Eosinophil infiltration of burn wounds in young and older burn patients

Burn wound conversion: clinical implications for the treatment of severe burns

The identification of novel treatments for severe burn wounds relies on accurate clinical assessments of the extent of injury. However, evaluation of burn wound depth can be challenging due to the tendency for burn wounds to progress over time in a little-understood process known as 'burn wound conversion'. Local factors affecting the burn wound, such as inflammation, oxidative stress-induced tissue damage, vasostasis and bacterial infections, lead to increased cell death by apoptosis or oncosis, while systemic events may promote burn wound conversion. Acute shock, metabolic derangements, age or immunomodulation can modify cytokine secretion, lower immune responses, decrease blood flow or cause bacterial infection at the burn wound site. Therefore, therapeutic approaches targeting specific mechanisms that reduce cell death, improve wound reperfusion and promote tissue regrowth should favourably enhance burn wound healing, and long-term functional and aesthetic outcomes. Our current understanding of these mechanisms mostly comes from animal studies, underscoring the need for extensive research in humans. A streamlined approach would be to investigate the parallels in other disease states that exhibit ischaemia and potential reperfusion, such as ischaemic stroke and myocardial infarction. Moreover, in view of the limited knowledge available on the subject, the need exists for further clinical research into burn wound conversion and novel target pathways to ameliorate its effects. This review describes events that affect the viability of cells at the burn wound site resulting in burn wound conversion, and identifies potential targets for clinical interventions that may diminish burn wound conversion.

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.

The Immune System and Its Contribution to Variability in Regenerative Medicine

The immune system plays a critical role in directing tissue repair and regeneration outcomes. Tissue engineering technologies that are designed to promote new tissue growth will therefore be impacted by immune factors that are present in patients both locally at the site of intervention and systemically. The immune state of patients can be influenced by many factors, including infection, nutrition, and other disease comorbidities. As a result, the immune state is highly variable and may be a source of variability in tissue-engineered products in the clinic, which is not found in preclinical models. In this review, we will summarize key immune cells and evidence of their activity in tissue repair and potential in tissue engineering systems. We also discuss how clinical translation of tissue engineering strategies, in particular stem cells, helped elucidate the importance of the immune system. With increased understanding of the immune system's role in repair and tissue engineering systems, it will likely become a therapeutic target and component of future therapies.

Aberrant recruitment of leukocytes defines poor wound healing in patients with recessive dystrophic epidermolysis bullosa

BACKGROUND

Poorly healing wounds are one of the major complications in patients suffering from recessive dystrophic epidermolysis bullosa (RDEB). At present, there are no effective means to analyze changes in cellular and molecular networks occurring during RDEB wound progression to predict wound outcome and design betted wound management approaches.

OBJECTIVES

To better define mechanisms influencing RDEB wound progression by evaluating changes in molecular and cellular networks.

METHODS

We developed a non-invasive approach for sampling and analysis of wound-associated constituents using wound-covering bandages. Cellular and molecular components from seventy-six samples collected from early, established and chronic RDEB wounds were evaluated by FACS-based immuno-phenotyping and ELISA.

RESULTS

Our cross-sectional analysis determined that progression of RDEB wounds to chronic state is associated with the accumulation (up to 90 %) of CD16⁺CD66b⁺ mature neutrophils, loss of CD11b⁺CD68⁺ macrophages, and a significant increase (up to 50 %) in a number of CD11c⁺CD80⁺CD86⁺ activated professional antigen presenting cells (APC). It was also marked by changes in activated T cells populations including a reduction of CD45RO⁺ peripheral memory T cells from 80 % to 30 % and an increase (up to 70 %) in CD45RA⁺ effector T cells. Significantly higher levels of MMP9, VEGF-A and cathepsin G were also associated with advancing of wounds to poorly healing state.

CONCLUSIONS

Our data demonstrated that wound-covering bandages are useful for a non-invasive sampling and analysis of wound-associated constituents and that transition to poorly healing wounds in RDEB patients as associated with distinct changes in leukocytic infiltrates, matrix-remodeling enzymes and pro-angiogenic factors at wound sites.