Determination of Serum Levels of Interleukin-6, Interleukin-8, Interleukin-10, and Tumor Necrosis-Alpha and their Relationship With The Total Body Surface Area in Children

IL-8 Induces Neutrophil Extracellular Trap Formation in Severe Thermal Injury

Neutrophil extracellular traps (NETs) have a dual role in the innate immune response to thermal injuries. NETs provide an early line of defence against infection. However, excessive NETosis can mediate the pathogenesis of immunothrombosis, disseminated intravascular coagulation (DIC) and multiple organ failure (MOF) in sepsis. Recent studies suggest that high interleukin-8 (IL-8) levels in intensive care unit (ICU) patients significantly contribute to excessive NET generation. This study aimed to determine whether IL-8 also mediates NET generation in patients with severe thermal injuries. IL-8 levels were measured in serum samples from thermally injured patients with ≥15% of the total body surface area (TBSA) and healthy controls (HC). Ex vivo NET generation was also investigated by treating isolated neutrophils with serum from thermal injured patients or normal serum with and without IL-8 and anti-IL-8 antibodies. IL-8 levels were significantly increased compared to HC on days 3 and 5 (p < 0.05) following thermal injury. IL-8 levels were also significantly increased at day 5 in septic versus non-septic patients (p < 0.001). IL-8 levels were also increased in patients who developed sepsis compared to HC at days 3, 5 and 7 (p < 0.001), day 10 (p < 0.05) and days 12 and 14 (p < 0.01). Serum containing either low, medium or high levels of IL-8 was shown to induce ex vivo NETosis in an IL-8-dependent manner. Furthermore, the inhibition of DNase activity in serum increased the NET-inducing activity of IL-8 in vitro by preventing NET degradation. IL-8 is a major contributor to NET formation in severe thermal injury and is increased in patients who develop sepsis. We confirmed that DNase is an important regulator of NET degradation but also a potential confounder within assays that measure serum-induced ex vivo NETosis.

The dynamic changes of monocytes and cytokines during wound healing post-burn injury

BACKGROUND

Burn injury is a sudden and traumatic injury that affects a large part of the population worldwide, who are placed at high risk of developing hypertrophic scars (HTS). HTS are a fibrotic scar resulting in painful contracted and raised scarring, affecting mobility in joints and work life, as well as cosmetically. The aim of this research was to enhance our understanding of the systematic response of monocytes and cytokines in wound healing after burn injury, in order to develop novel approaches to prevention and treatment of HTS.

METHODS

Twenty-seven burn patients and thirteen healthy individuals were recruited in this study. Burn patients were stratified by burn total body surface area (TBSA). Peripheral blood samples were taken post-burn injury. Serum and peripheral blood mononuclear cells (PBMCs) were separated from the blood samples. This research investigated cytokines IL-6, IL-8, IL1RA, IL-10, and chemokine pathways SDF-1/CXCR4, MCP-1/CCR2, RANTES/CCR5 during the wound healing process in burn patients with varying severity of injuries by using enzyme-linked immunosorbent assays. PBMCs were stained for monocytes and the chemokine receptors by flow cytometry. Statistical analysis was done by one-way ANOVA with a Tukey correction, and regression analysis was performed using Pearson's Correlation analysis.

RESULTS

The CD14⁺CD16^- monocyte subpopulation is larger in patients who developed HTS at 4-7 days. The CD14⁺CD16⁺ monocyte subpopulation is smaller in the first week of injury, where it is similar after 8 days. Burn injury increased CXCR4, CCR2, and CCR5 expressions in CD14⁺ CD16⁺ monocytes. Increases in MCP-1 at 0-3 days after burn injury was positively correlated with burn severity. IL-6, IL-8, RANTES, and MCP-1 significantly increased with increasing burn severity.

CONCLUSIONS

Monocytes and their chemokine receptors, as well as systemic levels of cytokines in wound healing of burn patients and scar development will require ongoing assessment to enhance our understanding of the abnormal wound healing after burn injury.

Inflammatory response: The target for treating hyperpigmentation during the repair of a burn wound

Hyperpigmentation is a common complication in patients with burn injuries during wound healing; however, the mechanisms underlying its occurrence and development remain unclear. Recently, postinflammatory hyperpigmentation (PIH) was found to result from overproduction of melanin. Local or systemic inflammatory responses are often observed in patients who develop hyperpigmentation. However, we lack studies on the relationship between PIH and burn injury. Therefore, we comprehensively reviewed the existing literature on the melanogenesis of the skin, inflammatory mechanisms in pigmentation, and local or systemic alteration in inflammatory cytokines in patients suffering from burn trauma to elucidate the relationship between PIH and burn injury. We believe that this review will guide further research on regulating melanin production in the burn management process.

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.

Alterations in serum IL-6 levels in traumatized pediatric patients: A preliminary study for second hit concept

BACKGROUND

The inflammatory response of pediatric patients to multiple injuries can be monitored by serum interleukin-6 levels. The aim of this study was to investigate the severity of the inflammatory response accordingly interleukin-6 (IL-6) which have not been evaluated before.

METHODS

There were 30 patients with an isolated long-bone fracture in group 1 and 49 patients with multi-system injury with at least a fracture in group-2. In group-2 were divided into two subgroups according to MISS (cut-off value = 17). Group-3 was composed of 100 healthy children as the control group to determine the normal range of serum IL-6 levels. In group-2, blood samples were taken on the 3rd, 5th, and 10th days, and if the patient was operated, additional samples were taken before the surgery and on the postoperative 1st, 5th, and 10th days. The relationship between trauma severity and serum IL-6 levels was analyzed statistically.

RESULTS

Mean serum IL-6 levels were 16.1, 46.4, 74.2 and 8.6 pg/mL respectively (group-1, -2A, -2B, and -3). There was a moderate correlation between MISS and IL-6 (p < 0.001). In group-2A, mean serum IL-6 levels were 13.9 pg/mL on the 3rd day and 9.1 on the 10th day. In group-2B they were 15.4 and 4.7 pg/mL, respectively. Also, for the patients undergoing surgically in group-2A, they were 36.0 pg/mL before the surgery, 33.2 on the 1st day, and 6.0 on the 10th day. For group-2B, they were 39.3, 37.4, and 7.9 pg/mL, respectively.

CONCLUSION

It was determined that serum IL-6 levels were significantly increased with increasing trauma severity. Systemic inflammation specified by IL-6 could decrease to almost normal on the 3rd day, and regress to normal on the following days. The concept of "second hit impact following surgical procedure" may also be kept in mind in children as in adults considering these alterations.

Efficacy of graphene oxide-loaded cationic antimicrobial peptide AWRK6 on the neutralization of endotoxin activity and in the treatment of sepsis

Objective: This study is to assess the therapeutic effect of graphene oxide (GO) loaded with AWRK6 on endotoxin-induced sepsis.

Method: AWRK6/GO was prepared by GO loaded AWRK6, with the structure characterization of AWRK6/GO conducted by atomic force microscope (AFM) and ultraviolet spectrophotometer, the sustained release rate of AWRK6/GO detected by high performance liquid chromatography (HPLC), and the neutralization ability of AWRK6/GO to lipopolysaccharide (LPS) tested by in vitro experiments. The levels of IL-8 and TNF-α in mouse cells after drug intervention were detected by ELISA; a LPS mouse model was established to observe the effects of drug intervention on the survival cycle and survival rate of mice.

Results: The sustained drug release rate of AWRK6/GO reached 85% within 24 hours observed under in vitro conditions, with an efficient neutralization effect to LPS (P < 0.01); Compared with the control group, the intervention of LPS succeeded in remarkably elevating the levels of IL-8 and TNF-α in the whole blood and macrophages of the mice (P < 0.01), whose survival cycle and survival rate consequently observed an obvious decline (P < 0.01); The intervention with AWRK6 or AWRK6/GO predominantly brought down the levels of IL-8 and TNF-α in the whole blood and macrophages of mice given LPS (P < 0.01), resulting in an elevation of the survival rate and survival time (P < 0.01).

Conclusion: GO loaded with cationic antimicrobial peptide AWRK6 exerts a rosy neutralization effect on endotoxin activity, with no obvious side effects on mice observed, which is of certain application value in the treatment of sepsis.