Severe Altered Immune Status After Burn Injury Is Associated With Bacterial Infection and Septic Shock

Phage Therapy in a Burn Patient Colonized with Extensively Drug-Resistant Pseudomonas aeruginosa Responsible for Relapsing Ventilator-Associated Pneumonia and Bacteriemia

Pseudomonas aeruginosa is one of the main causes of healthcare-associated infection in Europe that increases patient morbidity and mortality. Multi-resistant pathogens are a major public health issue in burn centers. Mortality increases when the initial antibiotic treatment is inappropriate, especially if the patient is infected with P. aeruginosa strains that are resistant to many antibiotics. Phage therapy is an emerging option to treat severe P. aeruginosa infections. It involves using natural viruses called bacteriophages, which have the ability to infect, replicate, and, theoretically, destroy the P. aeruginosa population in an infected patient. We report here the case of a severely burned patient who experienced relapsing ventilator-associated pneumonia associated with skin graft infection and bacteremia due to extensively drug-resistant P. aeruginosa. The patient was successfully treated with personalized nebulized and intravenous phage therapy in combination with immunostimulation (interferon-γ) and last-resort antimicrobial therapy (imipenem-relebactam).

Prediction of immune molecules activity during burn wound healing among elderly patients: in-silico analyses: experimental research

Introduction

Burn injuries lead to dysregulation of immune molecules, impacting cellular and humoral immune pathways. This study aims to determine the prediction of immune molecule activity during burn wound healing among elderly patients.

Methods

The current study utilized the Gene Expression Omnibus (GEO) database to extract the proper gene set. Also, the literature review was conducted in the present study to find immune signatures. The study used the "enrich r" website to identify the biological functions of extracted genes. The critical gene modules related to mortality were identified using the weighted gene co-expression network analysis (WGCNA) R package.

Results

The appreciated GSE was extracted. According to the data, the most upregulated signatures were related to natural killer (NK) cells, and the most downregulated signatures were associated with M1 macrophages. Also, the results of WGCNA have shown that the most related gene modules (P<107 and score 0.17) to mortality were investigated, and the modules 100 first genes were extracted. Additionally, the enrich r analysis has demonstrated related pathways, including the immune process, including regulation of histamine secreted from mast cell (P<0.05), T helper 17 cell differentiation (P<0.05), and autophagy (P<0.05) were obtained. Finally, by network analysis, the critical gene "B3GNT5" were obtained (degree>ten and "betweenness and centrality">30 were considered).

Conclusion

The study identified significant changes in macrophage and NK cell expression patterns post-burn injury, linking them to potential improvements in clinical outcomes and wound healing. The gene B3GNT5, associated with mortality, was highlighted as a key marker for prognostic evaluation.

Severe thermal and major traumatic injury results in elevated plasma concentrations of total heme that are associated with poor clinical outcomes and systemic immune suppression

Background

Traumatic and thermal injuries result in a state of systemic immune suppression, yet the mechanisms that underlie its development are poorly understood. Released from injured muscle and lysed red blood cells, heme is a damage associated molecular pattern with potent immune modulatory properties. Here, we measured plasma concentrations of total heme in over 200 traumatic and thermally-injured patients in order to examine its relationship with clinical outcomes and post-injury immune suppression.

Methods

Blood samples were collected from 98 burns (≥15% total body surface area) and 147 traumatically-injured (injury severity score ≥8) patients across the ultra-early (≤1 hour) and acute (4-72 hours) post-injury settings. Pro-inflammatory cytokine production by lipopolysaccharide (LPS) challenged whole blood leukocytes was studied, and plasma concentrations of total heme, and its scavengers haptoglobin, hemopexin and albumin measured, alongside the expression of heme-oxygenase-1 (HO-1) in peripheral blood mononuclear cells (PBMCs). LPS-induced tumour necrosis factor-alpha (TNF-α) production by THP-1 cells and monocytes following in vitro heme treatment was also examined.

Results

Burns and traumatic injury resulted in significantly elevated plasma concentrations of heme, which coincided with reduced levels of hemopexin and albumin, and correlated positively with circulating levels of pro and anti-inflammatory cytokines. PBMCs isolated from trauma patients 4-12 and 48-72 hours post-injury exhibited increased HO-1 gene expression. Non-survivors of burn injury and patients who developed sepsis, presented on day 1 with significantly elevated heme levels, with a difference of 6.5 µM in heme concentrations corresponding to a relative 52% increase in the odds of post-burn mortality. On day 1 post-burn, heme levels were negatively associated with ex vivo LPS-induced TNF-α and interleukin-6 production by whole blood leukocytes. THP-1 cells and monocytes pre-treated with heme exhibited significantly reduced TNF-α production following LPS stimulation. This impairment was associated with decreased gene transcription, reduced activation of extracellular signal-regulated kinase 1/2 and an impaired glycolytic response.

Conclusions

Major injury results in elevated plasma concentrations of total heme that may contribute to the development of endotoxin tolerance and increase the risk of poor clinical outcomes. Restoration of the heme scavenging system could be a therapeutic approach by which to improve immune function post-injury.

Development and validation of a nomogram for pneumonia risk in burn patients with inhalation injury: a multicenter retrospective cohort study

BACKGROUND

Burn patients with inhalation injury are at higher risk of developing pneumonia, and yet there is no reliable tool for the assessment of the risk for such patients at admission. This study aims to establish a predictive model for pneumonia risk for burn patients with inhalation injury based on clinical findings and laboratory tests.

METHOD

This retrospective study enrolled 546 burn patients with inhalation injury. They were grouped into a training cohort and a validation cohort. The least absolute shrinkage and selection operator (LASSO) regression analysis and binary logistic regression analysis were utilized to identify risk factors for pneumonia. Based on the factors, a nomogram for predicting pneumonia in burn patients with inhalation injury was constructed. Areas under the receiver operating characteristic curves (AUC), calibration plots, and decision curve analysis (DCA) were used to evaluate the efficiency of the nomogram in both the training and validation cohorts.

RESULTS

The training cohort included 432 patients, and the validation cohort included 114 patients, with a total of 225 (41.2%) patients experiencing pneumonia. Inhalation injury, tracheal intubation/tracheostomy, low serum albumin, and high blood glucose were independent risk factors for pneumonia in burn patients with inhalation injury and they were further used to build the nomogram. The AUC of the nomogram in the training and validation cohorts were 0.938 (95% CI: 0.917-0.960) and 0.966 (95% CI: 0.931-1), respectively. The calibration curve for probability of pneumonia showed optimal agreement between the prediction by nomogram and the actual observation, and the DCA indicated that the constructed nomogram conferred high clinical net benefit.

CONCLUSION

This nomogram can accurately predict the risk of developing pneumonia for burn patients with inhalation injury, and help professionals to identify high-risk patients at an early stage as well as to make informed clinical decisions.

Microbial infections in burn patients

Polymicrobial infections are the leading causes of complications incurred from injuries that burn patients develop. Such patients admitted to the hospital have a high risk of developing hospital-acquired infections, with longer patient stays leading to increased chances of acquiring such drug-resistant infections. Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis are the most common multidrug-resistant (MDR) Gram-negative bacteria identified in burn wound infections (BWIs). BWIs caused by viruses, like Herpes Simplex and Varicella Zoster, and fungi-like Candida spp. appear to occur occasionally. However, the preponderance of infection by opportunistic pathogens is very high in burn patients. Variations in the causative agents of BWIs are due to differences in geographic location and infection control measures. Overall, burn injuries are characterized by elevated serum cytokine levels, systemic immune response, and immunosuppression. Hence, early detection and treatment can accelerate the wound-healing process and reduce the risk of further infections at the site of injury. A multidisciplinary collaboration between burn surgeons and infectious disease specialists is also needed to properly monitor antibiotic resistance in BWI pathogens, help check the super-spread of MDR pathogens, and improve treatment outcomes as a result.

The Different Shades of Thermogenic Adipose Tissue

PURPOSE OF REVIEW

By providing a concise overview of adipose tissue types, elucidating the regulation of adipose thermogenic capacity in both physiological contexts and chronic wasting diseases (a protracted hypermetabolic state that precipitates sustained catabolism and consequent progressive corporeal atrophy), and most importantly, delving into the ongoing discourse regarding the role of adipose tissue thermogenic activation in chronic wasting diseases, this review aims to provide researchers with a comprehensive understanding of the field.

RECENT FINDINGS

Adipose tissue, traditionally classified as white, brown, and beige (brite) based on its thermogenic activity and potential, is intricately regulated by complex mechanisms in response to exercise or cold exposure. This regulation is adipose depot-specific and dependent on the duration of exposure. Excessive thermogenic activation of adipose tissue has been observed in chronic wasting diseases and has been considered a pathological factor that accelerates disease progression. However, this conclusion may be confounded by the detrimental effects of excessive lipolysis. Recent research also suggests that such activation may play a beneficial role in the early stages of chronic wasting disease and provide potential therapeutic effects. A more comprehensive understanding of the changes in adipose tissue thermogenesis under physiological and pathological conditions, as well as the underlying regulatory mechanisms, is essential for the development of novel interventions to improve health and prevent disease.

Monocyte HLA-DR level on admission predicting in-hospital mortality rate in exertional heatstroke: A 12-year retrospective study

BACKGROUND

Exertional heatstroke (EHS), a fatal illness, pronounces multiple organ dysfunction syndrome (MODS) and high mortality rate. Currently, no ideal factor prognoses EHS. Decreased monocyte human leukocyte-DR antigen (mHLA-DR) has been observed in critically ill individuals, particularly in those with sepsis. While most research focus on the pro-inflammatory response exploration in EHS, there are few studies related to immunosuppression, and no report targeted on mHLA-DR in EHS. The present study tried to explore the prognostic value of mHLA-DR levels in EHS patients.

METHODS

This was a single-center retrospective study. Clinical data of EHS patients admitted to the intensive care unit of the General Hospital of Southern Theatre Command between January 1, 2008, and December 31, 2020, were recorded and analyzed.

RESULTS

Seventy patients with 54 survivors and 16 nonsurvivors were ultimately enrolled. Levels of mHLA-DR in the nonsurvivors (41.8% [38.1-68.1]%) were significantly lower than those in the survivors (83.1% [67.6-89.4]%, p < 0.001). Multivariate logistic regression indicated that mHLA-DR (odds ratio [OR] = 0.939; 95% confidence interval [CI]: 0.892-0.988; p = 0.016) and Glasgow coma scale (GCS) scores (OR = 0.726; 95% CI: 0.591-0.892; p = 0.002) were independent risk factors related with in-hospital mortality rate in EHS. A nomogram incorporated mHLA-DR with GCS demonstrated excellent discrimination and calibration abilities. Compared to the traditional scoring systems, the prediction model incorporated mHLA-DR with GCS had the highest area under the curve (0.947, 95% CI: [0.865-0.986]) and Youden index (0.8333), with sensitivity of 100% and specificity of 83.33%, and a greater clinical net benefit.

CONCLUSION

Patients with EHS were at a risk of early experiencing decreased mHLA-DR early. A nomogram based on mHLA-DR with GCS was developed to facilitate early identification and timely treatment of individuals with potentially poor prognosis.

Acute kidney injury in patients with burns

Burn injury is associated with a high risk of acute kidney injury (AKI) with a prevalence of AKI among patients with burns of 9-50%. Despite an improvement in burn injury survival in the past decade, AKI in patients with burns is associated with an extremely poor short-term and long-term prognosis, with a mortality of >80% among those with severe AKI. Factors that contribute to the development of AKI in patients with burns include haemodynamic alterations, burn-induced systemic inflammation and apoptosis, haemolysis, rhabdomyolysis, smoke inhalation injury, drug nephrotoxicity and sepsis. Early and late AKI after burn injury differ in their aetiologies and outcomes. Sepsis is the main driver of late AKI in patients with burns and late AKI has been associated with higher mortality than early AKI. Prevention of early AKI involves correction of hypovolaemia and avoidance of nephrotoxic drugs (for example, hydroxocobalamin), whereas prevention of late AKI involves prevention and early recognition of sepsis as well as avoidance of nephrotoxins. Treatment of AKI in patients with burns remains supportive, including prevention of fluid overload, treatment of electrolyte disturbance and use of kidney replacement therapy when indicated.

Global burden of burns and its association with socio-economic development status, 1990-2019

BACKGROUND

Burns represent important global health problems. Whereas many studies are limited by the difficulties in estimating the burden of burns and instead focus on the causes of burns, such as fire, heat, and hot substances. Therefore, a complete assessment of the burden of all injuries leading to burns is essential to developing reasonable global intervention strategies.

METHODS

Data on three classes of burns, including "< 20 % total burned surface area without lower airway burns" (Moderate injury), "> =20 % total burned surface area or > = 10 % burned surface area if head/neck or hands/wrist involved w/o lower airway burns" (Major injury), "Lower airway burns" (Inhalation injury) were collected from the Global Burden of Disease 2019 database. Age-standardized incidence rates (ASR-I) and Years Lived with Disability (ASR-YLDs) for burns has been standardized by removing the influence of population size and age structure. They were extracted and stratified by cause, year, sex, age, socio-demographic index, country, and territory.

RESULTS

In terms of ASR-I and ASR-YLDs, burns showed a significant decrease from 1990 to 2019, especially for moderate and major injury. In 2019, the burden of moderate injury was positively correlated with socio-demographic index while major injury was negatively correlated (P < 0.05). We found no correlation between socio-demographic index and the burden for inhalation injury (P > 0.05). Fire, heat, and hot substances were the most important cause of burns except for inhalation injury. The most common association with inhalation injury was falls, which were also a major cause of moderate and major injury.

CONCLUSIONS

The Global Burden of Disease 2019 database data can be used to guide the allocation of resources to reduce ASR-I and ASR-YLDs of different burn classes.

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.

Bioinformatics-Led Identification of Potential Biomarkers and Inflammatory Infiltrates in Burn Injury

Burn injury is a life-threatening disease with a poor prognosis. The immune change and underlying mechanisms remain largely unknown. Thus, this study aims to find potential biomarkers and analyze the immune infiltrates after burn injury. Gene expression data of burn patients were obtained from the Gene Expression Omnibus database. Key immune-related genes (IRGs) were screened by differential and least absolute shrinkage and selection operator (LASSO) regression analysis. Based on key IRGs, patients were divided into two clusters by consensus cluster analysis. Immune infiltration was analyzed by the single sample gene set enrichment analysis (GSEA) method and the immune score was calculated by the principal component analysis method. A nomogram model was constructed based on the calculated immune score and clinical features. Finally, the expression of screened key genes was validated by an external cohort and quantitative polymerase chain reaction experiment. Fifty-nine IRGs were differently expressed in burn patients. After LASSO regression analysis, 12 key genes remained, namely AZU1, OLR1, RNASE2, FGF13, NR1D2, NR2E1, TLR5, CAMP, DEFA4, PGLYRP1, CTSG, and CCR3. Then, patients were divided into two clusters. Immune infiltration analysis revealed that more immune cells were infiltrated and more pathways were activated in cluster A, in which patients showed high immune scores. Finally, a nomogram model was constructed and showed high accuracy and reliability. The expression pattern of 12 key genes in an external cohort and clinical samples was in accordance with the theoretical analysis results. In conclusion, this research elucidated the key role of immune response in burns and could be used as a guide for burn treatment.

Multifunctional MXene-Based Bioactive Materials for Integrated Regeneration Therapy

The reconstruction engineering of tissue defects accompanied by major diseases including cancer, infection, and inflammation is one of the important challenges in clinical medicine. The development of innovative tissue engineering strategies such as multifunctional bioactive materials presents a great potential to overcome the challenge of disease-impaired tissue regeneration. As the major representative of two-dimensional nanomaterials, MXenes have shown multifunctional physicochemical properties and have been diffusely studied as multimodal nanoplatforms in the field of biomedicine. This review summarized the recent advances in the multifunctional properties of MXenes and integrated regeneration-therapy applications of MXene-based biomaterials, including tissue regeneration-tumor therapy, tissue regeneration-infection therapy, and tissue regeneration-inflammation therapy. MXenes have been recognized as good candidates for promoting tissue regeneration and treating diseases through photothermal therapy, regulating cell behavior, and drug and gene delivery. The current challenges and future perspectives of MXene-based biomaterials in integrated regeneration-therapy are also discussed well in this review. In summary, MXene-based biomaterials have shown promising potential for integrated tissue regeneration and disease treatment due to their favorable physicochemical properties and bioactive functions. However, there are still many obstacles and challenges that must be addressed for the regeneration-therapy applications of MXene-based biomaterials, including understanding the bioactive mechanism, ensuring long-term biosafety, and improving their targeting therapy capacity.

Tranexamic acid in burn surgery: A systematic review and meta-analysis

Burn injury causes a coagulopathy that is poorly understood. After severe burns, significant fluid losses are managed by aggressive resuscitation that can lead to hemodilution. These injuries are managed by early excision and grafting, which can cause significant bleeding and further decrease blood cell concentration. Tranexamic acid (TXA) is an anti-fibrinolytic that has been shown to reduce surgical blood losses; however, its use in burn surgery is not well established. We performed a systematic review and meta-analysis to investigate the influence TXA may have on burn surgery outcomes. Eight papers were included, with outcomes considered in a random-effects model meta-analysis. Overall, when compared to the control group, TXA significantly reduced total volume blood loss (mean difference (MD) = -192.44; 95% confidence interval (CI) = -297.73 to - 87.14; P = 0.0003), the ratio of blood loss to burn injury total body surface area (TBSA) (MD = -7.31; 95% CI = -10.77 to -3.84; P 0.0001), blood loss per unit area treated (MD = -0.59; 95% CI = -0.97 to -0.20; P = 0.003), and the number of patients receiving a transfusion intraoperatively (risk difference (RD) = -0.16; 95% CI = -0.32 to - 0.01; P = 0.04). Additionally, there were no noticeable differences in venous thromboembolism (VTE) events (RD = 0.00; 95% CI = -0.03 to 0.03; P = 0.98) and mortality (RD = 0.00; 95% CI = -0.03 to 0.04; P = 0.86). In conclusion, TXA can potentially be a pharmacologic intervention that reduces blood losses and transfusions in burn surgery without increasing the risk of VTE events or mortality.

Predictive value of perioperative peripheral blood cells counts for bacteremia and 90-day mortality in severe burn patients

OBJECTIVE

Burn bacteremia is related to immune barrier damage, but whether the level of circulating immune cells predicts outcomes in severe burns is still not clear. This study aimed to explore the predictive value of perioperative blood cells of the first surgery after burn for bacteremia and 90-day death.

METHODS

Data from severe burn patients treated at the First Affiliated Hospital of Sun Yat-sen University from 2011 to 2020 were retrospectively analyzed. Data on monocytes (M), lymphocytes (L), white blood cell-to-platelet ratio (WPR), neutrophil-to-lymphocyte ratio (NLR) in peripheral blood and changes in temperature (T-37) were collected at one day before(X0), the first day after (X1) and the third day after (X3) the primary surgery.Univariate and multivariate logistic regression were used to identify the independent risk factors of bacteremia and death within 90 days, which were used to establish the risk prediction models (xbac and x90d-m) in severely burned patients. Severe burn cases from two other burn centers were selected to verify the prediction models.

RESULTS

We analyzed 169 severe burn cases in the training dataset, with a 90-day mortality of 21.3% (36/169); 56 (33.1%) patients experienced burn bacteremia. Higher M0, WPR0, NLR0, NLR3, T3-37, ∆M (M0-M3) and lower M3, L3 were associated with higher risk of bacteremia (P < 0.05). Multivariate regression analysis showed that SOFA0, WPR0, M3, and T3-37 were independently associated with bacteremia. The prediction model for bacteremia Xbac = 0.1809 × SOFA0 + 6.532 × WPR0-1.171 × M3 + 0.6987 × T3-37- 2.297. TBSAB, SOFA0, and ∆M (M0-M3) were independently correlated with 90-day mortality. The risk prediction model X90d-m= 0.055 × TBSAB + 0.301 ×SOFA0 + 1.508 × ∆M - 7.196. External validation suggested that the specificity, sensitivity and AUC of the prediction model Xbac was 90.7%, 62.5% and 0.797, respectively; of the prediction model X90d-m was 69.2%, 90.0% and 0.873, respectively.

CONCLUSION

Peripheral M3, WPR0 and ∆M (M0-M3) during the primary surgery has reasonable predictive ability for bacteremia and 90-day mortality in severe burn patients, which could inform clinical antimicrobial judgment and prognostication.

Acute muscle mass loss was alleviated with HMGB1 neutralizing antibody treatment in severe burned rats

Burn injury is associated with muscle wasting, though the involved signaling mechanisms are not well understood. In this study, we aimed to examine the role of high mobility group box 1 (HMGB1) in signaling hyper-inflammation and consequent skeletal muscle impairment after burn. Sprague Dawley rats were randomly assigned into three groups: (1) sham burn, (2) burn, (3) burn/treatment. Animals in group 2 and group 3 received scald burn on 30% of total body surface area (TBSA) and immediately treated with chicken IgY and anti-HMGB1 antibody, respectively. Muscle tissues and other samples were collected at 3-days after burn. Body mass and wet/dry weights of the hind limb muscles (total and individually) were substantially decreased in burn rats. Acute burn provoked the mitochondrial stress and cell death and enhanced the protein ubiquitination and LC3A/B levels that are involved in protein degradation in muscle tissues. Further, an increase in muscle inflammatory infiltrate associated with increased differentiation, maturation and proinflammatory activation of bone marrow myeloid cells and αβ CD4+ T and γδ T lymphocytes was noted in in circulation and spleen of burn rats. Treatment with one dose of HMGB1 neutralizing antibody reduced the burn wound size and preserved the wet/dry weights of the hind limb muscles associated with a control in the markers of cell death and autophagy pathways in burn rats. Further, anti-HMGB1 antibody inhibited the myeloid and T cells inflammatory activation and subsequent dysregulated inflammatory infiltrate in the muscle tissues of burn rats. We conclude that neutralization of HMGB1-dependent proteolytic and inflammatory responses has potential beneficial effects in preventing the muscle loss after severe burn injury.

Aberrant inflammatory responses in intoxicated burn-injured patients parallel impaired cognitive function

Burn-injured patients with alcohol use disorder (AUD) have increased morbidity and mortality compared to alcohol-abstaining individuals with similar injuries. It is hypothesized that this is due, in part, to alcohol-induced dysregulation of the systemic inflammatory response, leading to worsened clinical outcomes, including increased susceptibility to infection, and heightened cognitive impairment. To examine the effects of alcohol on inflammatory markers after burn injury, we used multiplex assays to measure a panel of 48 cytokines, chemokines, and growth factors in the plasma of burn patents within 24 h of admission to the University of Colorado Burn Center. Thirty patients were enrolled between July 2018 to February 2020 and were stratified based on presence of AUD and total body surface area (TBSA) burn of ≥20% into four groups: [AUD-, TBSA <20%, N = 12], [AUD+, TBSA <20%, N = 3], [AUD-, TBSA ≥20%, N = 8], [AUD+, TBSA ≥20%, N = 7]. In addition, Confusion Assessment Method (CAM) scores were collected to evaluate patient delirium during the course of hospitalization. Multivariate statistical analysis demonstrated a number of cytokines and other factors that were significantly different between the groups. For example, the anti-inflammatory cytokine interleukin 1 receptor antagonist (IL-1ra) was dampened in the AUD+, TBSA ≥20% cohort with a 75.2% decrease compared to AUD-, TBSA ≥20%, and an 83.9% decrease compared to AUD-, TBSA <20% (p = 0.008). Additionally, plasma levels of the pro-inflammatory mediator CXCL12 (C-X-C motif chemokine ligand 12, also known as stromal cell-derived factor 1, SDF-1) was higher in the AUD + groups (p = 0.03) and similarly, IL-18 levels were greater in AUD+, TBSA ≥20% (p = 0.009). Eotaxin (also known as cytokine CC motif ligand 11, CCL11) was markedly elevated in the AUD+, TBSA ≥20% cohort with a 2.4-fold increase over the AUD-, TBSA ≥20%, and a 1.7-fold rise compared to the AUD-, TBSA <20% cohorts (p = 0.04). Interestingly, there was also a marked rise in CAM + delirium scores (85.7%) among the AUD + patients with TBSA ≥20% (p = 0.02). Not surprisingly, we found that hospital stays increased with AUD+ and larger burns (p = 0.0009). Our findings reveal that burn patients who misuse alcohol have aberrant inflammatory responses that may lead to greater immune dysregulation and worse clinical outcomes.

Study on immune status alterations in patients with sepsis

Sepsis, characterized by cytokine-mediated hyper-inflammation and a consistent decline in immune responsiveness, is associated with a high risk of death in the intensive care unit (ICU). Here, we for the first time investigated the changes in immune and inflammatory responses to understand the interactions between immune and inflammatory biomarkers and their association with patient outcomes. The cytokine and lymphocyte subset levels were analyzed in healthy donors (HD) and patients with sepsis upon admission to the ICU (D0), D3, D7, D14, and D28 using flow cytometry. The primary endpoint was mortality on day 90. The trends in lymphocyte subsets and cytokine levels in all patients (n = 47), HD (n = 27), and patient subgroups (surviving, n = 30; dead, n = 17) were analyzed using an independent sample t-test and principal component analysis. Age, steroids (steroids used > 48 h), secondary infection, acute heart failure, acute kidney injury, coagulopathy, hypohepatia, organ transplant and septic shock (when transferred to the ICU) were associated with mortality. Absolute lymphocyte counts and lymphocyte subsets levels were reduced in most patients with sepsis. The proportion of Tregs in the patients increased with disease progression and was associated with immunosuppression. In conclusion, sepsis downregulated adaptive immunity, and induced the transition of the patients to prolonged immune suppression. The study suggests that while cellular immunity recovered within 2 weeks of admission, humoral and innate immunity recovery takes longer. These findings may assist in developing appropriate therapeutic approaches to improve the immune responses in patients with sepsis.

DEMOGRAPHICS TO DEFINE PEDIATRIC BURN PATIENTS AT RISK OF ADVERSE OUTCOMES

ABSTRACT

Background: There is currently no standard definition of a severe burn in the pediatric patient population to identify those at higher risk of infectious complications. Our aim was to correlate total burn surface area (TBSA), burn depth, and type of burn injury to nosocomial infection rates and systemic immune system responses to better define risk factors associated with adverse outcomes. Methods: A prospective observational study at a single-center, quaternary-care, American Burn Association-verified pediatric burn center was conducted from 2016 to 2021. Blood was collected within 72 h of injury from 103 pediatric patients. Whole blood was incubated with lipopolysaccharide or phytohemagglutinin stimulation reagent to measure innate and adaptive immune response, respectively. Flow cytometry was performed on whole blood samples to measure both innate and adaptive immune cells. Unstimulated plasma was also extracted, and IL-6 and IL-10 as well as soluble proteins B- and T-lymphocyte attenuator, CD27, and T-cell immunoglobulin mucin 3 were quantified. Results: There was a significant increased risk for nosocomial infection in pediatric patients with TBSA burns of ≥20%, full-thickness burn injuries ≥5%, or flame burn injuries. There was an overall decrease in both innate and adaptive immune function in patients with TBSA burns ≥20% or full-thickness burn injuries ≥5%. Both burn injury characteristics were also associated with a significant increase in unstimulated IL-6 and IL-10 and soluble immunoregulatory checkpoint proteins. We observed a significant decrease in soluble B- and T-lymphocyte attenuator for those with a flame injury, but there were no other differences between flame injury and scald/contact burns in terms of innate and adaptive immune function. Conclusion: Burns with ≥20% TBSA or ≥5% full thickness in pediatric patients are associated with systemic immune dysfunction and increased risk of nosocomial infections.

Icy core-shell composite nanofibers with cooling, antibacterial and healing properties for outdoor burns

Burns are usually difficult to treat because their susceptibe to bacterial infections. When burns is accompanied by hyperthermia, the heat accumulated on the skin will causes extensive tissue damage. Most dressings focus on the treatment process, while ignoring the first-aid treatment to remove hyperthermia. To make matters worse, when outdoors, it is hard to find clean water to wash and cool the burned area. A dressing which can simultaneously realize first-time cooling and repairing treatment of the burned area can shorten treatment time, and is especially beneficial for outdoor use. In this study, a handheld coaxial electrospinning device is developed for preparing platelet-rich plasma @Polycaprolactone-epsilon polylysine (PRP@PCL/ε-PL) core-shell nanofibers. The nanofibers can be synchronously transformed into ice fibers during the spinning process, and directly deposited on the skin. The whole process is convenient to use outdoor. Via dual cooling mechanisms, first aid can take away the excessive heat in the burn area by nanofibers. These core-shell nanofibers also show its excellent antimicrobial and tissue regeneration-promoting properties. Therefore, it achieves first-time cooling and repair treatment of the burned area at the same time. Moreover, due to direct in-situ deposition of this handheld coaxial electrospinning, better antimicrobial properties, and faster healing performance are achieved. By using this integrated strategy that combines cooling, antibacterial and healing promotion, the burn recovery time is shortened from 21 days to 14 days.

Targeted multi-omic analysis of human skin tissue identifies alterations of conventional and unconventional T cells associated with burn injury

Burn injuries are a leading cause of unintentional injury, associated with a dysfunctional immune response and an increased risk of infections. Despite this, little is known about the role of T cells in human burn injury. In this study, we compared the activation and function of conventional T cells and unconventional T cell subsets in skin tissue from acute burn (within 7 days from initial injury), late phase burn (beyond 7 days from initial injury), and non-burn patients. We compared T cell functionality by a combination of flow cytometry and a multi-omic single-cell approach with targeted transcriptomics and protein expression. We found a significantly lower proportion of CD8+ T cells in burn skin compared to non-burn skin, with CD4+ T cells making up the bulk of the T cell population. Both conventional and unconventional burn tissue T cells show significantly higher IFN-γ and TNF-α levels after stimulation than non-burn skin T cells. In sorted T cells, clustering showed that burn tissue had significantly higher expression of homing receptors CCR7, S1PR1, and SELL compared to non-burn skin. In unconventional T cells, including mucosal-associated invariant T (MAIT) and γδ T cells, we see significantly higher expression of cytotoxic molecules GZMB, PRF1, and GZMK. Multi-omics analysis of conventional T cells suggests a shift from tissue-resident T cells in non-burn tissue to a circulating T cell phenotype in burn tissue. In conclusion, by examining skin tissue from burn patients, our results suggest that T cells in burn tissue have a pro-inflammatory rather than a homeostatic tissue-resident phenotype, and that unconventional T cells have a higher cytotoxic capacity. Our findings have the potential to inform the development of novel treatment strategies for burns.

Immune reactivity features in post-burn dynamics

Relevance. To date, burn injury remains a complex type of damage to skin tissues. Along with local destructive and dystrophic phenomena, systemic changes in the body are observed. The aim of the study was the experimental study of the immune reactivity of the body of nonlinear rats under conditions of “burn” stress formed as a result of contact thermal trauma. Materials and Methods. The study was carried out on non-linear male rats with an average mass of 220 gr. The functional activity of the immune system of laboratory animals was evaluated on the basis of standard tests assessing the adaptability of the immune system. Results and Discussion. In an experimental study, it was found that in the dynamics of burn injury in laboratory animals, variable changes in the body’s immune reactivity were observed at the level of the cellular and humoral links of immunity, which was manifested by a decrease in the WGST index and an increase in the following indicators - antibody titer, phagocytic index (FI), phagocytic number (FF), leukocytic coefficient and number of leukocytes. The increased content of stick-n uclear forms indicated the activation of granulocytopoiesis, which determined the deregenerative nuclear shift of neutrophil granulocytes to the left. Along with these changes, a decrease in the mass of immune organs (thymus and spleen) was observed, which can be explained by the expression of accidental involution caused by intoxication against the background of a thermal burn. Conclusion. Under conditions of “burn” stress, an immune imbalance occurs in the form of activation of some and suppression of other links at different observation times. Thus, during the burn process, systemic immune changes taking place at the body level have a multi-d irectional dynamic character, which indicates the adaptive capabilities of the immune system.

Modern aspects of burn injury immunopathogenesis and immuno-biochemical markers of wound healing (review of literature)

Burns are one of the most common traumatic injuries in the world, representing a global public health problem. Major burns (severe burn injury or burn disease) are one of the most life-threatening injuries. There is a great need to identify and monitor the development of complications (sepsis and septic shock, coagulopathy and DIC) in burned patients. The basis of the pathogenesis of burn injury, as well as any general pathological process, is an inflammatory reaction, ultimately aimed at restoring the structure and function of the damaged tissue. A feature of the inflammatory reaction in burn injury is the scale of alteration of the skin and mucous membranes. The review presents the main aspects of the burn injuries immunopathogenesis and the features of post-burn immune dysfunction, manifested by disorders in the innate and adaptive immunity systems. Attention is focused on the role in the immunopathogenesis of developing systemic and local disorders in burn injury. Also the role are discussed of a minor subpopulations of lymphocytes (Treg-, Th-17-, γδT-cells) in the immunopathogenesis and in the bacterial infection protection. The characteristics of the main immuno-biochemical markers of burn injury (cytokines and growth factors, nitric oxide, matrix metalloproteases, bacteria concentration levels) are present. The prognostic role of these biomarkers in assessing of the severity degree of patients with burn injury and wound healing processes is shown. The review has been compiled using references from major databases such as RSCI, Web of Science, PubMed, Scopus and Google Scholar (up to march 2022). After obtaining all reports from database, the papers were carefully analyzed in order to find data related to the topic of this review (60 references).

Temporal trends, predictors of blood transfusion and in-hospital outcomes among patients with severe burn injury in the United States-A national database-based analysis

BACKGROUND

Severe burn can be accompanied by life-threatening bleeding on some occasions, thus, blood transfusion is often required in these patients during their hospitalization. Therefore, we aimed to examine temporal trends, predictors, and in-hospital outcomes of blood transfusion in these patients in the United States.

METHODS

The National Inpatient Sample was used to identify severe burn patients between January 2010 and September 2017 in the United States. Trends in the utilization of blood transfusion were analyzed using the Cochran-Armitage trend test. Moreover, propensity score matching (PSM) was employed, and then in-hospital outcomes were compared between these two groups in the matched cohort. Multivariable logistic regressions were further used to validate the results of PSM.

RESULTS

Among 27,260 severe burn patients identified during the study period, 2120 patients (7.18%) received blood transfusion. Blood transfusion rates decreased significantly from 9.52% in 2010 to 5.02% in 2017 (p for trend <.001). In the propensity-matched cohort (2120 pairs with and without transfusion), patients transfused were at increased risk of in-hospital mortality (13.3% vs 8.77%, p < .001), overall postoperative complications (88.3% vs 72.59%, p < .001), longer hospital stays (defined as > median hospital stays = 5 d) (73.8% vs 50.6%, p < .001) and increased overall cost (defined as > median overall costs = 30,746) (81.6% vs 57.3%, p < .001). This was also the case for the multivariable analysis.

CONCLUSIONS

Blood transfusion following severe burn injury may be associated with worse clinical outcomes. The utility for blood transfusion in burn patients warrants further prospective exploration.

Modern Aspects of Burn Injury Immunopathogenesis and Prognostic Immunobiochemical Markers (Mini-Review)

Burn injuries are among the most common peacetime injuries, with mortality ranging from 2.3% to 3.6%. At the same time, 85–90% of patients with burns are people of working age and children. Burn injury leads to metabolic disorders and systemic inflammatory response, inefficient energy consumption, and other physiological changes that can lead to dysfunction of organs and systems. The most formidable complication of burn injuries is sepsis mediated by multiple organ failure, the most common cause of poor prognosis in patients and has specific differences in these injuries. The purpose of this article was to dwell in detail on the most promising immunobiochemical markers of sepsis in the format of a mini-review, based on the main aspects of the immunopathogenesis of this complication. The pathogenesis of a burn injury and any general pathological process is based on an inflammatory reaction and large-scale changes in the skin and mucous membranes. This review is devoted to the progress in understanding the main aspects of the immunopathogenesis of burn lesions and the features of post-burn immune dysfunction, manifested by disorders in the innate and adaptive immunity systems. Attention is focused on the role in the immunopathogenesis of the development of systemic and local disorders in burn injury. Characterization of primary immunobiochemical markers of burn injury (cytokines, growth factors, C-reactive protein, procalcitonin, presepsin, matrix metalloproteinases, reactive oxygen species, nitric oxide, hemostasis parameters) is presented. The problem of treating burn lesions is associated with constant monitoring of the condition of patients and regular monitoring of specific immunobiochemical markers predicting sepsis for the timely initiation of a specific therapy.

The Role of the Immune System in Pediatric Burns: A Systematic Review

Burns are one of the most common causes of home injuries, characterized by serious damage to the skin and causing the death of affected tissues. In this review, we intended to collect information on the pathophysiological effects of burns in pediatric patients, with particular emphasis on local and systemic responses. A total of 92 articles were included in the review, and the time range of the searched articles was from 2000 to 2021. The occurrence of thermal injuries is a problem that requires special attention in pediatric patients who are still developing. Their exposure to various burns may cause disturbances in the immune response, not only in the area of tissue damage itself but also by disrupting the systemic immune response. The aspect of immunological mechanisms in burns requires further research, and in particular, it is important to focus on younger patients as the existence of subtle differences in wound healing between adults and children may significantly influence the treatment of pediatric patients.

sEH-derived metabolites of linoleic acid drive pathologic inflammation while impairing key innate immune cell function in burn injury

Oxylipins alter immune cell function and potentially drive pathophysiology in burn and sepsis patients. Past and recent data reveal a correlation between increased systemic EpOME levels and reduced survival in human burn trauma and sepsis. This work extends these studies and provides evidence that the downstream sEH-derived metabolites, DiHOMEs, are driving worsening outcomes by altering the immune response. Inhibiting DiHOME metabolite formation with the sEH inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), restored immune function by increasing immune cell survival and function. These data support the hypothesis that sEH-derived linoleic acid diols are responsible for increased mortality in burn and sepsis patients and also provide a rationale for testing the therapeutic blockage of DiHOME generation in burn and sepsis patients to improve their outcomes.

Fatty acid composition in the Western diet has shifted from saturated to polyunsaturated fatty acids (PUFAs), and specifically to linoleic acid (LA, 18:2), which has gradually increased in the diet over the past 50 y to become the most abundant dietary fatty acid in human adipose tissue. PUFA-derived oxylipins regulate a variety of biological functions. The cytochrome P450 (CYP450)–formed epoxy fatty acid metabolites of LA (EpOMEs) are hydrolyzed by the soluble epoxide hydrolase enzyme (sEH) to dihydroxyoctadecenoic acids (DiHOMEs). DiHOMEs are considered cardioprotective at low concentrations but at higher levels have been implicated as vascular permeability and cytotoxic agents and are associated with acute respiratory distress syndrome in severe COVID-19 patients. High EpOME levels have also correlated with sepsis-related fatalities; however, those studies failed to monitor DiHOME levels. Considering the overlap of burn pathophysiology with these pathologies, the role of DiHOMEs in the immune response to burn injury was investigated. 12,13-DiHOME was found to facilitate the maturation and activation of stimulated neutrophils, while impeding monocyte and macrophage functionality and cytokine generation. In addition, DiHOME serum concentrations were significantly elevated in burn-injured mice and these increases were ablated by administration of 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), a sEH inhibitor. TPPU also reduced necrosis of innate and adaptive immune cells in burned mice, in a dose-dependent manner. The findings suggest DiHOMEs are a key driver of immune cell dysfunction in severe burn injury through hyperinflammatory neutrophilic and impaired monocytic actions, and inhibition of sEH might be a promising therapeutic strategy to mitigate deleterious outcomes in burn patients.

Severity of thermal burn injury is associated with systemic neutrophil activation

Burn injuries elicit a unique and dynamic stress response which can lead to burn injury progression. Though neutrophils represent crucial players in the burn-induced immunological events, the dynamic secretion pattern and systemic levels of neutrophil-derived factors have not been investigated in detail so far. Serum levels of neutrophil elastase (NE), myeloperoxidase (MPO), citrullinated histone H3 (CitH3), and complement factor C3a were quantified in burn victims over 4 weeks post injury. Furthermore, the potential association with mortality, degree of burn injury, and inhalation trauma was evaluated. In addition, leukocyte, platelet, neutrophil, and lymphocyte counts were assessed. Lastly, we analyzed the association of neutrophil-derived factors with clinical severity scoring systems. Serum levels of NE, MPO, CitH3, and C3a were remarkably elevated in burn victims compared to healthy controls. Leukocyte and neutrophil counts were significantly increased on admission day and day 1, while relative lymphocytes were decreased in the first 7 days post burn trauma. Though neutrophil-derived factors did not predict mortality, patients suffering from 3rd degree burn injuries displayed increased CitH3 and NE levels. Accordingly, CitH3 and NE were elevated in cases with higher abbreviated burn severity indices (ABSI). Taken together, our data suggest a role for neutrophil activation and NETosis in burn injuries and burn injury progression. Targeting exacerbated neutrophil activation might represent a new therapeutic option for severe cases of burn injury.