 saturation, ICU duration, and 28-mortality rate were assessed as secondary outcomes.

RESULTS

Fifty-two participants completed the trial. CRP and ESR levels were not significantly different between CoQ10 and placebo groups at the end of the study (P = 0.550 and P = 0.306, respectively). No significant differences between groups were observed for TAC (P = 0.865), MDA (P = 0.692), and SOD activity (P = 0.633) as well. Administration of CoQ10 resulted in a significant increase in albumin levels compared to placebo (P = 0.031). There was no statistically significant difference between the two groups in other measured outcomes (P > 0.05).

CONCLUSION

Results showed that in patients with burn injury, CoQ10 administration had no effect on inflammatory markers and oxidative stress, although serum albumin levels were improved after supplementation. Further studies with albumin as the primary outcome are needed to confirm this finding.

Therapeutic effect of mitochondrial transplantation on burn injury

As mitochondrial damage or dysfunction is commonly observed following burn injuries, we investigated whether mitochondrial transplantation (MT) can result in therapeutic benefits in the treatment of burns. Human immortalized epidermal cells (HaCaT) and Kunming mice were used to establish a heat-injured cell model and a deep partial-thickness skin burn animal model, respectively. The cell model was established by exposing HaCaT cells to 45 or 50 °C for 10 min, after which cell proliferation was assayed using fluorescent double-staining and colony formation assays, cell migration was assessed using colloidal gold migration and scratch assays, and cell cycle progression and apoptosis were measured by flow cytometry. Histopathological staining, immunohistochemistry, nick-end labeling analysis, and enzyme-linked immunosorbent assays were used to evaluate the effects of MT on inflammation, tissue recovery, apoptosis, and scar growth in a mouse model. The therapeutic effects were observed in the heat-injured HaCaT cell model. MT promoted cell viability, colony formation, proliferation, and migration; decreased G1 phase; promoted cell division; and decreased apoptosis. Wound-healing promotion, anti-inflammation (decreased mast cell aggregation, down-regulated of TNF-α, IL-1β, IL-6, and up-regulated IL-10), acceleration of proliferation recovery (up-regulated CD34 and VEGF), apoptosis reduction, and scar formation reduction (decreased collagen I/III ratio and TGF-β1) were observed in the MT mouse model. The MT mode of action was, however, not investigated in this study. In conclusion, our data indicate that MT exerts a therapeutic effect on burn injuries both in vitro and in vivo.

Beyond the burn: An observational study of cardiovascular risk in burn survivors in the north of Iran

Burn survivors experience profound physiological changes following injury, which may have lasting implications for cardiovascular health. This study aims to investigate the cardiovascular risk profile among burn survivors treated at a burn center in northern Iran. This observational study was conducted from 2022 to 2023 at the burn centre affiliated with Guilan University of Medical Sciences, Rasht, Iran. This study assessed a cohort study of 210 burn survivors, focusing on individuals with ≥20% TBSA burn injuries who had recovered and returned to their daily lives. This study assessed patients' lipid profiles, Framingham General Cardiovascular Risk Score (FGCRS) and risk factors, including demographics, clinical variables and physical activity. Statistical analysis employed descriptive and inferential statistics. The mean age was 49.23 years, and the mean TBSA burned was 37.06%. The risk of cardiovascular disease in 66% of the study population was less than 10%, and in 13%, it was more than 20%. Significant associations were identified between CVD risk and sex, diabetes, hypertension, BMI, TBSA burned, years after burn, physical activity level and LDL. Of the lipid profile measures, LDL, triglycerides and TC/HDL exceeded the desirable levels. This research highlights the heightened cardiovascular risk in burn survivors, emphasizing the necessity for targeted interventions and regular monitoring. Identifying modifiable risk factors enables healthcare practitioners to develop tailored strategies, enhancing cardiovascular health in this vulnerable population and improving overall outcomes and quality of life.

Therapeutic implications of extracorporeal shock waves in burn wound healing

Burns are a common type of trauma that seriously affect not only the physical health, but also the mental health and quality of life of the patient. Extracorporeal shock wave therapy (ESWT) is an emerging treatment that has been used in clinical treatment. It has many advantages, including safety, non-invasiveness, efficiency, short treatment duration, fewer complications, and relatively low prices. In clinical settings, ESWT has played an important role in the healing process of burns and the prevention of sequelae. This article reviews the history of ESWT, the mechanism of ESWT to promote burn healing, and the application of ESWT in burns. Current status of ESWT treatment for burns as well as future perspectives for research have been summarized and proposed. However, patients with burns cannot be considered recovered when the wounds have healed, we need some new technology to adjust to the challenges of the future.

An in silico modeling approach to understanding the dynamics of the post-burn immune response

Introduction

Burns are characterized by a massive and prolonged acute inflammation, which persists for up to months after the initial trauma. Due to the complexity of the inflammatory process, Predicting the dynamics of wound healing process can be challenging for burn injuries. The aim of this study was to develop simulation models for the post-burn immune response based on (pre)clinical data.

Methods

The simulation domain was separated into blood and tissue compartments. Each of these compartments contained solutes and cell agents. Solutes comprise pro-inflammatory cytokines, anti-inflammatory cytokines and inflammation triggering factors. The solutes diffuse around the domain based on their concentration profiles. The cells include mast cells, neutrophils, and macrophages, and were modeled as independent agents. The cells are motile and exhibit chemotaxis based on concentrations gradients of the solutes. In addition, the cells secrete various solutes that in turn alter the dynamics and responses of the burn wound system.

Results

We developed an Glazier-Graner-Hogeweg method-based model (GGH) to capture the complexities associated with the dynamics of inflammation after burn injuries, including changes in cell counts and cytokine levels. Through simulations from day 0 - 4 post-burn, we successfully identified key factors influencing the acute inflammatory response, i.e., the initial number of endothelial cells, the chemotaxis threshold, and the level of chemoattractants.

Conclusion

Our findings highlight the pivotal role of the initial endothelial cell count as a key parameter for intensity of inflammation and progression of acute inflammation, 0 - 4 days post-burn.

Burn Injury-related Growth Factor Expressions and Their Potential Roles in Burn-related Neuropathies

In the context of burn injury, growth factors (GFs) play a significant role in mediating the complex local and systematic processes that occur. Among the many systemic complications that arise following a burn injury, peripheral neuropathy remains one of the most common. Despite the broad understanding of the effects GFs have on multiple tissues, their potential implications in both wound healing and neuropathy remain largely unexplored. Therefore, this review aims to investigate the expression patterns of GFs prominent during the burn wound healing process and explore the potential contributions these GFs have on the development of burn-related peripheral neuropathy.

Systemic immune response of burns from the acute to chronic phase

Immune responses that occur following burn injury comprise a series of reactions that are activated in response to damaged autologous tissues, followed by removal of damaged tissues and foreign pathogens such as invading bacteria, and tissue repair. These immune responses are considered to be programmed in living organisms. Developments of modern medicine have led to the saving of burned patients who could not be cured previously; however, the programmed response is no longer able to keep up, and various problems have arisen. This paper describes the mechanism of immune response specific to burn injury and the emerging concept of persistent inflammation, immunosuppression, and catabolism syndrome.